JP2857574B2 - Extrusion molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an extruder for reducing the volume using a screw shaft.

[0002]

2. Description of the Related Art Scraps of discarded automobiles and electric products are separated into recycled ferrous and non-ferrous metals and garbage mixed with rubber products and plastic products. The garbage is then subjected to volume reduction processing in an extruder, and is disposed of at a landfill or used for energy recovery by combustion.

[0003] As extruder of this type, JP 6 3 -
Japanese Patent Application Laid-Open No. 214421 and Japanese Utility Model Application Laid-Open No. 1-9724 have conventionally been known.

[0004] JP 6 3 of JP -214421 ones, as shown in FIGS. 6 and 7, the interior of the outer cylinder 41, two screw shafts rear end is connected to the driving motor 44 42,4
3 are arranged side by side, and a tapered cone portion 45 and a tapered portion 46 are provided at the tip end of each of the screw shafts 42 and 43 and the outer cylinder 41, respectively.
And a nozzle 48 for discharging the material is provided at the tip.

[0005] A die plate 49 having a plurality of die holes 50 is attached to the rear end side of the tapered cone portion 45 of the screw shafts 42, 43.
Are provided with spiral feed blades 51 and 52 that are twisted in opposite directions to each other.

In the above extruder, each screw shaft 4
By rotating the members 2 and 43 in the opposite directions, the material charged into the outer cylinder 41 is sent to the distal end side by the feed blades 51 and 52, and is primarily compressed by pushing the material out of the die holes 50 of the die plate 49. The compressed material is secondarily compressed while moving through the screw shafts 42 and 43 and the tapered cone portion 45 and the tapered portion 46 of the outer cylinder 41, and is discharged from the nozzle 48.

On the other hand, the extruder disclosed in Japanese Utility Model Laid-Open Publication No. Hei 1-9724 eliminates the die plate 49 from the outer cylinder 41 as shown in FIG. The surface is provided with an inclined surface narrowing portion 55 for rapidly reducing the cross-sectional area of the gap, and the material is primarily compressed by the narrowing portion 55.

In each of the two extruders, the material is compressed by the squeezing effect and frictional resistance while the volume of the material is reduced inside the outer cylinder 41, and the plastic and the like inside the material are melted by the frictional heat generated at the same time. To solidify. Also,
When the material contains a large amount of water inside, the water is removed by the compressing action and the frictional heat, so that a material having a low water content can be obtained.

[0009]

The object of the invention is to be Solved However, JP-A-6 3
The extrusion molding machine disclosed in Japanese Patent Application Publication No.
Since it is necessary to forcibly extrude from the die hole 50 of the die plate 49 inside, if a long foreign material such as an electric wire or a wire is included in the material, the foreign material extends over several die holes 50 of the die plate 49. If it is caught, there is a problem that the material does not come off by extrusion of the material and stays inside the outer cylinder 41. When the long foreign matter enters the die hole 50, it closes the die hole and sometimes makes it impossible to extrude the material.

Each of the screw shafts 42 and 43 is supported at its rear end by a bearing 53 and at its front end by a metal bearing 54 provided in a die plate 49.
Since the supporting portion is in the vicinity of the compressed portion of the material and a large compressive force acts thereon, the material easily enters the metal bearing 54, thereby causing abnormal wear on the sliding surface and supporting the screw shafts 41 and 42. There is a problem that the state becomes unstable.

On the other hand, in the extruder disclosed in Japanese Utility Model Laid-Open Publication No. 1-9724, each of the screw shafts 42 and 43 is supported at the rear end connected to the driving device 44, but the front end is where the material is compressed and discharged. Has no support and has a cantilevered structure.

For this reason, each of the screw shafts 42 and 43 cannot have a sufficient strength against the force for bending the screw shafts, and a large deflection may occur during the material volume reduction processing. Further, when the screw shaft is bent, the deformation causes a large gap between the outer cylinder 41 and the screw shafts 42 and 43. Therefore, when a foreign matter such as a metal piece is caught, it becomes difficult to remove the foreign matter. There is a problem that foreign matter stays in the inside.

