JP2000158523A - Insert blow molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fixedly mount an insert clamping component in a narrow space with a sufficiently fixing strength by in-mold inserting an upper end of a mountain-like rib into a top part of the rib of an outer surface at a plate-like leg extended from the clamping component. SOLUTION: The insert blow molding 1 comprises a front side outer surface 2, a rear side outer surface 3, and a continued mountain-like rib 4 made of a sectional truncated shape of a stud shape as a whole on the surface 3. An insert clamping component 5 is sandwiched at an upper end of the rib 4 between two plate-like legs 10 forked and extended from the component 5 at four positions necessary to assemble with the other member of the top at predetermined positions of the rib 4, and in-mold inserted to be rigidly fixedly mounted. Thus, the component can be rigidly fixedly mounted in the narrow space of the upper end top part of the rib 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an insert blower.
More specifically, the present invention relates to a molded article having a double-walled structure having a single-layer or multilayer structure in which one or a plurality of fastening portions required for assembling with other members are provided on a part of the outer surface. The present invention relates to an insert blow molded article useful as a double-walled structural member forming a part of a product or part in the fields of exterior parts, home electric appliances, OA equipment, furniture, transportation and distribution equipment, and the like.

[0002]

2. Description of the Related Art In recent years, the use of blow molded articles has been expanded from containers such as simple bottles and tanks to structural members commonly called "double walls". And these structural members are rarely used alone like containers, and are generally attached to other larger structural members or used in combination with equivalent or smaller members. It is. For these reasons, these structural members require a “joint part” that is necessary for assembling with other members.
In many cases, fastening parts called "brackets" or the like are provided. These fastening parts are widely formed by insert-molding insert parts separately manufactured in advance.

[0003] For example, Japanese Patent Publication No. 4-36544 discloses that a "protrusion 14 is provided on an outer peripheral surface and a virtual abutting bus on the outer peripheral surface is provided for the purpose of" providing a strong tapping means in a proper position of a blow molded article ". An insert 13 having a substantially triangular conical cross section formed by (1-1) and having a hole (H) inward from the conical bottom surface is buried at the time of blow molding. Tapping pilot hole structure of blow molded articles ". Japanese Patent Application Laid-Open No. Hei 4-27521 discloses that a joint between a protruding member (an insert part) made of a polyamide resin and a parison, which is difficult to perform a strong insert molding, is strengthened. A method for obtaining an insert blow molded article having excellent integrity by applying formic acid to a surface to be processed is described.

[0004] Japanese Patent Publication No. 41646/1992 discloses an insert for preventing an error in a relative positional relationship between a plurality of fastening parts inserted due to a temporal change after molding of a molded article. A structure is described in which the form of the “mounting bracket” is a hard plate-like body in which a plurality of fastening portions are integrally provided. JP-A-3-16716 discloses that a "bracket" is integrated on a parting line by using a mold clamping operation to pinch and compress a part of the parison at the mating surfaces of the right and left split molds. And a method of inserting a "bush" previously inserted into a mold into this bracket.

[0005] The following is an example of the prior art relating to the entire insert in a broad sense, not an insert at the fastening portion. Japanese Patent Application Laid-Open No. 4-179528 discloses that "in a method of manufacturing a resin fuel tank in which a tank body is formed by blow molding, when a parison forming the tank body is clamped, resin air is injected into an air blowing hole of a mold. A method is described in which a tube is arranged, and after closing the mold, air is blown from the tube to form the tank body and simultaneously weld the tank body and the tube.

Japanese Patent Publication No. 3-76204 discloses that a parison is cut open when a parison is extruded from a die head.
A method is described in which a stay in the form of a pipe is inserted into a parison through the gap and clamped, thereby simultaneously and integrally joining the stay to a molded body. JP-A-3-16691
Japanese Patent Application Laid-Open No. 8 (1996) -1995 discloses that, in order to manufacture a plastic bumper having both ends markedly bent, a bumper main body is blown while a molded body having both ends bent in advance is inserted and held at a predetermined position of a blow molding die. A method is described in which the molded body at the both ends is welded and integrated with the molded body of the bumper-main part by molding. As described above, it is needless to say that the insert blow molding itself is publicly known, but in particular, the common insert in the conventional fastening portion is embedded in the molded product body of the part to be inserted. This is the basic shape of the part.

