JP3708659B2 - Manufacturing method and apparatus for corrugated pipe made of synthetic resin - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a manufacturing method and a manufacturing apparatus for a synthetic resin corrugated pipe whose interior is partitioned into several storage cylinders by a partition wall.
[0002]
[Prior art]
Synthetic resin corrugated tubes have flexibility and pressure resistance, and are therefore used as distribution line pipelines for electric cables and the like. In order to manufacture such a synthetic resin corrugated tube, a tunnel-shaped movable molding space having a bellows-shaped inner peripheral surface is formed by an upper and lower mold formed by connecting a large number of divided molds in an endless manner. An uncured synthetic resin cylindrical body is supplied into the molding space from a nozzle disposed on the front end side of the movable molding space, and the synthetic resin cylindrical body is expanded by air pressure to be pressed against the bellows-shaped inner peripheral surface. Thus, a method for forming a bellows-shaped tube wall is widely known.
[0003]
[Problems to be solved by the invention]
However, in the method of manufacturing a synthetic resin corrugated pipe as described above, an uncured synthetic resin cylindrical body is supplied into a molding space from a single nozzle, and the cylindrical body is expanded to cover the entire peripheral wall. Since it is formed on the bellows-like tube wall having the same shape as the bellows-like inner peripheral surface by pressing the upper and lower bellows-like inner peripheral surface, only one distribution line storage space portion can be provided inside. Can not. Therefore, when storing transmission lines, optical cables, and other various distribution lines in a synthetic resin corrugated pipe obtained by such a method, all distribution lines must be stored in a lump. Since it is difficult to store the wires separately from the electric wires, there is a problem that, when performing maintenance and inspection, troubles such as troublesome work and maintenance work are required to confirm the target distribution wires.
[0004]
The present invention has been made in view of such problems, and an object of the present invention is to efficiently and accurately provide a synthetic resin corrugated pipe having an interior partitioned into several storage cylinders by a partition wall. It is to provide a method that can be manufactured, as well as an apparatus for carrying out this method.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a method of manufacturing a synthetic resin corrugated tube, comprising several nozzles toward a tunnel-shaped movable molding space having a bellows-like inner peripheral surface. An uncured synthetic resin cylindrical body is supplied and air is supplied to each synthetic resin cylindrical body to expand these synthetic resin cylindrical bodies by the air pressure, and the peripheral wall portion of each synthetic resin cylindrical body is caused by the expansion. Are pressed against the inner peripheral surface of the bellows to form a bellows-shaped tube wall along the inner peripheral surface of the bellows, and a part of the peripheral wall portion of the opposing synthetic resin cylindrical body is closely adhered to and integrated with each other A partition wall that divides the inside of the pipe into several storage cylinders over the entire length is formed.
[0006]
The invention according to claim 2 is an apparatus for carrying out the synthetic resin corrugated pipe manufacturing method according to claim 1 , wherein an upper mold that circulates by connecting a number of divided molds in an endless manner, and A tunnel-shaped formation space having a bellows-shaped inner peripheral surface is formed by opposing surfaces that are joined to the lower mold, and an uncured synthetic resin cylindrical body is formed on the front end side of the tunnel-shaped formation space toward the formation space. Several nozzles for supplying the air are faced, and air holes for supplying air for expanding the cylindrical body pushed out from each nozzle are provided in each nozzle.
[0007]
[Action and effect]
Claim 1 for producing a synthetic resin corrugated pipe as above reporting, according to the invention described in claim 2, several nozzles towards the tunnel-shaped moving mold space having a bellows-like inner surface Since uncured synthetic resin cylinders are supplied and each synthetic resin cylinder is expanded in the direction of diameter expansion by air, the peripheral walls of the synthetic resin cylinders facing each other due to the expansion move in a tunnel shape. The upper and lower bellows-shaped inner peripheral surfaces forming the molding space are in close contact with each other and integrated to form a partition wall, and at the same time other peripheral wall parts are pressed against the bellows-shaped inner peripheral surface to form a bellows-shaped tube wall In addition, a synthetic resin corrugated pipe whose interior is divided by the partition wall can be manufactured reliably and efficiently.
