JP2000210893A - Manufacture of rotary blade and synthetic resin porous pipe using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary blade which can manufacture a synthetic resin porous pipe generating no burr at the cut part, in which the form of the cut part is stabilized. SOLUTION: This synthetic resin porous pipe consists of a disk form rotary edge body 51 having a center hole, and a pair of circular members 53 and 53 to hold the rotary edge body 51 from its both sides, and the circular members have the diameter smaller than the rotary edge body, their peripheral surfaces 54 and 54 are formed in a taper form surface toward the rotary edge body, or a wall surface vertical to the rotary edge surface, and to the taper form surface or the vertical wall surface, uneven parts 55 are formed along the full periphery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary blade suitable for use in manufacturing a synthetic resin porous tube in which a part of the peripheral surface or the entire peripheral surface is formed in a grid-like mesh, and a rotary blade suitable for use. The present invention relates to a method for manufacturing a synthetic resin porous tube.

[0002]

2. Description of the Related Art As shown in FIG. 6, a porous portion of a synthetic resin tube is formed on a peripheral surface thereof along a longitudinal direction or on the entire peripheral surface in a grid-like mesh. This is suitable for drainage pipes and rainwater infiltration pipes in gutters buried in the ground, and those with meshes on the entire peripheral surface are suitable as strainers attached to the tips of water absorption pipes of wells.

[0003] Conventionally, these synthetic resin porous tubes can only be obtained as tubes of a predetermined length by injection molding using a mold. Unlike ordinary synthetic resin tubes, they are manufactured as a series of tubes by extrusion molding. Was considered impossible.

Therefore, the present inventor disclosed in Japanese Patent Laid-Open No. 2-52729.
In Japanese Patent Application Publication, a method and an apparatus for manufacturing a synthetic resin porous tube in which at least a part of the peripheral surface is formed in a lattice-like mesh by extrusion molding have been proposed. 7 to 10
The above device will be described with reference to FIG. FIG. 7 shows a side view of the entire apparatus, 1 is an extruder, 2 is an extrusion die, 3
Is a cooling water, and 4 is a tension roller. These are structurally similar to a normal extruder. However, the product a extruded from the extrusion die 2 has a pipe portion as shown in FIG. b is a tubular body having ribs (hereinafter also referred to as vertical ribs) c... along the longitudinal direction on a part of the inner surface thereof, and the tension roller 4 is slightly faster than the extrusion speed of the extruder 1. It is designed to forcibly pull the product a at a speed.

A cut forming mechanism 5 is connected to the outlet of the extrusion die 2 so as to form a spiral at regular intervals on the outer peripheral surface of the product a fed from the extrusion die 2. It is for attachment. As is apparent from FIGS. 8 to 10, the notch forming mechanism 5 can rotate the sprocket wheel 8 separately from the cylindrical body 7 on the outer surface of the cylindrical body 7 having a circular hole 6 through which the product a can pass. And a cutter 9 is provided on the plate surface of the sprocket wheel 8 so as to be slidable along a radial position, and the cutter 9 is separately inserted into and fixed to the cylindrical body portion 7 via a sprocket wheel 8. , And cuts the outer peripheral surface of the product a at its tip. That is,
The sprocket wheel 8 is rotatable by engaging a roller 11 pivotally supported on the plate surface thereof with the guide flanges 12, 13, and 14 of the cylindrical body portion 7, and the cutter 9 is mounted on the plate surface of the sprocket wheel 8. , One end of roller 1 by spring 15
6 is attached to a sliding member 17 which comes into pressure contact with the peripheral surface of the cam 10 via a spring 6, and the distal end is always brought into pressure contact with one end of the cylindrical body 7 via a spring 18. 19 is the cam 10
, A nut-like tightening ring for fixing the cylindrical body 7 to the extrusion die 2, and a chain 21.

According to the above configuration, a pellet-like thermoplastic resin as a raw material is supplied to an extruder 1 and an extruding mold 2 is provided.
Are formed in the upper half of the inner peripheral surface via the vertical ribs c..., And the product a is forcibly pulled out by the tension roller 4. Then, when the sprocket wheel 8 of the notch forming mechanism 5 is rotated via the chain 21, the cutter 9 slides via the cam 10 in which a half of the circumference is slightly formed in advance in accordance with the sectional shape of the product a. When the cutter tip passes through the upper half of the product a, it is cut into the product a. When the cutter tip passes through the lower half of the product a, the product a are cut while leaving the vertical ribs c... and are always pulled by the tension roller 4, so that the vertical ribs c... between the cuts are uniformly stretched. Thus, a synthetic resin tube as shown in FIG. 6 is continuously produced. As a result, it has become possible to provide a synthetic resin porous tube continuously, extremely efficiently, and at low cost.

