JPH09239818A - Blow molded product and blow mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a burr mark inconspicuous while facilitating the treatment processing thereof. SOLUTION: In a pair of blow molds having cut-off blades 21 provided to the peripheral part of a cavity C, edge parts 22 coming into contact with each other by mold clamping are formed to both cut-off blades 21, 21 and, further, the expansion parts 23 protruding only the edge parts 22 of one cut-off blades 21 toward the cavity are formed so as to provide a stepped part 8 to the parting line part 24 on the cavity side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow-molded article such as a headrest skin and a blow-molding die for producing the blow-molded article.

[0002]

Blow-molded articles (FIG. 8) such as a headrest skin 91 made of vinyl chloride resin or the like conventionally use blow-molding dies 92, 93 having a die structure as shown in FIGS. 9 and 10. Was common. There, the part 96 is made to have the same smooth surface so that the parting line P does not adversely affect the appearance of the product. Also,
Usually, the blade thicknesses of both of the opposing cutting blades 94 and 95 are the same so that they are superposed exactly by closing the mold.

[0003]

However, in the conventional blow molding die, as described above, the parting line portions 96 to be joined by closing the die must be machined so as to have the same smooth surface. Was difficult. Further, a pair of mating molds 92 with the parting line P interposed therebetween,
Since 93 is finished on the same surface, scratches, irregularities, etc. were likely to occur during the processing. On the other hand, when the blow-molded products produced from the blow-molding dies 92 and 93 are to be completed as products, usually, burrs appearing on the parting line are cut with a cutter or the like, but the process is difficult. Since the parting line part has a smooth flat surface, the quality was not stable due to cutting too deep or conversely leaving burrs. Then, it was easy for the cutter to rub the design surface at the time of cutting and scratch the design surface.

In addition, considering the case where the blow-molded product is used for a headrest with a wrinkle for a headrest, the burr mark 97 cut by a cutter has no wrinkle and is glossy.
It often caused quality problems. When the headrest using the outer skin is attached to the front seat back of a passenger car or the like, the burr mark 97 becomes a glossy surface different from other design surfaces due to the adjustment of light rays and catches the eyes of the passenger in the rear seat, It was reflected in a defective product. The passengers in the back seat often look forward, and it is easy to notice such a defect.

The present invention solves the above problems, and an object of the present invention is to provide a blow-molded article and a blow-molding die in which burr marks are inconspicuous and whose processing is easy.

[0006]

In order to achieve the above object,
The gist of the present invention as set forth in claim 1 is a blow-molded article characterized in that a step is formed in a parting line portion relating to blow molding, and burrs appearing on a higher step side of the step are removed. Further, the gist of the present invention according to claim 2 is to provide a pair of blow molding dies having an edging blade in a peripheral portion of a cavity, wherein the edging portion is formed on both edging blades,
A blow molding die is characterized in that only one blade portion of one food cutting blade is formed with a bulging portion protruding toward the cavity side so that a step is provided at the cavity side parting line portion. The blow mold of the present invention according to claim 3 has a step of 1.0 mm to 2.0 due to the bulging portion of claim 2.
It is characterized by being in the range of mm.

When the parting line portion is provided with a step as in the invention described in claims 1 and 2, burrs formed there can be cut with the cutter or the like inclined, so that the surrounding design surface is scratched. You can easily remove the burr without The oblique cut can prevent the blow-molded product from touching anything other than the burr, so that there is no possibility of rubbing the surrounding design surface. Of course, as a result of the oblique cutting being adopted, the deburring work can be performed easily, and as a result, the conventional defect that the surroundings of the burr or the burr is left uncut can be improved. Further, when the step due to the bulging portion is set in the range of 1.0 mm to 2.0 mm as in the invention described in claim 3, there is no problem in view of the design of the blow molded product. In addition, the blow-molded product is applied to the headrest skin of passenger cars, etc., and in the front seat headrest where the higher step of the step is arranged on the rear side, it is possible to hide the burr mark well behind the step, Even if the burr mark becomes a glossy surface, it will be hard to catch the eyes of the passenger in the back seat.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a blow-molded article and a blow-molding die (hereinafter referred to as "blow-molding") according to the present invention will be described in detail below. 1 to 7 show one embodiment of a blow-molded product and a blow-molding die according to the present invention. FIG. 1 is a cross-sectional view of the blow mold in a mold-closed state, and FIG. 2 is an enlarged view of part A of FIG.
3 is a cross-sectional view of the blow-molded product molded by the blow mold of FIG. 1, FIG. 4 is a partial cross-sectional perspective view showing a state in which the burrs of the blow-molded product of FIG. 3 are removed, and FIG. 5 is a burr trace of FIG. FIG. 6 is an enlarged cross-sectional view of the surroundings, and FIG. 6 is a completed perspective view of the blow-molded product of FIG. As a blow-molded product, the headrest skin attached to the upper end of the seat back of a passenger car will be taken up. In addition, each drawing is drawn by emphasizing the characteristic part.