[0008]
Furthermore, it has a plurality of partition walls according to the number of nozzles by changing the number of nozzles facing the tunnel-shaped movable molding space, and a wire storage tube portion divided into a plurality of portions through the partition walls. A synthetic resin corrugated pipe can be manufactured, and the interior of the pipe is divided into a plurality of parts in the circumferential direction by a partition wall provided radially from the center to the outer circumference by arranging the upper and lower, right and left nozzles. A synthetic resin corrugated pipe having a simple storage cylinder can be easily manufactured.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
A specific embodiment of the present invention will be described with reference to the drawings. A synthetic resin corrugated pipe 1 shown in FIGS. 1 and 2 includes a tubular wall 2 having an annular ridge 2a and a circumferential groove 2b that are oblong in cross section. Having a bellows shape formed alternately and continuously in the length direction of the tube, and a vertical partition made of the same resin as the tube wall 2 on the inner surface of the tube wall 2 opposite to the center of the parallel upper and lower wall portions. The upper and lower ends of the wall 3 are integrally connected over the entire length, and the inside of the pipe is divided and formed into two distribution line storage cylinder portions 4a and 4b on the left and right over the entire length by the partition wall 3. .
[0010]
3 and 4 show a synthetic resin corrugated pipe 1A formed by dividing the inside of the pipe into three distribution line storage cylinders 4a, 4b, 4c in the left-right direction. The annular protrusion 2a and the circumferential groove 2b The cross-sectional shape of the bellows-shaped tube wall 2 formed by alternately and continuously forming the tube wall 2 is formed in an oblong shape that is further horizontally longer than the corrugated tube 1, and the upper and lower walls of the tube wall 2 are parallel to each other. The upper and lower ends of both vertical side partition walls 3a and 3b made of the same resin as the pipe wall 2 are integrally connected over the entire length on the inner surface facing the one side and the inner surface facing the other side. The inside of the pipe is divided and formed into three distribution line storage cylinders 4a, 4b, 4c of the center and both sides by walls 3a, 3b.
[0011]
FIG. 5 shows a synthetic resin corrugated pipe 1B formed by dividing the inside of the pipe into four distribution line storage cylinders 4a, 4b, 4c, and 4d in the vertical and horizontal directions. Annular ridges 2a and circumferential grooves 2b are formed alternately and continuously in the length direction, and are cross-sectioned from the center in the tube to the left and right inner surfaces and the upper and lower inner surfaces facing the diameter direction of the tube wall 2. The outer ends of the partition walls 3a, 3b, 3c, 3d extending in a cross shape are integrally connected over the entire length, and the partition walls 3a to 3d accommodate the four distribution lines in the upper, lower, left, and right sides. The cylindrical portions 4a to 4d are divided and formed.
[0012]
Next, the manufacturing method and apparatus for the synthetic resin corrugated pipes 1, 1 A, 1 B having the above-described structure will be described. FIG. 6 is a vertical side view showing the outline of the apparatus, and the arrangement of nozzles to be described later Except for the form, it is the same as a conventional so-called blow molding apparatus. In the figure, 5 and 6 are an upper die and a lower die formed by connecting a large number of block-shaped split dies 5a and 6a, respectively, and these upper and lower dies 5 and 6 are not shown between front and rear sprocket wheels (not shown). The end surfaces of the upper and lower molds 5 and 6 are circulated and moved in a state of being in close contact with each other by endlessly spanning them and rotationally driving the rear sprocket wheel.
[0013]
As shown in FIGS. 7 and 8, the upper half and the lower half of the bellows-shaped tube wall 2 are formed on the opposing surfaces of the split molds 5a and 6a constituting the upper and lower molds 5 and 6, respectively. A plurality of semi-annular ridges 5b and 6b and semi-circular circumferential grooves 5c and 6c are formed alternately in the length direction over the entire length. When the upper and lower molds 5 and 6 are circulated and moved, the upper and lower divided molds 6a and 6a coincide with each other in a circulation path in which the opposing surfaces of the plurality of upper and lower divided molds 5a and 6a move toward each other. The tunnel-shaped movable molding space 7 having the bellows-like inner peripheral surface is formed by the cross-sectional semi-annular ridges 5b and 6b and the circumferential grooves 5c and 6c.