In fact, FIG. 1A in Japanese Patent Publication No. 4-36544 and FIG. 3 in Japanese Patent Application Laid-Open No. 4-27521, in which the shape of the insert part is directly specified in the above publication, FIG. Regarding any of FIG. 4 in Japanese Patent Publication No. 4-41646, all the embedded portions are based on the shape shown in FIG. 1 attached to the present specification. And, as described characteristically in the claims of Japanese Patent Publication No. 4-46646,
The insert part is "buried so that the entire projection including the bulging portion" is "projected from the wall surface of the hollow body to the hollow part and is wrapped in a bearing wall extending from the wall of the hollow body to the hollow part". It is. As can be seen from the above example, the conventional fastening portion is mounted on the outer surface of the molded product by selecting a place where a relatively large space can be taken with respect to the size of the insert part.

[0008] This ensures that the parison can expand around the buried portion of the insert part with sufficient margin during the blow-up, so that the buried portion is securely wrapped and firmly fixed. To do that. When the parison blows up, the portion that has reached and contacted the mold cavity surface rarely skids on the mold surface thereafter. That is, the portion in contact with the mold cavity is not further stretched. This has been experimentally confirmed by the present inventors,
Journal of the Japan Society of Plastics Processing “Molding” (Vol.6 / No.11)
/ 1994) as a paper "Visualization of blow molding".

This phenomenon is the same not only on the surface of the mold cavity but also on the surface of the insert part. In other words, the parison blow-up is a process in which a portion that has not yet reached the surface of the mold or the surface of the insert part is continuously stretched and thinned while expanding. As a result, it goes without saying that the thickness of the portion that reaches the surface of the mold cavity last becomes the thinnest. In terms of shape, when the mold cavity has a narrow and deep concave portion, this phenomenon is remarkable at the deepest portion. As described above, it is inherently not easy for the parison to smoothly expand and enter the narrow and deep concave portion of the mold cavity to form a convex portion having the same shape as the concave portion on the surface of the molded product.

Here, the basic shape of a conventional insert fastening part will be described. FIG. 1 is a cross-sectional view showing a state in which a part of a conventional insert fastening part 5 is buried and mounted in a parison 12 blown up at a place where a relatively large space can be taken. Here, the insert fastening component 5 includes a protruding fitting portion 8 that directly fits into a fastening portion of an assembly partner and a pedestal portion 9 that supports the fitting portion. A buried portion 14 having a protrusion 13 protrudes, whereby the buried portion 14 below the pedestal portion 9 is buried and fixed so as to be wrapped in the parison 12 blown up at a place where a relatively large space can be taken. In such a conventional insert fastening part 5, it is possible to bury and fix it in a place where a relatively large space can be taken, but in a place where the space is narrow, such as the top of a mountain-like rib, the parison breaks. Molding is not possible.

[0011]

According to the experiments conducted by the present inventors, if such insert molding is forcibly performed, the parison is stretched until it reaches the deepest portion of the narrower concave portion as shown in a comparative example described later. There arises a problem that the mold itself is broken during the expansion, or the corner near the tip of the buried portion of the insert part is broken in a piercing manner, making the molding itself impossible. In order to eliminate the parison breakage, the height of the buried portion, in particular, must be significantly smaller than the height of the mountain-shaped ribs. However, the mounting strength of the insert part becomes insufficient. Another problem arises in that it cannot serve as a fastening portion.

As described above, it is originally easy for the parison to smoothly expand and enter the narrow and deep concave portion of the mold cavity and form a convex portion having the same shape as the concave portion on the surface of the molded product. Absent. The present invention has been made in view of such a problem, and is relatively applicable to a narrow space such as the top of a mountain-shaped protruding portion (hereinafter referred to as a mountain-shaped rib) formed on the surface of a molded product. It is an object of the present invention to provide a blow molded product in which a large-sized insert fastening component is inserted with sufficient mounting and fixing strength.