In order to reduce the deflection of the screw shafts 42 and 43, it is necessary to increase the diameter of each screw shaft. There is a problem that the power consumption of the G.44 increases.

Further, in the structure of the two extruders described above, the reduced volume material is discharged from the nozzle 48 of the outer cylinder 41 simply by the feed action of the feed blades 51, 52 of the screw shafts 42, 43. Therefore, if there is a variation in material input, there is also a variation in material discharge speed, and there is a problem that stable extrusion performance cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and can stably support two screw shafts with high rigidity, and can prevent a long foreign substance or the like from stagnating inside an outer cylinder. Can be discharged without causing
Moreover, it is an object of the present invention to provide an extruder capable of maintaining stable extrusion performance.

[0016]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention extends the tip of each screw shaft in the axial direction to project from a nozzle to the outside of an outer cylinder. It was a supported structure.

In a second aspect of the present invention, a protrusion having an inclination in the axial direction is arranged on a peripheral surface of an extension of each of the screw shafts. Therefore, it was set so that a force toward the nozzle outlet acts.

Further, a third means is to set the cross-sectional area between the extension of the screw shaft and the inner surface of the nozzle to be smaller than the minimum cross-sectional area between the screw shaft and the tapered portion at the tip of the outer cylinder. A compressed part of the material was formed between the part and the nozzle.

Further, in each of the above structures, at least a portion of the tip end side from the tapered portion of each screw shaft can be axially divided, and a portion of the outer cylinder corresponding to the dividable portion is formed so as to be dividable. Is good.

[0020]

As described above, by supporting the extended end of the screw shaft with the bearing, the screw shaft can be reliably supported at both ends, and the deflection of the screw shaft can be reduced. Further, since the distal end of the screw shaft is supported outside the outer cylinder, no material enters the bearing.

Further, by providing a projection on the peripheral surface of the extension as in the second means, the material can be forcibly discharged from the nozzle with the rotation of the screw shaft, and the material discharge speed can be stabilized. Can be obtained. In addition, even if foreign matter is mixed in the material, the foreign matter can be discharged from the nozzle by the rotation of the screw shaft and the feeding action of the projection, and the stagnation of the foreign matter in the outer cylinder can be prevented.

On the other hand, when the portion between the extending portion and the nozzle is a compressed portion of the material as in the third means, the compressibility of the material can be increased, and the design range in which the compressed portion can be formed can be increased.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. As shown in FIGS. 1 to 3, two screw shafts 2 and 3 are arranged in parallel inside an outer cylinder 1, and a driving machine 4 is connected to the rear end of each screw shaft 2 and 3. I have.

The rear ends of the screw shafts 2 and 3 are rotatably supported by bearings (not shown) incorporated in the drive unit 4, and the drive unit 4 controls the rotation of the motor 5. A power transmission unit 6 is provided for transmitting the rotational driving force to the screw shafts 2 and 3 in the opposite direction.

The outer cylinder 1 has a material inlet 7 at the rear end and a tapered conical tapered portion 8 formed at the front end. The material discharge port is formed at the front end of the tapered portion 8. Nozzle 9 is provided.

Each of the screw shafts 2 and 3 has a cylindrical portion 10 having a peripheral surface inside the outer cylinder 1 having substantially the same diameter, and a distal end of the cylindrical portion 10 corresponds to the tapered portion 8 of the outer cylinder 1. A tapered cone portion 11 having a tapered inclined surface is provided.

The distal end of the tapered cone portion 11 is a cylindrical extension 12 projecting in the axial direction. The extension 12 projects outside from the nozzle of the outer cylinder 1 and extends therefrom. Is rotatably supported by a bearing 14 and a support base 15.

