JPH0531364B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a method of manufacturing a wiring duct, and more specifically, to a method of manufacturing a wiring duct by a plastic injection molding method.

<Prior art> As shown in Fig. 5, a wiring duct has electric wire outlet ports 4...4 on both side walls 2, 3 of the bottom surface 1 of a long gutter-like body.
are continuously perforated, and a lid 7 is provided at the upper edge of both side walls 2 and 3.
Fitting portions 8 and 9 are formed for fitting with the two side walls 2 and 3, and these fitting portions 8 and 9 have portions that extend inward from the extension surfaces of the side walls 2 and 3. When the body is in use and fitted with the lid 7, both side walls 2 and 3 are parallel to each other, but when they are not fitted, the upper edges are shaped to widen slightly in order to generate a frictional force for fitting. .

The conventional manufacturing method for such wiring ducts is
After molding the entire body using extrusion molding method, wire outlet 4...
4 was punched out using a press.

In response to this, the present inventor has separately proposed a method for manufacturing a long wiring duct using a novel plastic injection molding method.

<Problems to be Solved by the Invention> According to this prior invention, since the next injection molding is performed with the injection molded product displaced in the longitudinal direction of the duct, the end face of the previous molded product and the newly injected A problem arises in joining with the molten resin.

An object of the present invention is to provide a manufacturing method that strengthens the bond between a molded resin and a molten resin using simple means.

<Means for Solving the Problems> The manufacturing method of the present invention has a long gutter shape in which left and right side walls rise from both sides of the bottom plate and a fitting portion is formed on the upper edge of the side walls. In an injection molding method for a wiring duct in which a wire outlet is formed in the side wall, a mold for the side surface is used to mold both the inner and outer surfaces of the bottom plate and the left and right side walls, and a mold for the end surface is used to suppress one end surface in the longitudinal direction of the duct. After injection molding, a mold device is equipped with a mold, and the molding surface of the duct end face of the end face mold is formed with an uneven part including surfaces parallel to the bottom plate and the surfaces of the left and right side walls. , the side surface mold is released, then only the molded body is displaced in the longitudinal direction, and then the side surface mold is set to the state before release and the next injection molding is performed. It is characterized by manufacturing a continuous molded body through a series of steps.

This means that an uneven portion is formed that includes surfaces parallel to the bottom plate and the left and right side walls of the duct body.
As shown in Fig. 4a, when a convex portion 34 is provided at the center in the thickness direction, and surfaces 35 and 36 parallel to the duct surface are formed on both sides of the convex portion, as shown in Fig. 4b, It has a recess 37 in the center in the thickness direction,
Surfaces 38, 3 parallel to the duct surface on both sides of the recess
9 is formed, as shown in figure c, the duct has a convex part 40 on the inner surface side, and a surface 41 parallel to the duct surface is formed on the outside of the convex part, as shown in figure d of the figure. As shown in FIG.
3 may be formed.

<Effect> The operation will be described with reference to FIG.

First, on the rear end face side of the molded resin (duct) 33 in the moving direction, the tip part 32 of the end face mold 31 is placed.
For example, a concave portion is formed, and with the rear end of the molded resin 33 held in the side molds 11 and 14, the rear end surface of the molded resin 33 and the tip 32 of the end mold When molded resin is press-fitted in a high-temperature molten state into the space formed between Then, the rear end surface is melted, thereby joining the rear end of the molded resin 33 and the tip of the new molded resin.

The joint has a structure in which a convex shape is fitted into a concave shape, and the joint area is larger than that in the case of simply joining flat end surfaces, improving the strength of this joint portion.

Furthermore, by creating the above-mentioned fitting structure for the joint, the strength against loads acting in a direction perpendicular to the longitudinal direction of the long molded product is improved, making it difficult for the long molded product to bend. Become.

<Example> FIG. 1 shows a cross-sectional view of a mold apparatus used for carrying out the method of the present invention.

The mold is assembled in an inverted position with the bottom 1 of the duct body facing upward, and an injection port (not shown) is provided on the top surface of the bottom 1. The outer surface of the bottom of the first mold 11 is
A mold 12 molds the outer surface of one side wall, a third mold 13 molds the outer surface of the other side wall, a fourth mold 14 molds a part of the bottom inner surface of the inner surface of the one side wall, and a fifth mold 14 molds a part of the bottom surface of the inner surface of the one side wall. A mold 15 molds the inner surface of the other side wall and part of the bottom inner surface. The fourth and fifth molds 14 and 15 are located above the inside of the duct (first
Projections 21 and 22 extending outward from the bottom (in the figure) to the left and right are integrally formed, and the projections 21 and 2
A long hole 23, 2 having a long diameter in the protruding direction is provided at the base of 2.
4 is formed, and fixed shafts 17 and 18 are inserted through the elongated holes and supported with a degree of freedom. Also,
These protrusions 21 and 22 are connected to the compression spring 1 at the tip.
9 and 20 are provided to press the protrusions 21 and 22 toward the center, and compression springs 25 and 26 are provided below the tips of the protrusions 21 and 22 to press the mold on the inner surface of the duct side wall. A pressing force is applied in the direction of releasing the mold. In order to allow rotation of the fourth and fifth molds 14 and 15, a relief 2 is provided between the second and third molds.
7 and 28 are formed. The sixth mold 16 has a wedge shape that penetrates between the fourth and fifth molds 14 and 15.
The overlapping of the mold and the sixth mold defines the distance between the inner surfaces of the left and right side walls of the duct.