[0007] In the above, the product a is a cylindrical body having a vertical rib formed on the entire inner peripheral surface thereof.
If a cam having a perfect circular shape along the cylindrical portion b of the product a is used, a synthetic resin porous tube having a porous surface as shown in FIG. 11 can be produced.

By the way, in the apparatus proposed above, a cutter is used as a means for forming a cut, but in this case, there are the following points to be further improved. (1) In the case where the outer peripheral surface of the synthetic resin tube is simply cut, it is very difficult to form the outer peripheral surface thereafter.
For this reason, the shape of the cut surface often depends on the material of the extrusion molding. (2) When a resin (for example, hard vinyl chloride) that increases the internal pressure of the extrusion die is used as a raw material,
When the extruded resin is released from the pressure at the exit of the mold, an expansion phenomenon occurs, so that the cut surface may be turned up and become sharp. This sharp shape
It is very disadvantageous to handle and, in the worst case, leads to injuries. (3) Deformation such as roll-up due to the cut causes variations in the outer diameter of the extruded product, and it is difficult to maintain the accuracy of the product.

[0009]

DISCLOSURE OF THE INVENTION The present invention has solved the above-mentioned demands and problems, and has a rotary blade and a rotary blade capable of producing a synthetic resin porous tube having a stable cut shape without curling up of a cut portion. It is an object to provide a manufacturing method using the same.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, the rotary blade main body includes a disk-shaped rotary blade main body having a central hole, and a pair of annular members that sandwich the rotary blade main body from both sides thereof, and each of the annular members has a smaller diameter than the rotary blade main body. And, the peripheral surface portion is formed on a tapered surface portion facing the rotary blade body or a wall surface portion perpendicular to the rotary blade surface,
In addition, there is provided a rotary blade characterized in that irregularities are formed on the tapered surface portion or the vertical wall surface portion at regular intervals over the entire circumference. Further, according to the present invention, in the above configuration, there is provided a rotary blade in which the annular member is made of a metal material. Further, according to the present invention, a spiral cut is formed on an outer peripheral surface of a synthetic resin tube having an inner vertical rib obtained by extrusion molding, and is used to manufacture a synthetic resin porous tube having a lattice-like mesh. A rotary blade having the above configuration is provided. According to the present invention, the rotary blade is rotatably disposed near the outlet of the extrusion molding die and around the product to be fed out, and the rotary blade itself is rotatably mounted,
Synthesizing characterized in that a groove is formed by an annular member of the rotary blade on the outer peripheral surface of a synthetic resin tube fed from the extrusion molding die, and a cut is formed by making a cut in the rotary blade body. A method for manufacturing a resinous porous tube is provided. Further, according to the present invention, in the above,
The resin material is set so that the outlet of the inner mold of the extrusion mold is slightly protruded from the outlet of the outer mold of the mold, and the rotary blade and the end face of the inner mold are in a press-cut state. And forming a notch by cutting off.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments according to the present invention will be described in detail below with reference to examples. 1A and 1B show a rotary blade 50 for producing a synthetic resin porous tube according to the present invention, wherein FIG. 1A is a perspective view showing a state of forming a cut, and FIG. 1B is a cross-sectional view taken along line AA of FIG. FIG. 2 is an exploded perspective view of the rotary blade 50. This rotary blade 50 is used to form a spiral cut on the outer peripheral surface of the synthetic resin tube a with inner vertical ribs obtained by extrusion when manufacturing a synthetic resin porous tube having a lattice network by extrusion. belongs to. As is apparent from these drawings, the rotary blade 50 is configured by sandwiching a rotary blade main body 51 from both sides thereof with a pair of annular members 53, 53. The pair of annular members 53 has a certain thickness, and the diameter thereof is slightly smaller than the diameter of the rotary blade main body 51 so that the cutting edge portion 52 of the rotary blade main body 51 is appropriately exposed. I have. An outer peripheral surface portion 54 of each annular member 53, 53,
54 are formed on a tapered surface portion facing the rotary blade main body 51 or on a wall surface perpendicular to the rotary blade surface, and the tapered surface portion or the vertical wall surface portion has irregularities 55. Is formed. 55
.. can be provided in the form of a jagged pattern provided on the periphery of a coin. 55
· Acts to increase the coefficient of friction at the contact portion between the rotary blade 50 and the product (synthetic resin pipe) a, and to eliminate the instability of the cut shape due to slip.