[0013]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, a means of the present invention is not to make a portion for mounting and fixing an insert fastening part into a projecting shape buried in a molded product. That is, the upper part of the mountain-shaped rib is fixedly mounted so as to be sandwiched from both sides by two legs of the pedestal part divided into two branches.

That is, a first aspect of the present invention is a double-walled structure made of a thermoplastic resin and having a raised hollow portion (hereinafter referred to as a mountain-shaped rib) extending in a mountain shape on a part of the outer surface. Two or more plate-like legs, each of which has one or a plurality of insert fastening parts necessary for assembling with other members and extending in a bifurcated manner, at the top of the mountain-like rib. The insert-blow molding is characterized in that the upper end portion of the mountain-shaped rib is inserted and inserted so as to be firmly mounted and fixed.

According to a second aspect of the present invention, there is provided an insert fastening part comprising: a protruding fitting portion capable of directly fitting with a fastening portion of another member; a plate-shaped pedestal portion for supporting the fitting portion; The left and right end portions of the pedestal portion are bent, and the two plate-like leg portions which are extended into two forks are integrated with the anchor projection portions facing each other inside the vicinity of the tip end of each of the plate-like leg portions. The upper end of the mountain-shaped rib is sandwiched between two plate-shaped legs below the plate-shaped pedestal from both sides, and is firmly mounted and fixed so as not to be detached by the anchor projection. 2. An insert blow molded article according to claim 1, which is molded.

According to a third aspect of the present invention, the cross-sectional shape of the mountain-shaped rib of the molded product according to the present invention is formed as a substantially trapezoidal longitudinal dimension L having a bottom width Wb, an upper width Wu, and a height H. 3. An insert blow molded product according to claim 1, wherein each of the mountain-shaped ribs and the fastening part has a numerical value within the range of the following mathematical formula. . (Ridge-shaped ribs of molded product) Bottom width Wb: 20 mm ≦ Wb Top width Wu: Wu ≦ Wb Height H: Wb / 2 ≦ H ≦ 2 Wb Longitudinal L: 3 Wb ≦ L (fastening part) Fitting part Width dimension w: 5 mm ≦ w ≦ Wu / 2 Overall longitudinal dimension s: w ≦ s ≦ 2 L / 3 Leg length dimension h: 5 mm ≦ h ≦ H / 2 Leg anchor anchor-projection height dimension t: 1 mm ≦ t ≦ Wu / 1
0

According to a fourth aspect of the present invention, there is provided a molded article according to the present invention, wherein a front part and a back side are distinguishable, and a front part and a back part are provided with different functions and roles. A center line average roughness (R) defined by JIS-B0601 wherein the outer surface on the front side has an unpainted surface roughness.
a) The gloss is not more than 0.1 μm, the gloss is 60% or more as defined by JIS-K7105, and the gloss is not less than 90%, and the mountain-like rib is formed on the outer surface on the back side. An insert blow molded article according to any one of claims 1 to 3.

According to a fifth aspect of the present invention, the blow molded article comprises an outer layer formed of a thermoplastic resin having different physical properties or colors on the front outer surface and the rear outer surface, and at least one inner layer. Wherein the boundary line where the two resins forming the outer layer are in contact with each other is formed by a parting line which is a trace of a parison cutting line by a mold. Claim 1
An insert blow molded article according to any one of claims 4 to 4.

Hereinafter, the components of the present invention will be described in detail.
First, the insert blow molded article of the present invention is a single-layer or multi-layer parison melt-extruded by appropriately combining one or more of thermoplastic resins capable of being blow-molded.
It is obtained by blow molding with a blow molding die in which an insert fastening part is fixed in a predetermined cavity in advance. Any thermoplastic resin can be used here, for example, PE, PVC, PS, HIPS, AB
Preferred thermoplastic resins include general-purpose plastics such as S, AS, MMA, and PET, and engineering plastics such as polyamide (nylon), polyacetal, and polycarbonate. The resin composition, color scheme, overall shape, dimensions, weight, etc. of the blow molded product can be arbitrarily selected according to the purpose.

