JPH0139331B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for producing a synthetic resin-coated elongated body, and in particular, a device for producing a synthetic resin-coated elongated body, in which a plurality of protrusions extending in a specific direction are formed on the surface of the elongated body, and the protrusions are crushed under specific conditions. By forming a concave portion, it is possible to securely bind strings, etc., even with a small number of protrusions.
The present invention also provides an apparatus for manufacturing a synthetic resin-coated elongated body that ensures the wrapping of vines.

Synthetic resin-coated elongated bodies have recently been used in large quantities as, for example, agricultural and horticultural supports (or artificial bamboo), building materials, etc., but in particular, as agricultural and horticultural supports, it is difficult to form a large number of protrusions on the surface. It is known that the binding properties of strings and the like and the wrapping of climbing plants are improved.

For example, in the agricultural and horticultural support pole disclosed in Japanese Patent Publication No. 50-28325, a plurality of protrusions parallel to the longitudinal direction are formed at equal intervals on the synthetic resin layer, and the protrusions are further provided at regular intervals. A concave portion is formed on the surface.
However, since these concave portions are provided side by side in the circumferential direction for each protrusion, there is a problem in that the locations (height positions) where strings and the like can be tied are restricted. In addition, when the length of contact of the string with the support body is short, there is a problem that if the number of protrusions is small, the string may easily slip down depending on the position of the support.

On the other hand, in the synthetic resin-coated elongated body disclosed in JP-A No. 53-60977, the protrusions are arranged in a plurality of rows parallel to the longitudinal direction at equal intervals and are staggered so that they are not arranged in the circumferential direction. Therefore, the problem of being limited in the locations where the strings and the like can be tied is almost eliminated. However, the problem that the strings tend to slip when the number of rows is reduced could not be solved.

This invention has been made in view of these circumstances, and its specific configuration is that a synthetic resin coating layer is formed on the outer periphery of the elongated body, and the coating layer has a spiral shape along the longitudinal direction of the elongated body. Forming multiple protrusions,
and an apparatus for producing a synthetic resin-coated elongated body, wherein the protrusions are provided with recesses formed by crushing and hardening the protrusions at approximately equal intervals while the synthetic resin coating layer is still in a softened state, the apparatus comprising: The head die is rotatably mounted coaxially with respect to the crosshead die main body, and has a plurality of grooves on the molten synthetic resin passage forming surface in substantially the same direction as the passage, and has a plurality of grooves in the longitudinal direction of the elongated body. It consists of a crosshead die tip that can form a plurality of spiral protrusions on the synthetic resin coating layer along the crosshead die, a connecting body is attached to the crosshead die tip, and a connecting body is attached to the crosshead die tip. , has the shape of a rotating disk and has teeth of the same shape at regular intervals on its outer peripheral surface, and rotates in contact with the spiral protrusions formed on the synthetic resin coating layer, so that the synthetic resin coating layer is still in a softened state. This is an apparatus for producing a synthetic resin-coated elongated body, in which a number of freely rotatable bodies, the same in number as the number of protrusions, are pivotally supported between which the spiral protrusions can be compressed at approximately equal intervals to form concave portions.

That is, the present invention is capable of rotatably attaching the tip of a crosshead die to the main body (fixed) of the crosshead die, and pivotally supporting a specific free rotating body to the tip of the crosshead die via a connecting body. Therefore, a concave portion can be formed in a spiral protrusion by rotating only the tip of the crosshead die without rotating and feeding a long body, thereby reducing the number of sliding parts that come into contact with high-pressure molten resin. to facilitate sealing.

The present invention will be described in detail below based on embodiments shown in the figures.

First, in FIGS. 1 to 3, a synthetic resin-coated elongated body 1 is mainly composed of an elongated body 2 made of a thin-walled steel pipe and a synthetic resin coating layer 3 formed on the outer periphery thereof.