The diameter and thickness of the rotary blade main body 51 are as follows.
An appropriate size is selected and used depending on the size, material, and the like of the synthetic resin pipe a forming the cut.
Those having a thickness of about 0 mm and a thickness of about 1 to 3 mm are used. The size of the cutting edge portion 52 exposed from the annular members 53, 53 in the rotary blade main body 51 is also set to an appropriate value depending on the size, material, and the like of the synthetic resin pipe a forming the cut, but is usually about 2 to 5 mm. . In addition, each annular member 53, 53
The angle between the outer peripheral surface portions 54, 54 and the rotary blade surface is 45 to 45.
It can be about 90 degrees. By changing the angle and the size of the exposed cutting edge, the shape of the outer cut surface of the extruded product can be changed. Annular member 53
Various materials having a low heat storage effect can be used from the viewpoint of preventing sticking to the outer periphery of the extruded product, but from the viewpoint of ease of construction, metal materials are preferable, and specifically, aluminum, iron, copper, etc. Is preferred. Its thickness can be about 1-3 mm. The type of the cutting edge is preferably a single-edged one.

Next, a method of forming a cut in a product (synthetic resin pipe) a using the rotary blade 50 having the above-described configuration will be described. First, as shown in FIG. 3, the rotary blade 50 is rotatably (revolved) near the exit of the extrusion die 60 and around the product a to be fed. In this case, the rotary blade 5
0 is attached to the mold 60 so as to have a relationship as shown in FIG. As a mechanism for revolving the rotary blade 50, the rotary blade 50 revolves while making sure that the rotary blade 50 contacts the center axis of the product a while reliably contacting the rotary blade 50 with a constant cutting depth. If so, an appropriate mechanism can be used. For example, the mechanism described with reference to FIGS. 8 to 10 or a mechanism similar thereto can be used. The rotary blade 50 itself is rotatably attached to the mechanism. The rotation speed (revolution number) of the rotary blade 50 is preferably 30 to 120 rotations / minute. On the other hand, on the mold 60 side, the outlet 61A of the inner mold 61 is set so as to protrude slightly (about 2 to 5 mm) from the outlet 62A of the outer mold 62. Thereby, at the time of forming a cut, the tip of the rotary blade 50 and the end face of the inner mold are in a press-cut state as shown in FIG.

FIG. 5 is a conceptual diagram of forming a cut in the product a using the rotary blade 50. 5, 70 corresponds to the rotary blade main body 51 of FIG. 1, and 71 is the annular members 53 and 5 of FIG.
3, 72 indicates the formed groove. In other words, the rotary blade 50 can be considered as a molding die for forming the cut portion. As shown in FIG. 5 (a), the notch is formed by the rotary blade 50. First, as shown in FIG. 5 (a), a cut is made by the blade 70, and then the annular member (here, the angle between the outer peripheral surface and the rotary blade surface is 90 degrees). Reference numeral 71 denotes a forming ring, which proceeds while forming a groove 72 in the product a. As described above, the rotary blade 50 according to the present invention can perform the two steps of forming the groove and slicing as a series of one-step operations. As a result, it is possible to prevent the turning after the cutting and to form the cutting groove having a stable shape.

Next, the actual cut forming operation will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 4 shows that the rotary blade 50 is a product a.
3 (a) is a sectional view taken along line AA of FIG. 4, FIG. 3 (b) is a sectional view taken along line BB of FIG. 4, and FIG. 3 (c). FIG. 5 is a sectional view taken along line CC of FIG. 4. FIG.
As in the case of the above, the pellet-shaped thermoplastic resin as a raw material is supplied to the extruder, and a product a having a shape in which the vertical ribs c... And
This is forcibly pulled by a tension roller as in the case of FIG. Then, the rotating blade 50 is rotated at a predetermined rotation speed by a mechanism (not shown) for rotating the rotating blade 50. At this time, the relationship between the cutting edge portion 52 of the rotary blade 50 and the product a to be cut is as shown in FIGS. 3A to 3C. That is, when the tip of the cutting edge portion 52 is cut into the product a, as shown in FIG. 3A, the cutting edge comes into contact with the tip of the cutting edge portion 52, and when the rotation of the rotary blade 50 proceeds, as shown in FIG. As described above, the cutting edge portion 52 is cut into the surface of the product a, and when the rotation of the rotary blade 50 further proceeds, FIG.
As shown in (c), the cutting blade 50 and the outlet portion 61A of the inner mold 61 are in the state of being pushed off. Here, the notch is formed as if cutting while embossing with a press cutter, and a final product having a stable cut shape can be obtained.