The raised hollow portion (hereinafter, referred to as a mountain-shaped rib) extending in the shape of a mountain formed on the outer surface of the blow-molded article of the present invention is used to reinforce the whole or a part of the molded article or to form the molded article. It is provided for the purpose of also serving as a partition. The cross-sectional shape of the mountain-shaped rib in this case is not limited and may be any shape such as a trapezoidal shape, a square shape, a triangular shape, an inverted U-shape (tunnel) shape, and a semicircular shape. Further, the rib may be continuously extended and formed on the outer peripheral portion or inside of the outer surface of the molded product, or may be independently extended and formed at a plurality of arbitrary predetermined positions. May be. In the present invention, one or a plurality of insert fastening parts are attached to the top portion at any position of the at least partially continuous raised rib.

Here, the insert fastening part of the present invention basically comprises a fastening part necessary for assembling with other members and two plate-like legs which are bifurcated and extend below the fastening part. is there. As a more preferred specific example, a protruding fitting portion capable of directly fitting with a fastening portion of another member, a plate-shaped pedestal portion supporting the fitting portion, and left and right end portions of the plate-shaped pedestal portion are bent and forked. This is an insert part in which two plate-like legs extending in a divided manner and an anchor protrusion facing each other are integrated inside the vicinity of the tip of each of the plate-like legs.

Here, the shape of the fitting portion may be any of a male type, a female type, or the like, which protrudes so as to be capable of being fitted and attached in accordance with the shape of the fastening portion of the assembling partner. The form in which the plate-shaped pedestal part is divided into two forks is optional. For example, the two pedestal parts are divided into two parts directly from the base of the fitting part in an inclined manner and further bent downward near the tip to extend. Alternatively, the base pedestal portion of the fitting portion may be formed in a flat plate shape that is not inclined, and two plate-like leg portions may be formed by bending the vicinity of the left and right end portions downward and extending. The bending angle of the two plate-shaped legs that bends the vicinity of the left and right ends of the plate-shaped pedestal portion downward is arbitrary, but at least the upper end portion of the raised rib portion can be sandwiched and compressed by the legs of the pedestal portion from both sides. Thus, it is preferable that the angle is about 90 degrees which is almost close to the inclination angle of the rib portion.

Further, the anchor projections provided on the two plate-like legs so as to face each other prevent the insert fastening parts fixed by the in-mold insert from falling off from the upper end portion of the mountain-shaped rib. Thus, a thick protrusion protruding near the tip of the leg may be formed, or a protrusion may be formed by bending the tip of the leg inward to form a protrusion, and their shapes are not limited. The material of the insert fastening part to be insert-inserted is preferably the same as the blow molded product or an injection molded product made of a different thermoplastic resin having high physical strength. Molded parts made of conductive resin, metal or other various materials may be used without any limitation. The blow-molded product of the present invention can be obtained by arranging the insert-fastened part below the pedestal portion in a mold for blow molding and performing blow molding (inmold insert).

The blow molded article of the present invention has a double wall structure and is provided with one or a plurality of insert fastening parts necessary for assembling with other members. In this case, the double-wall structure has a hollow portion inevitably obtained by blow molding from a parison, but a partially adhered portion may be formed. Specific examples of particularly preferred blow molded articles include exterior parts such as roofs, hoods, trunk lids, doors, fenders, spoilers, and bumpers of automobiles, and doors of home appliances such as refrigerators and washing machines. Doors for OA equipment such as housings, copy machines, printers, and facsimile machines, housings or partitions in homes, doors, furniture such as top and side panels of desks, and transportation of boxes, cases, containers, etc. Examples include parts used for side plates and lids of distribution equipment.