[0014]
Further, the front end side of the movable molding space 7 faces the open ends of several nozzles that supply the semi-molten state, that is, the uncured synthetic resin cylindrical body 8 toward the movable molding space 7. Yes. In this case, in order to manufacture the corrugated tube 1 having the two wiring storage cylinders 4a and 4b shown in FIGS. 1 and 2, the movable molding space 7 having an oblong cross-sectional shape as shown in FIGS. The corrugated pipe 1A having three wiring housing cylinders 4a, 4b, 4c shown in FIGS. 3 and 4 is manufactured by arranging two nozzles 9a, 9b on the left and right sides with the open ends facing both sides of the tube. In this case, as shown in FIGS. 11 and 12, the three nozzles 9a to 9c are arranged with the open ends facing both side portions and the central portion in the movable molding space 7 having a horizontally long circular cross section.
[0015]
FIG. 6 shows only one of these nozzles (reference numeral 9), but each nozzle 9 is a hollow nozzle body that gradually narrows toward the tip (rear side in the figure). 10 is formed in the hollow end of the nozzle body 10, and a core 11 is arranged inside the hollow outer surface of the tapered end of the core 11 and the circular inner periphery of the tip of the nozzle body 10. A molding passage 12 having an annular cross section of the uncured synthetic resin cylindrical body 8 is formed between the surface and the surface. Further, the base end side of each molding passage 12 communicates with a passage 14 on the extruder (not shown) side through a resin passage 13 provided between the large-diameter base ends of the nozzle body 10 and the core 11. .
[0016]
In addition, air holes 15 are provided in the center of the core 11, and each air hole 15 moves from the center of each nozzle 9 through the center surrounded by each of the above-described formation passages 12 to the above-described moving molding. It faces the space 7 and the base end side communicates with an air supply pipe 16 outside the nozzle body 10.
[0017]
With the apparatus configured as described above, for example, the corrugated pipe 1 is manufactured, in which the interior shown in FIGS. 1 and 2 is formed in the left and right distribution line storage cylinder portions 4a and 4b by one partition wall 3. As described above, an uncured annular shape is formed from the resin passage 13 through the molding passage 12 using an apparatus having two nozzles 9a and 9b facing the movable molding space 7 having an oblong cross-sectional shape. Synthetic resin cylinders 8a and 8b are fed into the movable molding space 7 in synchronism with the cyclic movement speeds of the upper and lower molds 5 and 6 forming the movable molding space 7 from the tips of the nozzles 9a and 9b, respectively, and uncured that has been sent out. Air is supplied through the air holes 15 into the synthetic resin cylinders 8a and 8b.
[0018]
The insides of the synthetic resin cylindrical bodies 8a and 8b are closed by well-known means (not shown), for example, plugs (not shown) connected from the tip ends of the nozzles 9a and 9b via a filament. Therefore, the air blown out from the air holes 15 is filled in the respective synthetic resin cylindrical bodies 8a and 8b and the pressure rises, and the uncured synthetic resin cylindrical bodies 8a and 8b are expanded by the pressure, so that the upper and lower molds 5 and 6 are annularly joined to each other and are pressed against the circumferential groove portions 5b and 6b and the circumferential groove portions 5c and 6c, and are deformed along the shape of the protruding groove portions 5b and 6b and the circumferential groove portions 5c and 6c to form a bellows shape. At the same time, the opposite peripheral wall portions of the synthetic resin tubular bodies 8a and 8b expand toward the center of the movable molding space 7 without being pressed against the protrusions 5b and 6b and the circumferential grooves 5c and 6c. Then, the vertical partition wall 3a having a certain thickness is formed by being joined and integrated so as to overlap each other in the central portion, and passes through the movable molding space 7. When cured, the corrugated tube 1 is obtained by dividing the tube wall 2 having a horizontally long oval cross section shown in FIGS. 1 and 2 into the left and right distribution line storage cylinders 4a and 4b by the vertical partition wall 3. Can do.