On the peripheral surface of the cylindrical portion 10 of each of the screw shafts 2 and 3, spiral feed blades 16 and 17 are formed, which are twisted in the axial direction, respectively. Spiral projections 18 and 19 that are twisted in the direction are formed. As shown in FIG. 5, the feed blades 16 and 17 and the spiral projections 18 and 19 are formed so as to have respective twists in opposite directions. Is set so that the material between the outer cylinder 1 and the screw shaft exerts a pressing force toward the nozzle 9 of the outer cylinder 1 when rotated.

The extension 12 of each of the screw shafts 2 and 3
A plurality of inclined projections 20 and 21 are formed on the peripheral surface of the outer cylinder 1 in the range of the length of the nozzle 9 of the outer cylinder 1. Each projection 2
Reference numerals 0 and 21 denote the feed blades 16 and 17 and the spiral protrusion 1.
It has a twist in the same direction as 8 and 19, and has a function of sequentially sending out the material that has entered the inside of the nozzle 9 toward the outlet when the screw shafts 2 and 3 rotate.

The gaps 22 between the cylindrical portions 10 of the screw shafts 2 and 3 and the inner surface of the outer cylinder 1 are substantially the same size in the axial direction. A narrowed portion 13 is formed which is inclined in a direction in which the cross-sectional area of the gap 22 is sharply reduced, and the narrowed portion 13 forms a primary compression portion for reducing the volume of the material.

The gap 23 between each tapered cone portion 11 and the inner surface of the tapered portion 8 of the outer cylinder 1 is set to have substantially the same size in the radial direction. Has a conical shape whose diameter gradually decreases, so that the cross-sectional area of the gap 23 gradually decreases toward the distal end side. For this reason, the material is not
Is moved, the volume is reduced as the cross-sectional area is reduced, and the space between the tapered cone portion 11 and the tapered portion 8 forms a secondary compression portion.

Further, an extension 1 of each of the screw shafts 2 and 3
The annular gap 24 formed between the inner surface of the nozzle 2 and the inner surface of the nozzle 9 is
The cross-sectional area is set so as to be smaller than the minimum cross-sectional area in the gap 23 between the tapered cone portion 11 and the tapered portion 8. Is to be done. That is, the annular gap 24 between the extension 12 and the nozzle 9 forms a tertiary compression section.

On the other hand, the screw shafts 2 and 3 are
As shown in the figure, the cylindrical portion 10 is formed of a hollow rear member 25 and a front member 26 which are divided from each other, and a connecting shaft 27 of the driving machine 4 is connected to a rear end of the rear member 25 via bolts. ing.

A guide shaft 28 is integrally fixed to the distal end of the rear member 25 by welding or the like.
A front member 26, a tapered cone portion 11, and a cylindrical sleeve 29 for abrasion are fitted around the outer periphery of the front member 26.

Further, a fastener 30 is attached to the tip of the guide shaft 28, and the fastener 30 is fixed to the front member 26, the tapered cone portion 11, and the sleeve 2 by tightening a screw.
9 is pressed against the end face of the rear member 25 and fixed integrally. Reference numeral 31 denotes a key for preventing the taper cone 11 and the guide shaft 28 from rotating.

The outer cylinder 1 has a front member 2 of a screw shaft.
6 can be divided into a front case 32 and a rear case 33 at a position closer to the rear from a connection portion between the rear case 25 and the rear member 25.
Are connected integrally.

The extruder of the embodiment has the above-mentioned structure, and its operation will be described below. When the material for molding is charged from the charging port 7 of the outer cylinder 1 and each of the screw shafts 2 and 3 is rotated in the opposite direction, the material is moved between the outer cylinder 1 and the screw shafts 2 and 3 by the action of the feed blades 16 and 17. The gap 22 is fed toward the distal end side.

This material is used as the squeezed portion 1 of the screw shafts 2 and 3.
When it reaches 3, it undergoes an abrupt reduction in the cross-sectional area and is primarily compressed. Next, during the passage through the gap 23 between the tapered cone portion 11 and the tapered portion 8, the volume is reduced due to a change in the cross-sectional area of the gap 23, and the secondary compression is performed.

