JPH0834052A - Method and mold for producing bamper beam - Google Patents
Method and mold for producing bamper beamInfo
- Publication number
- JPH0834052A JPH0834052A JP17238094A JP17238094A JPH0834052A JP H0834052 A JPH0834052 A JP H0834052A JP 17238094 A JP17238094 A JP 17238094A JP 17238094 A JP17238094 A JP 17238094A JP H0834052 A JPH0834052 A JP H0834052A
- Authority
- JP
- Japan
- Prior art keywords
- surface portion
- front surface
- bumper beam
- mold
- parison
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
- B29C49/42—Component parts, details or accessories; Auxiliary operations
- B29C49/48—Moulds
- B29C49/4802—Moulds with means for locally compressing part(s) of the parison in the main blowing cavity
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
- B29C49/42—Component parts, details or accessories; Auxiliary operations
- B29C49/48—Moulds
- B29C49/4802—Moulds with means for locally compressing part(s) of the parison in the main blowing cavity
- B29C2049/4805—Moulds with means for locally compressing part(s) of the parison in the main blowing cavity by closing the mould halves
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
- B29C49/02—Combined blow-moulding and manufacture of the preform or the parison
- B29C49/04—Extrusion blow-moulding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2031/00—Other particular articles
- B29L2031/30—Vehicles, e.g. ships or aircraft, or body parts thereof
- B29L2031/3044—Bumpers
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
- Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、ブロー成形されるバン
パービームの製造方法およびその金型に関し、特に自動
車のバンパービーム等に利用できる。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a blow-molded bumper beam and a mold for the same, and is particularly applicable to automobile bumper beams and the like.
【0002】[0002]
【背景技術】従来、自動車用のバンパーにおいては、そ
の裏側に長手方向に連続した金属製のバンパービームを
設けて補強し、衝突時の変形を小さくすることがなされ
ている。また、近年、軽量化、形状の自由度、復元性、
耐食性、耐塑性変形性等の要求から、ブロー成形により
一体成形された合成樹脂製のバンパービームが用いられ
るようになっている。そして、ブロー成形等による合成
樹脂成形では、バンパービームの表面の形状成形性がよ
いため、バンパービーム自体をバンパーとして用いるこ
ともある。2. Description of the Related Art Conventionally, in a bumper for an automobile, a metal bumper beam that is continuous in the longitudinal direction is provided on the back side of the bumper to reinforce the bumper beam to reduce deformation during a collision. In recent years, weight reduction, freedom of shape, restoration,
Due to requirements for corrosion resistance, plastic deformation resistance, and the like, a synthetic resin bumper beam integrally formed by blow molding has been used. In synthetic resin molding such as blow molding, the shape of the surface of the bumper beam is good, so the bumper beam itself may be used as a bumper.
【0003】さらに、このような樹脂製のバンパービー
ムないしはバンパーにおいては、前記の要求と強度の向
上とが図られる構造が求められており、肉厚を厚くする
などの重量を増加させることなく、バンパービームとし
ての強度を向上させることができるリブ構造を長手方向
に有し、かつブロー成形によって容易に一体成形するこ
とができるバンパービームが提案されている。Further, in such a bumper beam or bumper made of resin, a structure that meets the above-mentioned requirements and an improvement in strength is required, and without increasing the weight such as increasing the wall thickness, A bumper beam has been proposed which has a rib structure capable of improving the strength as a bumper beam in the longitudinal direction and which can be easily integrally molded by blow molding.
【0004】樹脂製のバンパービームの材質としては一
般的に熱可塑性樹脂が用いられる。熱可塑性樹脂の例と
しては、ポリプロピレン、ポリカーボネート、ポリアミ
ド、ポリエチレンテレフタレート、ポリスチレン、ポリ
オキシメチレン、ABS樹脂、AS樹脂、ポリフェニレ
ンオキシド、ポリフェニレンスルフィドなどがある。さ
らに、これらにエチレン−プロピレンゴム、エチレン−
プロピレン−ジエン三元系ゴム等のゴム類および/また
はガラス繊維、炭素繊維、タルク、マイカ、炭酸カルシ
ウムなどの充填剤を配合したものを挙げることができ
る。A thermoplastic resin is generally used as the material of the resin bumper beam. Examples of the thermoplastic resin include polypropylene, polycarbonate, polyamide, polyethylene terephthalate, polystyrene, polyoxymethylene, ABS resin, AS resin, polyphenylene oxide, and polyphenylene sulfide. Furthermore, ethylene-propylene rubber, ethylene-
Examples thereof include rubbers such as propylene-diene ternary rubber and / or glass fibers, carbon fibers, talc, mica, calcium carbonate and the like.
