JP2008201009A - Molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem in the prior art that when a cutting surface of a cutter is inclined at 60 degrees to the cross-sectional surface vertical to an intake direction of an intake opening in case of removing a disposal bag of an intake pipe made by blow-molding a thermoplastic resin, since the cut cross-sectional width becomes twice as large as the cut cross-sectional width in cutting vertically to the intake direction and then the cutting resistance becomes twice as large as the cutting resistance in cutting vertically, the intake pipe and the cutter are deformed and it is impossible to obtain a desired cut shape. <P>SOLUTION: A step facing outward of the intake pipe is mounted on the disposal bag at the cutting position of the cut surface where the cut surface of the disposal bag is inclined to the cross-sectional surface vertical to the intake pipe. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention is formed by blow molding of a thermoplastic resin and has a shape suitable for removing the discarded bag at the cut surface where the cut surface of the discarded bag is inclined with respect to a cross section perpendicular to the molded body. It relates to a molded body.

As a prior art regarding the removal of the discarded bag, there is one disclosed in Patent Document 1.
JP-A-6-91589

That is, paragraph No. 0005 of Patent Document 1 indicates that “a blade made of a flat rectangular steel plate is pressed against an extruded product, the pressing force is kept constant, and the blade is subjected to slight vibration to plastically cut the extruded product”. This method can be applied to the removal of the discarded bag as it is.

However, since it is “pressing a blade made of a flat rectangular steel plate”, there is no problem with a thin-walled cross-section, but when cutting a thick-walled cross-section, the cutting line will sway due to excessive cutting resistance. Therefore, there was a drawback that it could not be cut accurately.

Hereinafter, it will be described in more detail with reference to the drawings. FIG. 1 is a perspective view of an automobile intake pipe 1 formed by blow molding of a thermoplastic resin. 2 is a suction port, 3 is a discharge port.

FIG. 2 is a perspective view of the intake pipe 1 with a discarded bag immediately after blow molding. FIG. 3 shows a BB cross section of FIG. The waste bags 5 and 6 are removed by the plastic cutting of the prior art, but the suction port 2 is flat and inclined as shown in FIG. 1, and the cutter 7 is moved in the direction of arrow A as shown in FIG. When the waste bag 5 is removed and the suction port 2 is processed, the cut surface 8 of the blade 7 is inclined by 60 degrees with respect to the cross section perpendicular to the suction direction S of the suction port 2 as shown in FIG. Therefore, the inclined cut cross-sectional width b is doubled compared to the vertical cut cross-sectional width a when cutting perpendicularly to the suction direction S.

Therefore, there is a problem that the cutting resistance is twice that in the case of cutting vertically, and the intake pipe 1 and the blade 7 are deformed by the cutting resistance, so that they cannot be cut into the intended shape.

The problem to be solved is that when removing a bag of an automobile intake pipe formed by blow molding of a thermoplastic resin, the cut surface of the blade is inclined by 60 degrees with respect to a cross section perpendicular to the suction direction of the suction port. In this case, since the inclined cutting cross-sectional width is doubled compared to the vertical cutting cross-sectional width when cutting perpendicularly to the suction direction, the cutting resistance is also twice that when cutting perpendicularly. This is that the intake pipe and the blade cannot be cut into the intended shape due to deformation. The present invention has been made to solve the above-described points.

In order to achieve the above object, the present invention provides a molded body formed by blow molding of a thermoplastic resin, wherein the cut surface of the cut surface is inclined with respect to the cross section perpendicular to the molded body. Thus, the most important feature is that the waste bag has an outward step with respect to the molded body.

A second main feature is that the stepped portion cutting width at the cutting position is not more than two-thirds of the vertical cutting section width.

A third main feature is that the molded body is an intake pipe.

According to the present invention, since an outward step is provided with respect to the intake pipe at the cutting position of the discard bag, the parison is stretched while being bent sharply at the cutting position. The cut width of the stepped portion is very small and the cutting resistance is small, so when removing the bag and processing the suction port, the intake pipe and blade are not deformed and cut smoothly into the intended shape. There is an advantage that you can.