[0019]
To manufacture the synthetic resin corrugated pipe 1A formed by dividing the inside of the pipe shown in FIGS. 3 and 4 into three distribution line storage cylinders 4a, 4b and 4c, as shown in FIGS. Using an apparatus in which nozzles 9a to 9c are arranged at both sides and a central portion in the movable molding space 7 having a cross-sectional oblong shape, uncured synthetic resin cylinders 8a to 8c are passed from these nozzles 9a to 9c. Left and right partition walls by feeding into the movable molding space 7 and inflating the cylindrical bodies 8a to 8c with air pressure supplied from the air holes 15 so that the peripheral wall portions of the cylindrical bodies facing left and right are pressed against and integrated with each other. The bellows-shaped tube is formed by forming 3a and 3b and pressing the other peripheral wall portion with the inner peripheral surface of the movable molding space 7, that is, the protruding portions 5b and 6b of the upper and lower molds 5 and 6 and the peripheral groove portions 5c and 6c. A corrugated pipe 1A that forms a wall 2 and is divided into three distribution line storage cylinders 4a, 4b, 4c by the left and right partition walls 3a, 3b. It is get those.
[0020]
Further, as shown in FIG. 5, in order to manufacture a synthetic resin corrugated pipe 1B having an annular cross-section formed by dividing the inside of the pipe into four distribution line storage cylinders 4a to 4d on the upper, lower, left and right sides, As split molds 5a and 6a forming molds 5 and 6, as shown in FIG. 13, a projecting part 5b having a semicircular cross section and a circumferential groove part 5c are continuously formed in the lengthwise direction on the opposing surface. The front end of the circular movable molding space 7 formed on the opposite surface by moving the upper and lower molds 5 and 6 formed by connecting a large number of these divided molds 5a and 6a in the same manner as described above. The nozzles 9a to 9d face the top, bottom, left, and right of the opening, and uncured synthetic resin cylinders 8a to 8d are fed into the movable molding space 7 from the nozzles 9a to 9d, and the center of each nozzle 9a to 9d Air is supplied into the cylindrical bodies 8a to 8d from the air holes 15 arranged in the section, and the cylindrical states 8a to 8d are expanded by the air pressure. By forming the upper and lower vertical partition walls 3a and 3b and the left and right horizontal partition walls 3c and 3d that are integrated in a cross shape by pressing and integrating the peripheral wall portions of the cylindrical body that are opposed to each other in the front and rear and left and right directions, The bellows-shaped tube wall 2 is formed by press-contacting the peripheral wall portion with the protrusions 5b and 6b on the inner peripheral surface of the movable molding space 7 and the peripheral groove portions 5c and 6c.
[0021]
In addition, this invention is not limited to the synthetic resin corrugated pipes 1-1B of the cross-sectional shape shown in the above Example, The protrusion formed in the opposing surface of the division | segmentation type | molds 5a and 6a which comprise the upper-and-lower type | molds 5 and 6 Depending on the cross-sectional shape of the strips 5b, 6b and the circumferential groove portions 5c, 6c, the arrangement of the nozzles, the number of nozzles, etc., the inside of the tube is divided into several distribution line storage cylinders with a partition wall, and has various cross-sectional shapes A synthetic resin corrugated tube can be manufactured.
[0022]
For example, by making three nozzles 9a to 9c face as shown in FIG. 14 in a circular movable molding space 7 formed by the upper and lower molds 5 and 6 shown in FIG. 13, as shown in FIG. A synthetic resin corrugated pipe having three distribution line storage cylinder portions 4a to 4c partitioned by three partition walls 3 provided radially from the center toward the pipe wall from the center can be manufactured. As the split molds 5a and 6a of the upper and lower molds 5 and 6, those having a quadrilateral section and a circumferential groove formed continuously in the length direction on the opposing surface are used, and nozzles are arranged vertically and horizontally. As a result, a synthetic resin corrugated pipe having a rectangular cross section is obtained by dividing and forming the distribution line storage cylinders 4a to 4d having a rectangular cross section in the vertical and horizontal directions by the cross-shaped partition wall 3 as shown in FIG. be able to.