(1) Blow Mold The blow mold 2 of the headrest skin 1 has a cross-sectional shape as shown in FIG. FIG. 1 shows a mold closed state, in which a pair of mating molds 2a and 2b (blow mold 2) is used to form the skin 1.
C cavity C is formed. The blow mold 2 is provided with a food cutting blade 21 around the cavity C.
The blade portions 22 of are engaged with each other when the mold is closed. The food cutting blade 21 has a role of cutting off the parison and sealing it at the same time when the mold is closed so as to prevent air from leaking out. Regarding one of the cutting blades 21 (on the left side in FIG. 1), the blade portion 22 protrudes toward the cavity side, and a bulge portion 23 is formed. Due to the bulging portion 23, a step δ is formed on the parting line portion 24 on the cavity side.

The blade thickness t of the blade portion 22 is appropriately selected according to blow molding resin or the like. For example, in the present embodiment, the blade thickness t is about 0.3 mm (FIG. 2). The bulging part 2
The step difference δ associated with 3 is 1.0 mm to 2.0 mm, and more preferably 1.0 mm to 1.5 mm. This range is preferable because when the step δ is less than 1.0 mm, the action and effect of the present invention having the step cannot be expected so much, while the step δ is 2.0 mm (more strictly 1.5 mm). This is because, when the value exceeds, the imbalance in appearance starts to stand out from a design standpoint.

The vertical cross-sectional shape of the blow mold 2 is basically the same as that shown in FIG. 9, a die 3 of a known extruder is provided above the blow mold 2, and a blow air inlet is provided below the blow mold 2. 4 are provided (see FIG. 9). The blow-in port 4 may be on the die 3 side. The other components of the blow mold 2 are basically the same as the general blow mold, and the description thereof is omitted here.

Using the blow mold 2, the headrest skin 1 is manufactured as follows. First, under the mold open state,
A thermoplastic resin (here, a soft vinyl chloride resin) is plasticized, and an annular parison (not shown) is extruded. After the parison reaches the lower end of the blow mold 2, the mold is closed. At this stage, the food cutting blades 21 and 21 cut off the parison protruding from the blow mold 2 and simultaneously seal the parison. Next, before the parison is cooled and solidified, air is blown into the inside from the blow-in port 4 to expand the parison and press it against the cavity surface. Then, the parison is cooled and solidified to obtain the headrest skin 1 having a step in the parting line portion 13 as shown in FIG. 3 (left side).

(2) Blow-Molded Product The headrest skin 1 (blow-molded product) obtained by blow molding using the above-mentioned blow mold 2 has a bulge 23 so that a step is formed at the parting line portion 13. δ is formed. However, in the headrest skin 1 taken out after the blow molding, the burr 11 as shown in FIG. 3 remains where the blade portions 22 and 22 are engaged, that is, at the tip of the high step H of the step δ. ing. The parison remains between the blade portions 22 in the blow molding process. Therefore, in the post-processing, the burr 11 is cleanly removed by using the cutter 5 or the like, and a desired product is finished. Conventionally, since there was no step δ and the vicinity of the burr was flat, the design surface 1a was often dug up. However, the removal work of the burr 11 in the present embodiment is
Since there is the step δ, there is little risk that the important skin portion (design surface 1a) is cut off. It should be noted that not only the headrest skin 1 but also the design surface 1a of a blow-molded product usually has a matte grain pattern such as leather and texture.

The cutter 5 can be used by cutting the burr 11 horizontally as shown in FIG.
Burr 11 by using the cutter 5 at an angle as shown in (b).
It is more preferable to cut off. According to the burr removal method of (a), the burr mark 1
Since the glossy surface of No. 2 is flush with the design surface 1a on the high step side H, the design surface 1a is easily damaged. On the other hand, according to the burr removal method (b), there is no place where the cutter 5 hits other than the root part of the burr 11 to be cut off, and there is no fear of rubbing the design surface 1a in the vicinity. Further, the cutter 5 is also easy to handle and the workability is improved.