[0025]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an insert blow molded product according to an embodiment of the present invention. First, FIG. 2 is a partially cutaway perspective view of a single-door type door of a refrigerator which is an example of an insert blow-molded product of the present invention. Here, the insert blow-molded product 1 comprises a front outer surface 2 and a back outer surface 3, and a back outer surface 3.
In general, there is a continuous mountain-shaped rib 4 having a trapezoidal cross section in the shape of a "sun", and the top of the mountain-shaped rib 4 at a predetermined position is inserted at four points necessary for assembly with other members. The upper part of the mountain-like rib 4 is inserted and inserted firmly by two plate-like legs 10 which are bifurcated and extend so as to be firmly mounted and fixed. It is a thing. In FIG. 2,
In order to clearly show the mounting position of the insert fastening part 5, the rear outer surface 3 is drawn toward the front, and the hatched portion in FIG. Although only one typical mounting state of the insert fastening component 5 is illustrated, the mounting positions of the remaining three insert fastening components 5 are indicated by circles.

This insert blow-molded product 1 is a trial product with a single-door type door of a refrigerator in mind, and the back side is the surface facing the inside of the refrigerator. A mountain-shaped rib 4 in the shape of a "sun" formed on the outer surface 3 on the back side thereof is a two-tiered rack (not shown) for storing other members such as canned beads and milk packs. The insert fastening part 5 is used for assembling the fastening portion of the rack to the top of the mountain-shaped rib at a predetermined position. The front outer surface 2 is literally the outer surface of the refrigerator, and in particular, the outer surface of the door is a decorative surface as the face of the refrigerator. Therefore, the surface roughness without painting has a center line average defined by JIS-B0601. Roughness (Ra) of 0.1 μm or less and glossiness of JIS-K7
It is formed on a so-called mirror surface having a 60-degree mirror glossiness of 90% or more defined by 105. There are various colors on the front side outer surface, but the back side outer surface is white. The boundary line 6 of these two colors is located at a position slightly wrapping around the outer surface 3 on the back side.

FIG. 3 shows a ridge-shaped rib 4 and an insert fastening part 5 attached to the top of the rib 4 in a mold 7 for blow molding.
Is divided into two forks and extended by two plate-like legs 10,
It is sectional drawing which shows the state in which the upper end part of the said mountain-shaped rib was sandwiched in from both sides, and it was in-mold inserted so that it might be firmly fixed. Here, the insert fastening part 5
Is composed of a protruding fitting portion 8 which directly fits into a fastening portion of an assembling partner, a plate-like pedestal portion 9 for supporting the fitting portion, and a plate-like leg portion 10 forked, and the fitting portion 8 is formed by a mold. It is fixed to the cavity outside the cavity, while the lower part of the plate-shaped pedestal 9 is fixed so as to be located in the mold cavity.

Here, the plate-shaped pedestal portion 9 is a flat plate having a size close to the root of the fitting portion 8 so as to close the cavity outside the cavity. A parison having two plate-like legs 10 bent and extended along an angle coinciding with the plane, and anchor projections 11 projecting opposite each other inside the vicinity of the tip of each of the legs. Of these two due to the in-mold insert during blow molding by blow-up of
The top portion of the mountain-like rib 4 is sandwiched from both sides by the plate-like leg portions 10 and the anchor projections 11 and is firmly mounted and fixed.