In the above description, the lattice network is formed on the entire surface of the synthetic resin porous tube. However, according to the present invention, the lattice network can be partially formed. This can be performed by, for example, using a cam or the like to install the cutting edge of the rotary blade so as to be able to move forward and backward.

[0017]

According to the present invention, the following remarkable effects can be obtained. (1) Even when a resin that increases the internal pressure of an extrusion die is used as a raw material, a sharp-shaped helical cut does not occur and a product with a stable shape can be obtained. Therefore, a user-friendly product can be provided. (2) Two steps of forming and cutting grooves can be processed at once. (3) The cut surface can be formed by the outer peripheral shape of the annular member constituting the rotary blade. (4) The mesh pitch can be varied in various ways depending on the revolution speed of the rotary blade and the take-up speed of the take-up machine. (5) In the case of a well strainer in which a mesh-shaped product is connected to the tip of a pipe-shaped product by a socket, if the rotary blade has a structure that can be pulled in and out from the outside, the tip portion of the pipe-shaped product It is also possible to manufacture an integrated product in which only a mesh is formed.

[Brief description of the drawings]

FIGS. 1A and 1B are explanatory views of a rotary blade according to the present invention, wherein FIG. 1A is a perspective view showing a state of forming a cut, and FIG. 1B is a cross-sectional view taken along line AA of FIG.

FIG. 2 is an exploded perspective view of a rotary blade according to the present invention.

FIG. 3 is an explanatory view of the operation of the rotary blade according to the present invention.

FIG. 4 is a view showing a state where a rotary blade processes an outer peripheral surface of a product.

FIG. 5 is a view showing the principle of cutting the rotary blade according to the present invention.

FIG. 6 is a perspective view of a conventional synthetic resin porous tube.

FIG. 7 is an overall configuration diagram of an apparatus for manufacturing a synthetic resin porous tube previously proposed by the present applicant.

FIG. 8 is a side view of a cut forming mechanism of the apparatus of FIG. 7;

FIG. 9 is a rear view of the apparatus of FIG. 7;

FIG. 10 is an exploded perspective view of the device of FIG. 7;

FIG. 11 is a perspective view showing an example of a synthetic resin porous tube made by the apparatus shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 50 cutting blade 51 rotary blade main body 52 cutting edge portion 53 covering member 54 outer peripheral surface portion 55 unevenness 60 die 61 die inner die 61A inner die outlet portion 62 die outer die 62A outer die outlet portion

Claims (5)

[Claims] 1. A disk-shaped rotary blade main body having a central hole,
The rotary blade body is composed of a pair of annular members that sandwich the rotary blade body from both sides thereof, and each of the annular members has a smaller diameter than the rotary blade body,
The peripheral surface portion is formed on a tapered surface portion facing the rotary blade main body or a wall surface perpendicular to the rotary blade surface, and the tapered surface portion or the vertical wall surface portion is formed with irregularities over the entire circumference at regular intervals. A rotary blade characterized by the above. 2. The method according to claim 1, wherein said annular member is made of a metal material.
A rotary blade according to item 1. 3. A synthetic resin tube having a lattice-like mesh formed by forming spiral cuts on an outer peripheral surface of a synthetic resin tube having inner longitudinal ribs obtained by extrusion molding. Or 2 rotary blades. 4. The rotary blade according to claim 3 is rotatably disposed near an outlet of the extrusion mold and around a product to be fed, and the rotary blade itself is rotatably mounted.
Synthesizing characterized in that a groove is formed on the outer peripheral surface of the synthetic resin tube fed from the extrusion molding die by the annular member of the rotary blade, and a cut is formed by making a cut in the rotary blade body. A method for manufacturing a porous resin tube. 5. An extrusion mold inner mold exit portion is set so as to protrude slightly from the mold outer mold exit portion, and the rotary blade and the end surface of the mold inner mold are in a press-cut state. 5. The method for manufacturing a synthetic resin porous tube according to claim 4, wherein the cut is formed by cutting off the resin material as described above.