Further, the headrest skin 1 attached to the front seat back S is more convenient when the headrest G having the lower step L of the step δ on the front side and the higher step H on the rear side is finished. (Fig. 6). Incidentally, reference numeral 7 in FIG.
Indicates a foam, and reference numeral 8 indicates a stay. By the way, FIG.
According to the horizontal cut of (a), when the occupant sitting on the rear seat diagonally rearward looks at the front (the direction of the arrow in FIG. 5 (a)), the gloss surface of the burr mark 12 is improved, although it is improved compared to the conventional one. May catch your eyes. On the other hand, according to the diagonal cut of FIG. 4B, even if the occupant M sitting on the rear seat looks forward (in the direction of the arrow in FIGS. 5B and 6), the burr marks 12
(Glossy surface) enters the blind spot and is hidden, which has the advantage of not being visible at all. On the other hand, in the case where the headrest skin 1 (headrest) is attached to the rear seat back, the occupant M when the high tier H is on the front side and the low tier L is on the rear side.
From this, the burr mark 12 is hidden and convenient. However, the method of arranging the headrest skin 1 is not limited to this.

(3) Effect According to the blow mold and the blow-molded product of the above-described embodiment, when the burr 11 formed on the parting line portion 13 is removed, the step δ is provided. It becomes possible, and there is no longer a worry of rubbing or scratching the design surface 1a near the burr. Further, conventionally, since the burr 11 is projected from the flat surface, the cutter blade itself or the back of the hand hits the design surface 1a, which makes the deburring work difficult, but the step δ makes it easier. That is, since the cutter or the like can be floated from the design surface 1a, the burr 11 can be easily processed. Bali mark 12
Even smaller, less noticeable. Then, such a step δ
If the thickness is in the range of 1.0 mm to 2.0 mm, the finished product does not have a design sense and the cutter 5 is easy to handle, so the parting line portion 13 is too deeply shaved or conversely burred. It is possible to solve the conventional inconvenience in which 11 is left behind.

Further, considering the case where the blow molded product is used for the front side headrest skin 1, the lower side L of the step δ is set to the front side and the burr 11 is formed by oblique cutting.
If the burr mark 12 is removed, the burr mark 12 will enter the blind spot from the rear seat (Fig. 5 (b)), so the occupant M on the rear seat will not be able to see the burr mark 1
2 is hard to notice (Fig. 6). In addition, since the blind spot is formed on the lower step L (front side) related to the step δ, the worker does not have to be nervous about the scratch on this portion, and as a result, the deburring work is performed. As a result, the work man-hours can be shortened.

In the present invention, the present invention is not limited to those shown in the above embodiments, but can be variously changed within the scope of the present invention depending on the purpose and application. The blow-molded article of the headrest skin 1 according to the embodiment may be a perforated headrest skin 1 as shown in FIG. 7, for example. Of course, blow molded products are
Not limited to the headrest skin, it can be applied to various blow molded products. Further, in the present embodiment, the burr 11 is removed by using the cutter 5, but the present invention is not limited to this method. For example, the burr 11 is softened and then the burr 11 is removed.
It is also possible to employ a method of pressing (pressing) a pressing body to eliminate (remove) the burr 11.

[0019]

As described above, the blow-molded article and the blow-molding die of the present invention make the burr marks inconspicuous and the processing can be facilitated. Therefore, the effect of improving the product quality and productivity is excellent. Exert.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a blow molding die in a mold closed state, which is one embodiment of the blow molding die of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

3 is a cross-sectional view of a blow-molded article of the present invention molded by the blow-molding die of FIG.

FIG. 4 is a partial cross-sectional perspective view showing a state where burrs are removed from the blow-molded product of FIG.

5 is an enlarged cross-sectional view around a burr mark in FIG.

6 is a completed perspective view of the blow-molded product of FIG. 5 commercialized.

FIG. 7 is a partial cross-sectional perspective view commercialized using another blow-molded product (headrest skin).

FIG. 8 is a perspective view of a finished product commercialized using a conventional blow-molded product (headrest skin).

9 is a schematic vertical cross-sectional view of a blow mold for producing the blow-molded product of FIG.

10 is a sectional view taken along line IV-IV of FIG.

[Explanation of symbols]

 1 Headrest skin (blow-molded product) 11 Burr 13 Parting line part 2 Blow molding die 21 Corrosion cutting blade 22 Blade part 23 Bulging part C Cavity H Higher step (higher step side) L Lower step ( Lower step) δ Step

Claims (3)

[Claims] 1. A blow-molded article, characterized in that a step is formed in a parting line portion relating to blow molding, and burrs appearing on the higher step side of the step are removed. 2. A pair of blow molding dies having an edging blade on the periphery of a cavity, wherein the edging is formed on both edging blades, and only one of the edging blades protrudes toward the cavity side. The blow molding die is characterized in that a step is formed so that a step is formed in a parting line portion on the cavity side. 3. The step due to the bulging portion is 1.0 mm to
The blow mold according to claim 2, which is in a range of 2.0 mm.