As is apparent from FIG. 3, the insert fastening part 5 of this shape can be set in the cavity of the blow mold 7 like a conventional insert part even if it is set in the cavity of the blow mold 7.
As a result, there is no factor that hinders the expansion of the blow-up parison 12, and conversely, the depth of the recess is slightly increased (by the thickness of the pedestal portion 9) while the pedestal portion 9 and below slightly cover the mold cavity wall surface. , The blow-up of the parison 12 in the portion concerned can be easily performed, and there is no possibility that the parison 12 is broken. This is a major factor in achieving the insertion of the fastening insert part 5 having a relatively large size with a sufficient fixing strength for a narrow space such as the top of the mountain-like rib 4.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described. Embodiment 1 Specific specifications of the blow molded article 1 and the insert part 5 shown in FIG. 2 will be described in more detail. The molded product 1 shown in FIG. 2 is a two-layer blow molded product having an overall size of approximately 700 mm in length × 450 mm in width × 85 mm in maximum thickness including the height of a rib and weighing about 2.0 kg. The resin used for the front side outer layer 2 is a metallic tinted ABS resin, the back side outer layer 3 is a white ABS resin, and the inner layer is a recycled mixed resin. Further, as shown in FIG. 4, the approximate size of the mountain-like ribs 4 formed on the back side outer surface 3 is, as shown in FIG.
, Upper side width dimension Wu = 25 mm, height dimension H = 50 mm
Since the entire length L is an endless "sun" character shape, it is difficult to define where the length L is, but L≫3 Wb.

The insert part 5 is made of white ABS.
It is an injection-molded product made of a resin, and its approximate dimensions are, as shown in FIG.
= 60 mm, the height h of the leg 10 is 20 mm, and the height t of the anchor projection 11 at the tip of the leg is 2 mm.
This embodiment is based on one of the one-sided doors of the refrigerator, so the specifications are as described above. However, the numerical values such as the resin composition and the color scheme of the molded article 1, the overall dimensions and weight, etc. Is not related to the essence of the present invention. Also, the material of the insert part 5 does not need to be resin, and need not be injection molded. The insert fastening part 5 attached to the top part of the mountain-shaped rib 4 shaped like a "sun" on the back side outer surface 3 of the one-sided door of the refrigerator obtained in this embodiment has a can. It was confirmed that there was no problem in terms of strength even if the fastening portions of the upper and lower two-stage racks containing the beads, milk packs and the like were fitted.

COMPARATIVE EXAMPLE 1 FIG. 5 shows a conventional insert fastening part 5 as shown in FIG. 1 shown in FIG. FIG. 4 is a schematic cross-sectional view showing a blow-up state of the parison when the parison is performed.
The shape of the insert fastening part 5 is such that the buried portion 14 below the pedestal portion 9 buried in the molded product particularly represents the above-described conventional shape. Specifically, the pedestal 9 has a thickness of 2 m.
m, a flat plate with a width of 10 mm, and a buried portion 14 having a length of 18 mm
The fitting portion 8 has exactly the same dimensions as those of the insert fastening part of the above-described embodiment. In this case, in the case where the buried portion 14 has such a shape, there is no problem even if the pedestal portion 9 is not particularly special in terms of function as a fastening portion.
However, in order to close a gap formed when this part is set in the corresponding cavity of the mold, the width w of the fitting portion is 8 mm.
A wider base 9 is required. In Comparative Example 1, the parison 12 blown up as shown in FIG.
No. 4 occurred and molding was impossible.

Comparative Example 2 A schematic diagram of a cross-section of a parison in a blow-up state during insert molding in a blow molding die cavity using an insert fastening part 5 as shown in FIG. Is shown.
This insert fastening part 5 is provided with three small truncated cone-shaped protrusions having a height of 5 mm in a longitudinal dimension s = 60 mm to form an embedding portion 14, and instead, the pedestal portion 9 has a flat plate shape having a thickness of 6 mm. It is. In FIG. 6, since the cross section is perpendicular to the longitudinal direction, only one truncated conical projection is visible. By reducing the size of the buried portion 14 in this way, the parison 12
The result was that the parison was not completely blown up into a narrow space on the thick side surface of the pedestal portion 9 and the tear 14 was generated, resulting in molding failure. It was possible.

Comparative Example 3 A schematic diagram of a cross section of a parison in a blow-up state at the time of insert molding in a blow molding die cavity using an insert fastening part 5 as shown in FIG. Is shown.
The insert fastening part 5 has a thickness of 6 mm so that the protruding embedded part is removed and the pedestal part 9 itself has the function of the embedded part.
The side of the pedestal 9 is cut into a triangular shape. Also in this case, the parison 12 did not completely blow up on the side surface of the pedestal portion, but was torn in the middle, and molding was impossible.