【0005】図10と図11とには、このようなバンパ
ービームの従来の一実施例であるバンパービーム70の
外観図と、長手方向の略中央であってこの長手方向に直
交する断面の構造とが示されている。図10において、
バンパービーム70は、成形品の主な外観形状を形成す
る本体71を備えている。この本体71は長手方向中間
部分が表面側(バンパービームを車体に配置した際に、
その車体取付側の面に対向する面側)に突出するように
湾曲しているとともに、その両端部には裏面側(バンパ
ービームを車体に配置した際に、その車体取付側の面
側)が平面とされた取付面72を備えている。また、そ
れぞれの取付面72にはこの表面より垂直に突出するよ
うに3本のボルト73がインサート成形されている。FIG. 10 and FIG. 11 are external views of a bumper beam 70, which is a conventional example of such a bumper beam, and a structure of a cross section that is substantially in the center in the longitudinal direction and is orthogonal to the longitudinal direction. And are shown. In FIG.
The bumper beam 70 includes a main body 71 that forms the main appearance shape of the molded product. The main body 71 has a longitudinal intermediate portion on the front surface side (when the bumper beam is arranged on the vehicle body,
It is curved so as to project to the surface opposite to the surface on which the vehicle body is mounted), and the back surface (the surface side on the vehicle body mounting side when the bumper beam is placed on the vehicle body) is on both ends. It is provided with a flat mounting surface 72. Further, three bolts 73 are insert-molded on each mounting surface 72 so as to project perpendicularly from this surface.
【0006】図11において、バンパービーム70はそ
の表面側に表面部74を有し、この表面部74よりも裏
面側に裏面部75を備えている。表面部74は両端が裏
面部75の両端に向かって延びてこれらの両端にそれぞ
れ接続され、ここでは断面が略C字形となっている。裏
面部75は、断面形状が両側略平面で中間部分が表面側
に突出した形状であり、この突出した部分は長手方向に
連続しかつ先端が表面部74裏面に密着接続された接合
部76となっている。さらに、本体71の内部には接合
部76によって仕切られた二つの中空部78が形成され
ている。In FIG. 11, the bumper beam 70 has a front surface portion 74 on the front surface side and a back surface portion 75 on the back surface side of the front surface portion 74. Both ends of the front surface portion 74 extend toward both ends of the back surface portion 75 and are connected to these both ends, respectively, and the cross section thereof has a substantially C-shape. The back surface portion 75 has a cross-sectional shape that is substantially flat on both sides and has an intermediate portion that protrudes toward the front surface side. Has become. Further, inside the main body 71, two hollow portions 78 partitioned by the joint portion 76 are formed.
【0007】図12には、バンパービーム70の製造に
使用するブロー成形用の金型80の断面が示されてい
る。この断面はバンパービーム70の長手方向の略中央
に対応する位置の長手方向直交断面である。図12にお
いて、金型80はバンパービーム70の主に表面部74
を形成する表面部形成用型80Aと主に裏面部75を形
成する裏面部形成用型80Bとを備え、図中左右方向の
略中央からこれらの表面部形成用型80Aと裏面部形成
用型80Bとに分割する分割面82を備えている。ま
た、金型80は断面が略C字形のキャビティ81を有
し、このキャビティ81は内面にバンパービーム70の
表面部74を形成する表面部形成面83と裏面部75を
形成する裏面部形成面84とを備え、裏面部形成面84
はその略中間が表面部形成面83の近傍に向かって突出
している裏面部突出部面84Aを備えている。FIG. 12 shows a cross section of a blow molding die 80 used for manufacturing the bumper beam 70. This cross section is a cross section orthogonal to the longitudinal direction at a position corresponding to substantially the center of the bumper beam 70 in the longitudinal direction. In FIG. 12, the mold 80 is mainly a surface portion 74 of the bumper beam 70.
And a back surface forming mold 80B mainly forming the back surface 75, and the front surface forming mold 80A and the back surface forming mold 80A It has a dividing surface 82 for dividing into 80B. The die 80 has a cavity 81 having a substantially C-shaped cross section, and the cavity 81 has a front surface forming surface 83 forming a front surface 74 of the bumper beam 70 and a back surface forming surface forming a back surface 75 on its inner surface. And a back surface forming surface 84
Has a rear surface protruding portion surface 84A whose substantially middle portion protrudes toward the vicinity of the front surface forming surface 83.
