JP2009220468A - Extrusion molding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extrusion molding apparatus which can obtain a molded article having high strength in all directions, in which heat is hardly generated, and whose power source can be made compact. <P>SOLUTION: The apparatus comprises a conveyance passage 2 for conveying a molding material, a die 3 arranged in the conveyance passage 2, and a screw 7 for extruding the molding material toward an extrusion hole 4 formed in the die 3, wherein a stirring means 10 is mounted on the tip end of the main shaft of the screw 7. The stirring means 10 is composed of two stirring pins 12, 13 extending nearly along the axial direction of the extrusion hole 4 and crossing each other. When the molding material containing reinforced fibers is pushed into the extrusion hole 4 of the die 3 by the screw 7, force in the rotating direction is simultaneously applied by the two stirring pins 12, 13 and a stirring effect is generated. As a result, the reinforced fibers f mixed in the molding material are present spirally or at random in the molded article C, reinforcing effect is generated not only in the axial direction, but also in the radial direction of the molded article C, thus, the molded article C hard to break in all directions can be obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an extrusion molding apparatus. More specifically, the present invention relates to an extrusion molding apparatus used for forming a molding material mixed with reinforcing fibers into a cylindrical or cylindrical molded product.

  In general, a catalyst, a catalyst carrier, an adsorbent, a drying material, a humidity control material, etc. are formed into a cylindrical or cylindrical molded product having a diameter of about 1 to 20 mm and a length of about 1 to 20 mm, and this is filled into a reactor. Used in various chemical reaction processes. In order to produce such a molded article such as a catalyst, an extrusion molding apparatus has been conventionally used.

  The molded article is made of, for example, a soft clay-like material such as alumina, which is continuously extruded from a die to be formed into a rod-shaped article, and is further cut into a cylindrical shape or a cylindrical shape.

  By the way, if the molded product is only the clay-like material as the main material, the strength is weak and it is easy to break, and therefore, reinforcing fibers are mixed into the molding material to improve the strength. However, a molded article produced by extrusion molding has a problem that it is easily broken even when reinforcing fibers are dispersed, when an impact such as dropping on the floor is applied. In particular, a cylindrical molded product was easily broken in the axial direction. This is because, as shown in FIG. 5 (B), the reinforcing fibers f included in the extruded product C are aligned in the extrusion direction in the same manner as the molded product C. Therefore, the reinforcing fibers have a radial strength. This is because it did not contribute to improvement.

  Patent Document 1 discloses an extrusion molding apparatus that considers changing the orientation direction of reinforcing fibers in such a molded article. In this apparatus, stirring means is attached to a screw shaft, and this stirring means is configured to rotate inside an extrusion hole formed in a die. As the agitation means, one pin that extends in the axial direction within the extrusion hole and a protrusion that extends in the radial direction is attached to this pin. According to this conventional technique, the reinforcing fibers in the molding material are randomly dispersed during extrusion, and the mechanical strength is improved.

  However, in the above prior art, the protrusion extending in the radial direction in the extrusion hole rotates, but the protrusion exists in a direction perpendicular to the extrusion direction of the molding material, so that the extrusion resistance is large and a large extrusion power is required. Further, since the protrusions tend to hinder the flow of the extruded material, the amount of generated heat is large, and extrusion failure is likely to occur.

JP 2006-272961

  In view of the above circumstances, an object of the present invention is to provide an extrusion molding apparatus that can obtain a molded product having high strength in all directions, is less likely to generate heat, and can reduce the size of a power source.

An extrusion molding apparatus according to a first aspect of the present invention is an extrusion molding apparatus provided with a die for extruding a molding material mixed with reinforcing fibers and a conveying means for extruding the molding material toward an extrusion hole formed in the die. The stirring means is attached to the tip of the main shaft of the conveying means, and the stirring means is located inside the extrusion hole, and the stirring means comprises two stirring pins, and the two stirring means The pins extend substantially along the axial direction of the extrusion hole and intersect each other.
The extrusion molding apparatus according to a second aspect of the present invention is the extrusion molding apparatus according to the first aspect, wherein the two agitation pins are both attached at the proximal end to the distal end of the main shaft of the conveying means, and the distal end is on the exit side of the extrusion port. It is directed and crosses in the middle part of each other.
The extrusion molding apparatus according to a third aspect of the present invention is the extrusion molding apparatus according to the first aspect, wherein the two agitation pins are both attached at the base end to the front end of the main shaft of the conveying means, and the front end is on the exit side of the extrusion port. It is directed and crosses at the base end of each other.