In the above-mentioned primary compression and secondary compression, the material is forcibly moved in the section where the cross-sectional area is reduced, the rotation of the screw shafts 2 and 3 and the feed blades 16 and 17 and the spiral projections 18 and 19 are performed. Due to a large drawing effect and frictional resistance due to the feed force, the mixture is sufficiently kneaded and compressed.

The material is heated from the inside by the frictional heat generated by the frictional resistance, and the plastic and the like contained in the material are melted and solidified together with other components.

Further, when the material is a highly water-containing material containing a large amount of water therein, water is removed by the above-described squeezing effect and frictional resistance, and the water content is significantly reduced.

At the time of the above-mentioned compression work, the outer cylinder 1 may be heated from the outside, and the melting of the material and the removal of moisture may be promoted by frictional heat from the inside and external heating.

The material secondarily compressed between the tapered cone portion 11 and the tapered portion 8 then enters the annular gap 24 between the extended portion 12 and the nozzle 9 by the projections 20 and 21 provided on the extended portion 12. It is sent toward the nozzle 9 outlet, and during this movement, it is further compressed by the difference in the cross-sectional area between the above-mentioned gap 23 and the annular gap 24, and is tertiary compressed.

In this case, since the protrusions 20 and 21 provided on the extension portion 12 apply a mechanical feed force to the material that has entered the annular gap 24, the material is forcibly fed at a constant speed, and 9 is always discharged at a stable speed. For this reason, even if the input speed of the material supplied from the input port 7 of the outer cylinder 1 varies, the material is discharged from the nozzle 9 at a substantially constant discharge speed, and a stable extrusion performance is obtained. Can be.

In the above structure, if the pitch or height of the projections 20 and 21 of the extension portion 12 is changed, the magnitude of the feeding force to the material changes. Therefore, the pitch and size of the projections are arbitrarily set. By doing so, the material discharge speed and the volume reduction rate can be adjusted within an appropriate range.

In the extruder of this embodiment, the tip of each of the screw shafts 2 and 3 for performing the compression process is a bearing 14.
, The support rigidity of the screw shaft is increased, and the amount of deflection of each screw shaft 2, 3 can be suppressed even if a bending force is applied during the extrusion operation. Therefore, the gap between each of the screw shafts 2, 3 and the outer cylinder 1 is always kept constant, and stable extrusion can be performed.

Further, since the tip portions of the screw shafts 2 and 3 are supported outside the outer cylinder 1, the material to be molded does not bite into the bearing portion, and a stable supporting state can be maintained. it can.

In the case where foreign matter such as an electric wire or a wire is mixed in the material, there is no die plate inside the outer cylinder 1.
Since the gap between each of the screw shafts 2 and 3 and the outer cylinder 1 has a continuous shape, the foreign matter is sent to the inlet of the nozzle 9 without being caught on the way. In addition, the foreign matter and the metal pieces that have entered the nozzle 9 are
Since the feeding force is received by the nozzle 21, it is forcibly discharged from the outlet of the nozzle 9 and does not stay inside the outer cylinder 1.

Further, the tapered cone portion 11 and the throttle portion 13 of each of the screw shafts 2 and 3 performing a compressing action, and the outer cylinder 1
The inner surface of the front case 32 is greatly abraded due to a large friction between the material and the material. However, the above-described structure includes the tapered cone portion 11 and the throttle portion 13 by removing the fasteners 30 and the bolts 34. Since the front member 26, the front case 32 of the outer cylinder 1, and the like can be easily disassembled, repair and replacement of the surfaces thereof can be easily performed.

In the above-described embodiment, the throttle portion 13 is provided in the middle of the screw shafts 2 and 3 to perform the primary compression.
The material may be subjected to primary compression and secondary compression between the tapered portion 8 and the extended portion 12 and the nozzle 9.

The projections 20 and 21 provided on the extension 12
May be continuous spiral projections, or a plurality of small projections may be spirally arranged, as long as they are arranged so that an axial feed force is applied to the material.