Comparative Example 4 A cross-sectional schematic view of the parison in a blow-up state at the time of insert molding in the blow molding die cavity using the insert fastening part 5 as shown in FIG. Is shown.
In this insert fastening part 5, the buried portion 14 is made smaller than in Comparative Example 2, and the pedestal portion 9 is also returned to the same thickness as in Comparative Example 1. Specifically, height 3mm
Are provided with three truncated conical protrusions, and the pedestal portion 9 is formed.
Has a thickness of 2 mm. In this case, the blow-up was completely performed without breaking the parison 12 as shown in the figure. Therefore, although this insert molding seems to be a success at first glance, since the embedded portion 14 is too small, the required fixing strength as a fastening portion does not reach a required value, and the embodiment of the present invention is eventually completed. It has been found that such a large-sized structural member cannot be actually used as a fastening insert part. That is, in the comparative example 4, even if the embedded portion 14 is a typical type of the conventional type as shown in FIG.
This only shows that if the size of No. 4 is made smaller and smaller, it is possible to find a point where the molding can be performed without the occurrence of parison breakage 14 in some places.

[0036]

The insert blow-molded article of the present invention is
With the above-described configuration, in a narrow space such as a top portion of a raised portion such as a mountain-shaped rib, an insert fastening part as a fastening portion is attached to the mountain-shaped rib by a leg of a pedestal portion. The upper end portion can be firmly attached and fixed so that the upper end portion is pinched from both sides so as not to be detached by the anchor protrusion. This provides a greater degree of freedom in the product design as a structural member than in the case where a wide space must be selected and mounted as in the past, and is the basis for significantly increasing the value as a product. It is.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a basic shape of a conventional insert fastening part.

FIG. 2 is a partially cutaway perspective view showing an example of a blow molded article of the present invention.

FIG. 3 is a partial cross-sectional view showing a state where an insert fastening part is insert-inserted into a mountain-shaped rib top portion of the blow molded article of the present invention.

FIG. 4 is a sectional view showing dimensions of the insert fastening part of FIG. 3;

FIG. 5 is a partial sectional view showing a blow-up state of a parison during insert blow molding in Comparative Example 1.

FIG. 6 is a partial sectional view showing a blow-up state of a parison during insert blow molding in Comparative Example 2.
It is sectional drawing.

FIG. 7 is a partial sectional view showing a blow-up state of a parison during insert blow molding in Comparative Example 3.

FIG. 8 is a partial cross-sectional view showing a blow-up state of a parison during insert blow molding in Comparative Example 4.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 blow-molded product 2 front-side outer surface 3 back-side outer surface 4 mountain-shaped rib 5 fastening insert part 6 two-color boundary line 7 blow-molding die 8 fitting part 9 pedestal part supporting fitting part DESCRIPTION OF SYMBOLS 10 Leg part 11 Anchor projection 12 Blow-up parison 13 Swelling part 14 Buried part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29L 31:34 31:44 (72) Inventor Tetsu Furuki 15-1 Shinko, Kisarazu-shi, Chiba Nippon Steel Chemical Co., Ltd. Inside the Shikisha Product Development Center (72) Inventor Masao Takaso 15-1 Shinko, Kisarazu-shi, Chiba Nippon Steel Chemical Co., Ltd. Inside the Shikisha Product Development Center (72) Inventor Koji Ono 4-chome Takaidamoto-dori, Higashi-Osaka-shi, Osaka No. 5 Inside Matsushita Refrigeration Co., Ltd. (72) Inventor Kiyoshi Nishida 4-5-2-5 Takaida Hondori, Higashi-Osaka City, Osaka Prefecture Inside Matsushita Refrigeration Machine Co., Ltd. (72) Inventor Kazuhiro Morii Kiyoshi Takaida, Higashi-Osaka City, Osaka Prefecture 4-2-5 Matsushita Refrigeration Co., Ltd. (72) Inventor Hiroshi Tsujita 4-2-5 Takaida Hondori, Higashiosaka-shi, Osaka Matsushita Refrigeration Co., Ltd. F-term (reference) 3D023 AA01 AB01 AC02 AC08 AC11 AC15 AC25 AD04 AD17 AD22 AD26 4F208 AD24 AG06 AG28 AR12 AR20 LA01 LB12 LB22 LB28 LD14 LG06 LJ05 LN01