According to the first invention, when the molding material containing the reinforcing fibers is pushed into the extrusion hole of the die by the conveying means, it is simultaneously stirred by the rotation of the two stirring pins as the stirring means. In addition, when the two agitating pins intersect, the agitation effect is produced in a long axial region within the extrusion hole, so that the molding material is extruded from the extrusion hole while receiving a force in the rotational direction. For this reason, the reinforcing fibers mixed in the molding material also exist spirally or randomly in the molded product, and a reinforcing effect is generated not only in the axial direction but also in the radial direction of the molded product, and is difficult to crack in all directions. A molded product is obtained. Further, since the stirring pin extends along the coaxial direction in the extrusion hole, the resistance when the molding material passes through the extrusion hole is reduced. For this reason, it is hard to produce the shaping | molding defect by heat_generation | fever and an extrusion drive source can also be reduced in size.
According to the second aspect of the invention, since the two stirring pins intersect each other at the intermediate portion, the distance between the base ends of the two stirring pins can be widened, and the resistance against the stirring resistance is increased. In addition, since the stirring effect can be generated in the entire radius region from the center position in the flow path cross section of the extrusion hole to the inner periphery of the extrusion hole, it is easy to perform spiral or random orientation of the reinforcing fibers. In addition, since the two stirring pins follow the flow of the molding material extruded through the extrusion hole, the flow resistance is reduced. For this reason, the heat generation of the molding material is reduced, molding defects are less likely to occur, and the extrusion drive source can be miniaturized.
According to the third aspect of the invention, since the two agitation pins intersect with each other at the base end portions, the distance between the tips of the two agitation pins can be widened and agitation can be greatly performed. In addition, since the stirring effect can be generated in the entire radius region from the center position in the flow path cross section of the extrusion hole to the inner periphery of the extrusion hole, it is easy to perform spiral or random orientation of the reinforcing fibers. In addition, since the two stirring pins follow the flow of the molding material extruded through the extrusion hole, the flow resistance is reduced. For this reason, the heat generation of the molding material is reduced, molding defects are less likely to occur, and the extrusion drive source can be miniaturized.

Next, an embodiment of the present invention will be described with reference to the drawings.
The extrusion molding apparatus of the present invention is an apparatus for producing a molded product by pressure-conveying a molding material in which reinforcing fibers are mixed into a clay-like material, and extruding it from a die. In the following example, the case where the conveying means is a screw type will be described as a representative, but the conveying method (extrusion mechanism) of the molding material is not particularly limited.

  The molding material molded by the extrusion molding apparatus of the present invention is a mixture of reinforcing fibers. Examples of the reinforcing fibers to be mixed include alumina, silica alumina, quartz, glass, silicon carbide, silicon nitride, and aluminum borate. In addition, known materials having a fiber diameter of 0.1 to 20 μm and a fiber length of 1 to 1000 μm can be exemplified, but the present invention is not limited thereto.

An outline of the extrusion molding apparatus of the present invention will be described with reference to FIG.
In the same figure, the code | symbol 2 has shown conveyance paths, such as a screw case. A hollow cylindrical space is formed in the transport path 2, and a die 3 is provided at one end of the transport path 2 in the axial direction. An extrusion hole 4 is formed in the center of the die 3.

  The transport passage 2 is provided with a hopper 5 for supplying a molding material into the transport passage 2. In this example, the molding material is supplied into the conveyance path 2 through the hopper 5, but the method of supplying the molding material into the conveyance path 2 is not particularly limited.

A screw 7 as a conveying means is disposed in the space in the conveying passage 2, and the base end of the screw 7 is connected to a drive source 9 such as a motor via a speed reducer 8.
The screw 7 is composed of a main shaft 7 a and blades 7 b, and the main shaft 7 a is disposed concentrically with the extrusion hole 4 formed in the die 3.
And the stirring means 10 which concerns on this invention is attached to the front-end | tip of the main axis | shaft 7a, The detail is mentioned later.

Since it is the above structure, if the molding material containing a reinforcing fiber is supplied into the conveyance path 2 through the hopper 5 and the screw 7 is rotated, the molding material is conveyed toward the die 3 while being pressurized. .
And a molding material is extruded from the extrusion hole 4 of the die | dye 3, and comes out as a cylindrical molded product containing a reinforcing fiber, and a cylindrical molded product is cut | disconnected by predetermined length.

By the way, as means for orienting the reinforcing fibers spirally or randomly in the molded product, a stirring means 10 attached to the main shaft 7a of the screw 7 is employed in the present invention.
Next, the stirring means 10 will be described with reference to FIGS.

(First embodiment)
2A is a sectional view showing the stirring means 10 and the die 3 according to the first embodiment of the present invention, FIG. 2B is an enlarged side view of the stirring means 10, and FIG. 2C is a front view thereof. is there.
The stirring means 10 of the first embodiment includes a boss portion 11 and two stirring pins 12 and 13. The boss portion 11 is a member having substantially the same diameter as the main shaft 7a of the screw 7, and has a screw portion 11a at the rear end thereof. This screw portion 11a is a member for attaching the stirring means 10 to the main shaft 7a.