This synthetic resin coating layer 3 has four protrusions 4, 5 spirally spaced at equal intervals in the longitudinal direction on its surface.
6, 7, and these protrusions further include recessed portions 8, 9..., 10, which are hardened by crushing each protrusion at approximately equal intervals while the synthetic resin coating layer is still in a softened state.
It is equipped with 11... Note that the depths of these recesses are set so that their bottom surfaces approximately correspond to the surfaces of the synthetic resin coating layer not provided with protrusions, such as 12 and 13. In addition, the position of the concave portion of each protrusion is set so as not to coincide with the circumferential direction of the synthetic resin-coated elongated body. Similarly, the positions of the strip portions (for example, 14, 15, 16) do not coincide with the circumferential direction of the elongated body.

The synthetic resin-coated elongated body 1 configured as described above is
For example, it is used as a support for agriculture and horticulture, and since the recesses 8, 9..., 10, 11... are formed on the surface, when used as a support for vine plants,
As the vines grow, they are supported by the recesses, so they do not easily fall off, which is preferable.

Furthermore, when tying with a string or the like, there is no need to select a location for tying because the concave portion exists at an arbitrary height position, and furthermore, the tying can be done reliably without the string moving up or down.

Furthermore, even when the length of the string in contact with the copper surface of the elongated object 1 is short, such as when the synthetic resin-coated elongated object 1 is tied to a thick rod-like object with a string, the protrusions are spiral. By selecting the binding height position of the string, it is possible to always find protrusions (for example, 14 and 16) that can prevent the string from shifting vertically.

Next, an apparatus for manufacturing the synthetic resin-coated elongated body 1 and a manufacturing method using the apparatus will be explained in order.

5 and 6, a crosshead die 21 of an apparatus 20 for manufacturing a synthetic resin-coated elongated body includes an elongated body insertion passage 22 and a molten synthetic resin passage 23. Further, the tip end 24 of the die 21 has a plurality of grooves 25 and 26 carved in the inner circumferential wall of the tip, that is, the molten synthetic resin passage forming surface in substantially the same direction as the passage, and is coaxial with the crosshead die body 29. It is rotatably mounted. 30 is a sprocket wheel as a means for supplying rotational force to the die tip 24, 31 is a sprocket on the motor side, and 32 is a chain.
Next, this sprocket wheel 30 has a connecting board 5.
8, 59 and connecting bodies 33, 34..., the recess forming means 37, 38 are integrally connected. That is, the concave portion forming means 37 is a free rotating body 42 having the same shape and provided with tooth profiles 46 at regular intervals.
As will be described later, the tooth profile is appropriately arranged so as to rotate in contact with the protrusion of the synthetic resin layer formed by the grooves 25, 26, . . . In addition, 50
is a support member coupled to the connecting body 33, and 51 is a shaft.

Next, a method of manufacturing the synthetic resin-coated elongated body 1 using the apparatus 20 having the above mechanism will be explained.

In FIG. 4, P is a long body made of a thin-walled steel pipe (a hollow or solid long body made of metal such as iron, steel and aluminum, or wood can be used). E is a polyvinyl chloride resin that covers the outer wall of the elongated body P. (Usually polyethylene, polyvinyl chloride, polypropylene, polyamide, ethylene-vinyl acetate copolymer, ABS resin, etc. are used).

The elongate body P is continuously inserted into the elongate body insertion passage 22, and on the other hand, molten synthetic resin E is fed from an extruder (not shown) to the molten synthetic resin passage 23, and melted onto the outer periphery of the elongate body P. Synthetic resin E is extrusion coated. At this time, when the mold attached to the crosshead die main body 29, that is, the tip 24, is rotated, the filamentous molten resin discharged from the grooves 25, 26, etc. carved in the inner circumferential wall of the mold 24 swirls. Meanwhile, spiral protrusions 4, 5... are formed along the longitudinal direction on the synthetic resin coating layer of the elongated body P.
...and is formed integrally.