【0008】図12には、ブロー成形によるバンパービ
ーム70の製造方法の一例が示されている。先ず、加熱
溶融した成形樹脂を高位置に設けられた押出機90から
縦方向に筒状のパリソン70Aとして押し出す。この
際、パリソン70Aを分割されたブロー成形用の金型8
0の表面部形成用型80Aと裏面部形成用型80Bとの
間に位置させ、インサート成形されるボルト73を予め
裏面部形成用型80Bの内部に位置させておく(図12
(A)参照)。FIG. 12 shows an example of a method of manufacturing the bumper beam 70 by blow molding. First, the heat-melted molded resin is extruded in the vertical direction as a cylindrical parison 70A from the extruder 90 provided at a high position. At this time, the parison 70A is divided into blow molding dies 8
0 between the front surface forming die 80A and the back surface forming die 80B, and the insert-molded bolt 73 is previously placed inside the back surface forming die 80B (FIG. 12).
(See (A)).
【0009】次に、パリソン70Aが十分長くなったと
き、このパリソン70Aの一部を長手方向に沿って金型
80に設けられた分割面82で挟み込むと同時に、パリ
ソン70Aの長手方向の両端を挟み切る。さらに、表面
部形成用型80Aの外面であって長手方向の上方に設け
られた吹き込み口85からパリソン70Aの内部に空気
を吹き込み、パリソン70Aを膨張させてせてキャビテ
ィ81の内面に密着させる(図12(B)参照)。この
後、冷却するのを待って金型80を開いてバンパービー
ム70を取り出す(図12(C)参照)。Next, when the parison 70A becomes sufficiently long, a part of the parison 70A is sandwiched by the dividing surfaces 82 provided in the mold 80 along the longitudinal direction and, at the same time, both ends of the parison 70A in the longitudinal direction are sandwiched. Clip it. Furthermore, air is blown into the inside of the parison 70A from the blowing port 85 provided on the outer side of the surface portion forming die 80A in the upper part of the longitudinal direction, and the parison 70A is expanded and brought into close contact with the inner surface of the cavity 81 ( See FIG. 12B). After that, after cooling, the mold 80 is opened and the bumper beam 70 is taken out (see FIG. 12C).
【0010】ここで、図12に戻って、図12は金型8
0の断面を示しているとともに、図12(B)の状態を示
しており、パリソン70Aの挟み込みが完了する直前の
状態(図12(A)参照)と直後の状態(図12(B)参
照)とを示している。図12(A)において、金型80の
挟み込みが進むにつれて、パリソン70Aのうち裏面部
形成用型80Bと対向する面の一部であって長手方向に
連続した面は、裏面部突出部面84Aによって挟み込み
方向に押し込まれる。Now, returning to FIG. 12, FIG.
12 shows the state of FIG. 12B as well as the cross section of 0, and the state immediately before the sandwiching of the parison 70A is completed (see FIG. 12A) and the state immediately after that (see FIG. 12B). ) Is shown. In FIG. 12 (A), as the sandwiching of the mold 80 progresses, a part of the surface of the parison 70A facing the back surface forming mold 80B, which is continuous in the longitudinal direction, is a back surface projecting surface 84A. It is pushed in by the pinching direction.
【0011】さらに、図12(B)において、挟み込みが
完了すると同時に裏面部突出部面84Aによって押し込
まれた部分は、表面部形成用型80Aと対向する面の内
面と密着して接合部76を形成する。また、この挟み込
みが完了する際に、パリソン70Aの一部は長手方向に
沿って表面部形成用型80Aと裏面部形成用型80Bと
の分割面82の間に挟み込まれる。Further, in FIG. 12B, at the same time when the sandwiching is completed, the portion pressed by the back surface projecting portion surface 84A comes into close contact with the inner surface of the surface facing the front surface forming die 80A to form the bonding portion 76. Form. When the sandwiching is completed, a part of the parison 70A is sandwiched along the longitudinal direction between the dividing surfaces 82 of the front surface forming die 80A and the back surface forming die 80B.
【0012】次に、パリソン70Aの内部の中空部78
に空気が吹き込まれると、パリソン70Aはその肉厚を
減じながら矢印の方向に膨張してキャビティ81の内面
に密着し、これにより前述した図10、11のバンパー
ビーム70が形成される。この際、バンパービーム70
には、図11において表面部74の両端から裏面部75
に向かって延びたそれぞれの略中央に分割面の跡77が
形成される。ここで、表面部74のうち分割面の跡77
よりも表面側に位置した部分は表面前方部74Aとなっ
ており、裏面側に位置した部分は表面後方部74Bとな
っている。Next, the hollow portion 78 inside the parison 70A.
When air is blown into the parison 70A, the parison 70A expands in the direction of the arrow while reducing its wall thickness and comes into close contact with the inner surface of the cavity 81, thereby forming the bumper beam 70 shown in FIGS. At this time, the bumper beam 70
In FIG.