  The proximal ends of the two stirring pins 12 and 13 are attached to the boss portion 11 by implantation or other means. Further, the two stirring means 12 and 13 both extend substantially along the axial direction toward the exit side of the extrusion hole 4. The two stirring pins 12 and 13 do not have to exist over the entire length of the extrusion hole 4, and may have a length from the entry side of the extrusion hole 4 to the middle of entry. The longer the length of each stirring pin 12, 13 is, the higher the stirring effect is. However, how long is the length, and what is the length between the outlet end of the extrusion hole 4 and the stirring pins 12, 13? The degree may be selected according to the properties of the molding material and the amount of reinforcing fibers mixed therein.

The two agitation pins 12 and 13 intersect each other at an intermediate portion. In other words, it is X-shaped when viewed from the side.
In the illustrated embodiment, the crossing angle θ with respect to the axis of each stirring pin 12, 13 is 8 °, but may be smaller or larger. In short, it can be inserted into the extrusion hole 4 and the molding material and the reinforcing fibers contained therein can be stirred.

  Since the two agitation pins 12 and 13 in the present embodiment intersect with each other in the middle, the distance between the base ends of the two agitation pins 12 and 13 can be widened. In other words, the distance between the tips is narrowed, but the bending moment applied to the base ends of the stirring pins 12 and 13 is small, so it can be said that the resistance against stirring resistance is large. When the stir pins 12 and 13 are viewed in the cross section of the extrusion hole 4, the stir pins 12 and 13 are present in the entire radius region from the center position of the push hole 4 to the inner periphery of the push hole 4. Therefore, the stirring effect when this rotates is large. For this reason, as shown to FIG. 5 (A), the direction of the reinforcement fiber f in the molded article C can be oriented helically or at random.

  Moreover, in this embodiment, since the two stirring pins 12 and 13 are along the flow of the molding material extruded in the extrusion hole 4, flow resistance becomes small. For this reason, the heat generation of the molding material is reduced, molding defects are less likely to occur, and the extrusion drive source can be miniaturized.

(Second Embodiment)
3A is a sectional view showing the stirring means 10 and the die 3 according to the second embodiment of the present invention, FIG. 3B is an enlarged side view of the stirring means 10, and FIG. 3C is a front view thereof. is there.
The basic configuration of the agitation unit 10 of the second embodiment, which includes the boss portion 11 and the two agitation pins 12 and 13, is the same as that of the agitation unit 10 of FIG. Further, the agitation pins 12 and 13 of the present embodiment have their proximal ends attached to the boss portion 11 by means of meditation or other means. Further, the two stirring means 12 and 13 both extend substantially along the axial direction toward the exit side of the extrusion hole 4. These two stirring pins 12 and 13 do not need to exist over the entire length of the extrusion hole 4, and may have a length from the entry side of the extrusion hole 4 to the middle of entry. The longer the length of each stirring pin 12, 13 is, the higher the stirring effect is. However, how long is the length, and what is the length between the outlet end of the extrusion hole 4 and the stirring pins 12, 13? The degree may be selected in accordance with the properties of the molding material and the amount of reinforcing fibers mixed therein.

The two stirring pins 12 and 13 intersect with each other at their base ends. In other words, it has a V-shape that is lateral in a side view.
In the illustrated embodiment, the crossing angle θ with respect to the axis of each stirring pin 12, 13 is 6 °, but may be smaller or larger. In short, it can be inserted into the extrusion hole 4 and the molding material and the reinforcing fibers contained therein can be stirred.

  Since the two agitation pins 12 and 13 in the present embodiment intersect with each other at their base ends, the distance between the tips of the two agitation pins 12 and 13 can be widened and agitation can be greatly performed. When the stir pins 12 and 13 are viewed in the cross section of the extrusion hole 4, the stir pins 12 and 13 are present in the entire radius region from the center position of the push hole 4 to the inner periphery of the push hole 4. Therefore, the stirring effect when this rotates is large. As shown in FIG. 5A, the direction of the reinforcing fiber f in the molded product C can be oriented spirally or randomly.

  Also in this embodiment, since the two stirring pins 12 and 13 are along the flow of the molding material extruded through the extrusion hole 4, the flow resistance is reduced. For this reason, the heat generation of the molding material is reduced, molding defects are less likely to occur, and the extrusion drive source can be miniaturized.

(Third embodiment)
4A is a cross-sectional view showing the main part of an extrusion molding apparatus according to the third embodiment of the present invention, and FIG. 4B is a front view thereof.
The present embodiment is an extrusion molding apparatus having a plurality of extrusion holes 4. As shown in the figure, a die 3 is provided at the tip of the main transport passage 22 containing the main transport means 27. A plurality of transport passages 2 are formed in the die 3, and the transport passages 2 are arranged at equal intervals on the circumference when viewed from the front, and the transport passages 2 are connected to the main transport passage 22. Communicate. Further, an extrusion hole 4 is formed at the tip of each transport passage 2.