FIG. 2 shows the mold release state of this mold device.

The first mold 11 is displaced upward, and the second and third molds 12 and 13 are displaced laterally and outwardly to release the mold. 6th
When the mold of the fourth and fifth molds retreats significantly downward, the fourth and fifth molds
A space is created between the molds 14 and 15, and the compression spring 1
The molds 14 and 15 are formed into the elongated hole 2 by the pressing force of 9 and 20.
3, 24 are displaced toward the center within the allowable range,
Further, the pressing force of the compression springs 25 and 26 causes the tips 29 and 30 forming the bottom surface of the duct to rotate about the shafts 17 and 18, which serve as fulcrums, until they come into contact and are released from the inner surface of the duct.

FIG. 3 is a longitudinal cross-sectional view of the seventh mold for molding one end surface in the longitudinal direction of the duct (A-A cross section in FIG. 1).
shows. The tip 32 of the seventh mold 31 has the same cross-sectional shape as the duct body to be molded.

Now, in this Fig. 3, 33 is the molded resin (duct) that was molded earlier, and the rear end is the 7th part.
Since it was molded with the tip 32 of the mold 31,
The cross-sectional shape is concave as shown in the figure.
Further, after molding, the molded resin 33 is translated in parallel to a position where its rear end remains within the molds 11 and 14, and in this state, the rear end surface of the molded resin 33 and the tip 32 of the seventh mold The next injection molding resin is press-fitted in a high temperature molten state into the space formed between the two. As a result, the space is filled with resin to form a duct, and along with this, the molded resin 33
The inside of the concave shape at the rear end is also filled with molten resin, and the rear end of the molded resin 33 and the tip of the new molded resin are integrated. At this time, the same concave shape as before is formed at the tip of the new molded resin, and the new molded resin is moved to a position where the tip remains in the molds 11 and 14 in the same way as before. Then, by repeating the same steps one after another, a long wiring duct is obtained.

FIG. 4a shows an enlarged view of the molding surface of the duct end surface of the tip portion 32. It has a protrusion 34 at the center in the thickness direction, and surfaces 35 and 36 parallel to the longitudinal surface of the duct are formed on both the inner and outer surfaces of the protrusion 34. The optimal values for the thickness X of the convex portion 34 and the depth Y of the convex portion are determined by the thickness t of the duct, the material of the resin, etc.
It is sufficient that the required molten resin has enough heat capacity to melt the surface layer of the molded resin.

Figures 4b, 4c and 4d show modified examples of the molding surface of the duct end face. In each figure, 38, 39, 4
1 and 43 represent planes parallel to the longitudinal surface of the duct.

<Effects of the Invention> According to the present invention, it is possible to manufacture a continuous long wiring duct by repeating injection molding, and at that time, the boundary between the molded part and the new molded part is integrated by melt joining. Moreover, the joint portion can be made into a highly strong structure in which a convex shape is fitted into a concave shape, thereby making it possible to obtain a strong long wiring duct.

Further, according to the present invention, after injection molding one molded object, in a state where the side mold is released (opened),
Since only the molded body is moved in the longitudinal direction, the side mold only needs to be moved when the mold is opened during a series of molding cycles, and there is no need to move the molded body, for example, to feed the molded body, minimizing the molding cycle. As a result of being able to shorten the length, production efficiency can be improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the molding state of the mold device used for carrying out the present invention, FIG. 2 is a cross-sectional view showing the molding state of the mold device shown in FIG. 1, and FIG. , FIG. 4A is an enlarged view of section B in FIG. 3, and FIGS. 4B, C, and D are enlarged views showing modified embodiments of FIG. 4A. , FIG. 5 is a perspective view showing an example of a wiring duct manufactured by the method of the present invention. 1... Bottom plate, 2, 3... Side wall, 11, 12, 1
3, 14, 15... Mold for side surface, 31... Mold for end surface, 35, 36, 38, 39, 41, 43...
plane parallel to the longitudinal surface of the duct, 34, 37,
40, 42...Uneven portion.

Claims (1)

[Scope of Claims] 1 Wiring in which left and right side walls rise from both sides of a bottom plate and have a long gutter shape with a fitting part formed at the upper edge of the side walls, and a wire outlet is formed in the left and right side walls. A method for injection molding a duct for use in a duct, comprising a side mold for molding both the inner and outer surfaces of the bottom plate and left and right side walls, and an end mold for suppressing one end face in the longitudinal direction of the duct; After injection molding, the side mold is released from the mold using a mold device in which the molding surface of the duct end face of the mold has an uneven part including surfaces parallel to the bottom plate and the surfaces of the left and right side walls. , then displacing only the molded body in the longitudinal direction,
Manufacturing of a wiring duct, characterized in that a continuous molded body is manufactured by the following steps: after that, the mold for the side surface is set to a state before mold release and the next injection molding is performed. Method. 2. The side surface mold includes a first mold for molding the outer surface of the bottom surface, second and third molds for molding the outer surfaces of the left and right side walls, and the left and right side walls. A mold for molding the inner surface of the side wall, in which the upper edge of the side wall is integrally formed with left and right protrusions extending from above to the left and right outwards, and fourth and fifth molds having fulcrums at the roots of the protrusions. The method for manufacturing a wiring duct according to claim 1, comprising a mold and a sixth mold that penetrates between the fourth and fifth molds and is displaced in the vertical direction of the duct. .