Next, this synthetic resin-coated elongated body 1 is sequentially formed into recesses 8, 9 while the molten resin is still in a softened state by crushing the protrusions 4, 5, etc. using a recess forming means integrally connected to the mold 24. ...to form. Note that the concave portion forming means is provided by attaching the connecting body 3 to the mold 24.
3, 34, . . . so that it rotates integrally with the mold 24 in the axial direction of the elongated body and always moves following each protrusion. On the other hand, the synthetic resin-coated elongated body 1 includes a plurality of opposing rotating bodies 42 and 43 constituting the recess forming means.
It passes through the space surrounded by ... and is collected by a collection machine (not shown). Although these rotating bodies 42, 43... do not have a driving means, the tooth profile of the rotating body, for example, the tooth profile 46 of the rotating body 42, presses the respective protrusions 4, 5..., so that the rotating body 42 protrudes. A rotational force corresponding to the speed of rolling on the strip 4 is induced. Of course, since each protrusion corresponds to each of the rotating bodies 42, a concave portion is formed in each protrusion using the tooth profile 46. At this time, the position of the tooth profile of each rotary body is determined in advance on the elongated body. By shifting the protrusions slightly in the axial direction (the tooth profiles of each rotating body do not press simultaneously in the circumferential direction of the elongated body), each protrusion is formed so that recesses are not located at adjacent positions in the circumferential direction. be able to.

In this way, each of the rotating bodies 42, 43, . . . does not have a driving means and can rotate independently, so the device is simple and the operation is extremely easy.

It should be noted that various shapes can be easily obtained by changing the rotating state of the protrusions by changing the rotational speed of the mold 24, and by replacing the pitch of the concave portion with a rotating body having a different tooth profile pitch.

The synthetic resin-coated elongated body differs from Figs. 1 to 3,
As shown in FIGS. 6 and 7, the concave portions 8a and 9a are formed with low tooth profiles having ridges or valleys in the circumferential direction, thereby making it possible to more reliably prevent strings from slipping. Further, as shown in FIG. 8, the recesses 8b and 9b can be formed shallowly. Furthermore, the protrusion 14c formed by forming the concave portions 8c, 9c on the protrusion can be formed into an elliptical shape as shown in FIG. 9.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an elongated body obtained by the apparatus for producing a synthetic resin-coated elongated body according to the present invention, and FIG.
3 is an enlarged view of the vicinity of the protrusion 14 in FIG. A side view seen from the extrusion side, FIG. 6 is a view corresponding to FIG. 2 showing another example of a synthetic resin-coated elongated body, and FIG.
The figure is a diagram corresponding to FIG. 3, and each of FIGS. 8 to 9 is a diagram corresponding to FIG. 3 showing still other examples. 1...Synthetic resin coated elongated body, 2...Elongated body, 3
...Synthetic resin coating layer, 4, 5... Protrusion, 8, 9...
...concavity.

Claims (1)

[Scope of Claims] 1. An apparatus for manufacturing a synthetic resin-coated elongated body, which coats the elongated body with synthetic resin using a crosshead die having an elongate body insertion passage and a molten synthetic resin passage, comprising: a crosshead die; is rotatably mounted coaxially with the crosshead die main body, and has a plurality of grooves on the molten synthetic resin passage forming surface in approximately the same direction as the passages, and extends along the longitudinal direction of the elongated body. and a crosshead die tip that can form a plurality of spiral protrusions on the synthetic resin coating layer, and a connecting body is attached to the crosshead die tip, and this connecting body further has a rotating body. It is disc-shaped and has teeth of the same shape at regular intervals on its outer circumferential surface, and rotates in contact with the spiral protrusions formed on the synthetic resin coating layer while the synthetic resin coating layer is still in a softened state. An apparatus for manufacturing a synthetic resin-coated elongated body, in which the same number of freely rotating bodies as the number of spiral protrusions are pivotally supported, each of which is capable of crushing each spiral protrusion at approximately equal intervals to form concave portions.