Further, the divided structure of the screw shafts 2, 3 and the outer cylinder 1 is not limited to the structure shown in FIG. 3, but can be divided into at least the tapered cone portion 11 including the throttle portion 13 and the tapered portion 8. Should be fine.

[0053]

As described above, according to the present invention, since both ends of the screw shaft are supported, the deflection of the screw shaft during the extrusion operation can be suppressed small, and stable extrusion can be performed. Further, since the bearing that supports the tip of the screw shaft is outside the outer cylinder, it is possible to prevent the material from entering the bearing portion.

Further, when a projection for feeding is provided on the extension of the screw shaft as in the second means, the speed of discharging the material can be controlled to be constant, and foreign materials and metal pieces contained in the material are forcibly removed. It is possible to discharge the foreign matter, and to prevent stagnation of foreign matter inside the outer cylinder.

Further, by using the nozzle of the outer cylinder for the compression section as in the third means, the compression ratio of the material can be increased, and the position where the compression section can be formed is increased. There is an advantage that the degree of freedom in design can be increased.

[Brief description of the drawings]

FIG. 1 is a front view showing an extruder according to an embodiment.

FIG. 2 is a partial cross-sectional plan view of the above.

FIG. 3 is a partially longitudinal front view showing the inside of the outer cylinder according to the first embodiment;

FIG. 4 is an enlarged longitudinal sectional front view of a main part of the above.

FIG. 5 is a sectional view taken along the line VV in FIG. 3;

FIG. 6 is a partially longitudinal front view showing a conventional example.

FIG. 7 is a cross-sectional plan view of the above.

FIG. 8 is a longitudinal sectional front view showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer cylinder 2, 3 Screw shaft 4 Drive 7 Input port 8 Taper part 9 Nozzle 10 Cylindrical part 11 Tapered cone part 12 Extension part 14 Bearing 16, 17 Feed blade 18, 19 Spiral projection 20, 21, Projection 22, 23 Gap 24 Annular gap 28 Guide shaft 30 Fastener

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-249319 (JP, A) JP-A-63-214421 (JP, A) JP-A-6-467 (JP, A) JP-A-6-467 79724 (JP, A) Japanese Utility Model Showa 58-171328 (JP, U) Japanese Utility Model Showa 60-32010 (JP, U) Japanese Patent Publication No. 4742583 (JP, B1) (58) Field surveyed (Int. ⁶ , DB name) B29C 47/00-47/96 B29B 17/00-17/02

Claims (4)

(57) [Claims] 1. Two screw shafts each having a rear end connected to a driving machine are arranged in parallel inside an outer cylinder, and each of the screw shafts and a distal end of the outer cylinder are provided with a tapered tapered portion. A material inlet is provided at the rear end, a nozzle for material discharge is provided at the front end, and spiral feed blades that are twisted in opposite directions are provided on the peripheral surface of each of the screw shafts, and the screw shafts are set in opposite directions. In the extrusion molding machine, in which the material charged into the outer cylinder is sent to the distal end side of the outer cylinder by the feed blades by rotating the screw to reduce the volume between each screw shaft and the outer cylinder and discharge from the nozzle, An extruder wherein the tip is extended in the axial direction to project from the nozzle to the outside of the outer cylinder, and the projecting extension is supported by a bearing. 2. A peripheral surface of an extension of each screw shaft,
2. The extrusion molding according to claim 1, wherein a projection having an inclination in the axial direction is arranged, and the projection is set such that a force toward the nozzle outlet acts on the material when each screw shaft rotates. Machine. 3. A cross-sectional area between the extension of the screw shaft and the inner surface of the nozzle is set smaller than a minimum cross-sectional area between a gap between the screw shaft and a tapered end of the outer cylinder. The extruder according to claim 1 or 2, wherein a compression section of (1) is formed. 4. The screw shaft according to claim 1, wherein at least a portion from the tapered portion to the tip end of each screw shaft is axially dividable, and a portion of the outer cylinder corresponding to the dividable portion is formed so as to be dividable. Item 5. The extrusion molding machine according to any one of Items 1 to 3.