A screw 7 as a conveying means is disposed in each conveying passage 2, and the stirring means 10 of the first embodiment or the second embodiment is attached to the tip of the main shaft of the screw 7.
In this embodiment, the length of the cylindrical or cylindrical molded product extruded from the extrusion hole 4 can be varied by adjusting the number of rotations of the screw 7 to be different in each extrusion hole 4.

Further, in each of the illustrated embodiments, the stirring means 10 is fixedly attached to the main shaft 7a of the screw 7. However, as shown in FIG. 4, the stirring means 10 individually rotates on a shaft different from the main shaft 7a. You may do it.
In this case, a drive shaft 10a for the stirring means 10 is rotatably inserted into the main shaft 7a in a concentric manner, and the stirring means 10 is mounted with the tip of the drive shaft 10a protruding from the main shaft 7a. By connecting the end to a driving source such as a motor, the end can be rotated separately from the screw 7.

  In this embodiment, the stirring means 10 having a different number of grooves can be appropriately replaced with the main shaft 7a of the screw 7, and the stirring means 10 can be rotated at a rotational speed suitable for the number of grooves. For this reason, the operation | movement according to the property of a reinforcement fiber and a molding material is attained. Further, in order to add optimum stirring to the columnar or cylindrical molded product extruded from the respective extrusion holes 4, the rotational speed of the stirring means 10 may be made the same as or different from the rotational speed of the screw 7. It becomes possible.

Next, another embodiment of the present invention will be described.
In the first, second, and third embodiments, the stirring means 10 has the two stirring pins 12 and 13 formed in an X shape or a lateral V shape. The present invention includes those in which the intersecting portions of the stirring pins 12 and 13 are closer to the proximal end side and those in which the stirring pins 12 and 13 are closer to the distal end side. In these embodiments as well, substantially the same stirring effect as in the above embodiments is exhibited.

  In each of the embodiments described above, the stirring means 10 has two stirring pins 12 and 13 attached to the boss portion 11, but one cylindrical molding pin may be attached to the boss portion 11. This pin is longer than the stirring pins 12 and 13 and is attached along the central axis. In this embodiment, the molding material flows along the periphery of the pin during extrusion molding, so that it becomes easy to mold a cylindrical molded product.

  In any of the above-described embodiments of the present invention, the stirring means 10 extends in the substantially coaxial direction in the extrusion hole 4, so that the resistance when the molding material passes through the extrusion hole 4 is small. For this reason, since the calorific value of the molding material is small, molding defects due to heat generation are unlikely to occur. Further, since the flow resistance of the molding material is small, a force in the rotational direction can be applied at a low rotational speed or low stirring power, and the power source of the stirring means 10 can be reduced in size.

It is a schematic sectional drawing of the extrusion molding apparatus of this invention. (A) The figure is sectional drawing which shows the stirring means 10 and die | dye 3 which concern on 1st Embodiment of this invention, (B) The figure is an expanded side view of the stirring means 10, (C) The figure is the same front view. (A) is a sectional view showing a stirring means 10 and a die 3 according to a second embodiment of the present invention, (B) is an enlarged side view of the stirring means 10, and (C) is a front view of the same. (A) The figure is sectional drawing which shows the principal part of the extrusion molding apparatus which concerns on 3rd Embodiment of this invention, (B) The figure is the same front view. (A) is an explanatory view of a molded product molded by the extrusion molding apparatus of the present invention, and (B) is an explanatory diagram of a molded product molded by a conventional apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Extrusion molding apparatus 2 Conveyance path 3 Dies 4 Extrusion hole 7 Screw 10 Stirring means 12, 13 Stirring pin

Claims (3)

An extrusion molding apparatus comprising a die for extruding a molding material mixed with reinforcing fibers and a conveying means for extruding the molding material toward an extrusion hole formed in the die,
A stirring means is attached to the tip of the main shaft of the conveying means,
The stirring means is located inside the extrusion hole,
The agitation means comprises two agitation pins, and the two agitation pins extend substantially along the axial direction of the extrusion hole and intersect each other. Each of the two stirring pins has a proximal end attached to the distal end of the main shaft of the conveying means, the distal end is directed to the exit side of the extrusion port, and intersects at an intermediate portion of each other. The extrusion molding apparatus according to claim 1, wherein Each of the two stirring pins has a proximal end attached to the distal end of the main shaft of the conveying means, the distal end is directed to the exit side of the extrusion port, and intersects at the proximal end portion of each other. The extrusion molding apparatus according to claim 1, wherein

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