[0023]
Further, as the split molds 5a and 6a of the upper and lower molds 5 and 6, the cross-sectional shape of the projecting ridge portion and the circumferential groove portion of the opposing surfaces is formed in a double arch shape and the nozzles are arranged on the left and right sides. A synthetic resin corrugated tube having a cross-sectional glasses shape having a partition wall 3 at the center as shown in FIGS. 17 and 18 can be manufactured. Further, as the split molds 5a and 6a of the upper and lower molds 5 and 6, the cross-sectional shape of the projecting ridge portion and the circumferential groove portion of the opposing surface is formed in three or more arch shapes, and the distribution line storage cylinder portions are integrally arranged in a plurality of rows. A synthetic resin corrugated pipe arranged side by side can also be manufactured.
[Brief description of the drawings]
FIG. 1 is a longitudinal front view of a corrugated pipe obtained by dividing the inside of a pipe into two storage cylinders,
FIG. 2 is a plan view showing a part of the cross section;
FIG. 3 is a longitudinal front view of a corrugated pipe obtained by dividing the inside of the pipe into three storage cylinders;
FIG. 4 is a cross-sectional plan view of a part thereof,
FIG. 5 is a longitudinal front view of a corrugated pipe formed by dividing the inside of the pipe into four storage cylinders;
FIG. 6 is a simplified longitudinal side view showing a corrugated tube manufacturing apparatus;
FIG. 7 is a plan view of protrusions and circumferential grooves provided in the upper and lower split molds;
FIG. 8 is a front view of the state where the upper and lower divided types are combined,
FIG. 9 is a longitudinal sectional view showing a state in which two nozzles face the movable molding space;
FIG. 10 is a cross-sectional view showing a molded state,
FIG. 11 is a longitudinal sectional view showing three nozzles facing the movable molding space;
FIG. 12 is a cross-sectional view showing a molding state;
FIG. 13 is a longitudinal sectional view showing four nozzles facing the movable molding space;
FIG. 14 is a longitudinal sectional view showing another example of a state in which three nozzles face the movable molding space;
FIG. 15 is a longitudinal sectional view of a molded corrugated pipe,
FIG. 16 is a longitudinal sectional view of another shape corrugated pipe having storage cylinders on the top, bottom, left and right;
FIG. 17 is a longitudinal front view of a corrugated pipe having another shape obtained by dividing the inside of the pipe into two storage cylinders;
FIG. 18 is a longitudinal front view of a corrugated pipe having yet another shape obtained by dividing the inside of the pipe into two storage cylinders.
[Explanation of symbols]
1 Corrugated pipe 2 Pipe wall 3 Partition wall
4a to 4d Distribution line storage cylinder 5, 6 Vertical type
5a, 6a split type
5b, 6b Projection
5c, 6c Circumferential groove 7 Moving molding space 8 Synthetic resin tubular body 9 Nozzle
15 Air hole

Claims (2)

  An uncured synthetic resin cylindrical body is supplied from several nozzles into a tunnel-shaped movable molding space having a bellows-shaped inner peripheral surface, and air is supplied to each synthetic resin cylindrical body by the air pressure. The synthetic resin cylindrical body is inflated, and by the expansion, the peripheral wall portion of each synthetic resin cylindrical body is pressed against the bellows-shaped inner peripheral surface to form a bellows-shaped tube wall along the bellows-shaped inner peripheral surface. A part of the peripheral wall portion of the opposing synthetic resin cylindrical body is closely attached to each other and integrated to form a partition wall that divides the inside of the pipe into several storage cylinder portions over the entire length. A method for manufacturing a corrugated tube.   A tunnel-shaped formation space having a bellows-shaped inner peripheral surface is formed by facing surfaces of the upper mold and the lower mold that are circulated by connecting a plurality of divided molds endlessly, and this tunnel-shaped formation space A plurality of nozzles for supplying an uncured synthetic resin cylindrical body toward the formation space on the front end side of the nozzle, and for expanding the cylindrical body extruded from each nozzle into each nozzle An apparatus for producing a corrugated pipe made of synthetic resin, characterized in that an air hole for supplying air is provided.

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