The cutting position of the cut surface where the cut surface of the bag is inclined with respect to the cross section perpendicular to the intake pipe for the purpose of removing the bag without deforming the intake pipe or the blade and processing the suction port. Thus, by providing an outward step with respect to the intake pipe in the disposal bag, an inexpensive construction method called plastic cutting was used, and the economic efficiency was not impaired.

The configuration of the present invention will be described based on the embodiments of the invention as follows. In addition, the same code | symbol as a prior art example represents the same member.

FIG. 4 is a sectional view of the suction port 2 showing an embodiment of the present invention. The disposal bag 5 is provided with a step h outwardly with respect to the intake pipe 1 at the cutting position P. Here, “outward” means a direction from the inside to the outside of the intake pipe 1.

Next, the operation of the present invention will be described. A semi-molten thermoplastic resin parison (not shown) such as polypropylene is suspended in a split mold (not shown), and the split mold is clamped.

The thermoplastic resin applied to the parison is not limited to polypropylene, but polyethylene, other polyolefin resins, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyamide resins, and polyacetal resins. Syndiotactic polystyrene, polystyrene, rubber-modified polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, modified polyphenylene oxide, polyphenylene sulfide, polycarbonate, etc. . Further, a composite material obtained by kneading glass fiber, carbon fiber, boron fiber, calcium sulfate powder, calcium carbonate powder, or the like with the thermoplastic resin may be used.

Thereafter, compressed air is blown into the parison and blown up to complete blow molding.

At this time, since the parison is stretched while being bent sharply at the cutting position P, the stepped portion cutting width t at the cutting position P is very small and the cutting resistance is small, so the discard bag 5 is removed. Thus, when the suction port 2 is processed, the intake pipe 1 and the blade 7 are not deformed and can be smoothly cut into the intended shape.

FIG. 5 shows a cross section of the suction port 2 after the discard bag 5 is cut. The stepped portion cutting width t is less than or equal to two-thirds of the vertical cutting section width a. That is,
Stepped portion cut width t ≦ (2/3) × vertical cut section width a
= (2/3) × (1/2) × the inclined section width b
= (1/3) × the inclined cut section width b
Therefore, the cutting resistance is 1/3 or less of the conventional example.

As described in the above embodiments, according to the present invention, since the outward step with respect to the intake pipe is attached at the cutting position of the discard bag, the parison is stretched while being bent sharply at the cutting position. Since the stepped portion cutting width at the cutting position is very small and the cutting resistance is small, when removing the bag and processing the suction port, the intake pipe and the blade are not deformed, There is an effect that it can be smoothly cut into the intended shape.

In the above embodiment, the intake pipe has been described as an example, but a molded body formed by blow molding of thermoplastic resin (corresponding to the intake pipe with a discarded bag) is removed from the molded body. As long as the remaining part is a molded body (corresponding to the intake pipe), any part can be used as long as the cut surface of the waste bag is inclined with respect to the cross section perpendicular to the molded body. The same effect can be obtained if the bag is configured to have an outward step with respect to the molded body.

The present invention can be used for an intake pipe for automobiles by blow molding made of a thermoplastic resin, but is not limited to this, and the cut surface of the discarded bag of the molded body by blow molding is a cross section perpendicular to the molding body. Widely available when tilted.

A perspective view of a conventional intake pipe A perspective view of a conventional intake pipe immediately after blow molding BB sectional view of FIG. Sectional drawing of the inlet of the intake pipe which concerns on this invention Sectional drawing after cutting | disconnection of the inlet of the intake pipe which concerns on this invention

Explanation of symbols

1 Intake pipe 2 Inlet 3 Discharge 5 and 6
7 Cutting tool 8 Cutting surface A Cutting direction P Cutting position S Suction direction a Vertical cutting section width b Inclined cutting section width h Step
t Stepped part cutting width

Claims (3)

A molded body formed by blow molding of a thermoplastic resin, wherein the discarded bag is placed on the molded body at a cutting position of the cut surface where the cut surface of the discarded bag is inclined with respect to a cross section perpendicular to the molded body. A molded body characterized by having an outward step. 2. The molded body according to claim 1, wherein the stepped portion cutting width t at the cutting position in claim 1 is not more than two-thirds of the vertical cutting section width a. The molded body according to claim 1 or 2, wherein the molded body according to claim 1 or 2 is an intake pipe.