Claims (6)

[Claims] 1. A blow molded product having a double-walled structure made of a thermoplastic resin and having a raised hollow portion (hereinafter referred to as a mountain-shaped rib) extending in a mountain shape on a part of an outer surface thereof. One or a plurality of insert fastening parts necessary for assembling with other members are mounted on the top of the mountain-like rib by two plate-like legs extending in a forked manner, thereby forming an upper end portion of the mountain-like rib. An insert-blow molded product characterized in that it is insert-inserted so that it is firmly mounted and fixed by sandwiching it from both sides. 2. An insert fastening part comprising: a protruding fitting portion directly fittable with a fastening portion of another member; a plate-shaped pedestal portion supporting the fitting portion; and left and right end portions of the plate-shaped pedestal portion. Are bent and bifurcated into two plate-like legs, and the plate-like legs are integrated with the anchor projections facing each other inside the vicinity of the tip of each of the plate-like legs. The upper end portion is sandwiched by two plate-like legs below the plate-like pedestal from both sides, and is firmly mounted and fixed so as not to be detached by the anchor protrusion. Insert blow according to item 1
Molding. 3. The cross section of the mountain-shaped rib has a base width W
b, a blow-molded article formed as a substantially trapezoidal longitudinal dimension L having an upper side width dimension Wu and a height dimension H, wherein each dimension of the mountain-shaped rib and the fastening part is a numerical value within the range of the following numerical formula. 3. An insert-blow molded product according to claim 1, wherein the molded product is an insert blow molded product. (Ridge-shaped ribs of molded product) Bottom width Wb: 20 mm ≦ Wb Top width Wu: Wu ≦ Wb Height H: Wb / 2 ≦ H ≦ 2 Wb Longitudinal L: 3 Wb ≦ L (fastening part) Fitting part Width dimension w: 5 mm ≦ w ≦ Wu / 2 Overall longitudinal dimension s: w ≦ s ≦ 2 L / 3 Leg length dimension h: 5 mm ≦ h ≦ H / 2 Leg anchor anchor-projection height dimension t: 1 mm ≦ t ≦ Wu / 1
0 4. The blow-molded article is a structural member with a fastening component having a front side and a back side which can be distinguished from each other, and having different functions and roles provided to a front side outer surface and a back side outer surface. The surface roughness when the outer surface is unpainted has a center line average roughness (Ra) of 0.1 μm or less defined by JIS-B0601,
The glossiness is 60 degree mirror glossiness defined by JIS-K7105 of 90% or more, and the mountain-like ribs are formed on the outer surface on the back side. 2. An insert blow molded article according to claim 1. 5. The multilayer blow-molding wherein the blow-molded article comprises an outer layer formed of a thermoplastic resin having different physical properties or colors on the front outer surface and the rear outer surface, and at least one inner layer. 2. A product according to claim 1, wherein a boundary line at which the two resins forming the outer layer are in contact with each other is formed by a parting line which is a trace of a parison cutting line formed by a mold. 5. An insert-blow molded product according to any one of 4. 6. The blow-molded article according to claim 6, wherein the blow-molded article is an automobile roof,
Exterior parts such as bonnets, trunk lids, doors, fenders, spoilers, bumpers, etc. or doors and housings for household appliances such as refrigerators and washing machines, and doors and housings for OA equipment such as copy machines, printers and facsimile machines. Parts or doors, doors, furniture such as table tops and side plates of desks, or parts used for side plates and lids of transport and distribution equipment such as boxes, cases and containers. An insert blow molded product according to any one of claims 1 to 4.