Traces 77 of the dividing surface are formed at the substantially center of each extending toward. Here, traces 77 of the division surface of the surface portion 74
The portion located on the front surface side is a front surface portion 74A, and the portion located on the back surface side is a surface rear portion 74B.
【0013】[0013]
【発明が解決しようとする課題】しかしながら、図10
から図13に示したような従来例では、パリソン70A
のうち分割面82を境として、表面部形成用型80Aに
向かって膨張する部分と裏面部形成用型80Bに向かっ
て膨張する部分とでは、その膨張量が異なるため肉厚の
変移量に差異が生じる。つまり、裏面部75のうち接続
部76を除いた部分と表面後方部74Bとにおいては、
膨張以前のパリソン70Aでの肉厚T0(図13参照)
と膨張後のバンパービーム70での肉厚T1(図11参
照)との比であるブローアップ比(T0/T1)が、表
面前方部74Aの肉厚T2(図11参照)におけるブロ
ーアップ比(T0/T2)に比べて大きく、肉厚が薄い
という問題がある。However, as shown in FIG.
In the conventional example as shown in FIG. 13, the parison 70A is used.
Among the parts, the amount of expansion is different between the part that expands toward the front surface forming mold 80A and the part that expands toward the back surface forming mold 80B with the dividing surface 82 as a boundary, and thus the difference in wall thickness variation amount. Occurs. That is, in the portion of the back surface portion 75 excluding the connection portion 76 and the front surface rear portion 74B,
Thickness T0 of parison 70A before expansion (see Fig. 13)
The blow-up ratio (T0 / T1), which is the ratio of the wall thickness T1 of the bumper beam 70 after expansion (see FIG. 11) to the blow-up ratio (T0 / T1) at the wall thickness T2 of the front surface portion 74A (see FIG. 11) ( There is a problem that it is larger and thinner than T0 / T2).
【0014】また、薄肉部が形成されることで、剛性が
低くなり、衝撃試験である5MPHペンデュラム試験に
合格しないという問題がある。そして、剛性を向上させ
るためには薄肉部の肉厚を厚くしなければならないが、
一部分の肉厚を厚くすることは困難であり、全体的に厚
肉となってしまうため軽量化が図れないという問題があ
る。また、このような厚肉化により、材料費が高くなっ
てしまうという問題がある。Further, since the thin portion is formed, the rigidity becomes low, and there is a problem that it does not pass the 5MPH pendulum test which is an impact test. And, in order to improve the rigidity, it is necessary to increase the thickness of the thin portion,
There is a problem that it is difficult to increase the thickness of a part of the wall, and since the wall thickness is increased as a whole, the weight cannot be reduced. Further, there is a problem in that the material cost becomes high due to such thickening.
【0015】本発明の目的は、ブロー成形時の偏肉を抑
えて薄肉部の発生を防ぐとともに、軽量化と剛性の向上
との両方を満足できるバンパービームの製造方法および
その金型を提供することにある。An object of the present invention is to provide a method for manufacturing a bumper beam and a die for the bumper beam, which can suppress uneven thickness at the time of blow molding to prevent a thin portion from being generated, and can satisfy both weight reduction and rigidity improvement. Especially.
【0016】[0016]
【課題を解決するための手段】本発明の方法は、前記偏
肉が金型の分割面と成形品形状との相対位置バランスに
より生じるという知見に達し、この知見に基づいて金型
の分割面の位置を変更することによって前記目的を達成
しようとするものである。具体的には、断面形状が表面
側に配置される表面部と、この表面部よりも後方に配置
される裏面部とを備え、前記表面部の両端が前記裏面部
の両端に向かって延びてこれらの両端にそれぞれ接続さ
れ、かつ前記裏面部の中間部分の一部が少なくとも前記
表面部近傍に達するように突出配置された形状である二
重壁構造のバンパービームを形成するために、内部にキ
ャビティを有する分割金型内に筒状のパリソンを挟み込
んでブロー成形するバンパービームの製造方法であっ
て、前記金型の分割面を前記キャビティのうち前記表面
部と前記裏面部との接続位置に対応する部位の近傍を通
るように設けておき、前記パリソンの長手方向両端およ
び長手方向に沿った両側部分を前記分割面で挟み込み、
このパリソン内部に空気を吹き込むことを特徴とする。The method of the present invention has reached the finding that the uneven thickness is caused by the relative positional balance between the dividing surface of the mold and the shape of the molded product, and based on this finding, the dividing surface of the mold is reached. It is intended to achieve the above-mentioned object by changing the position of. Specifically, the cross-sectional shape includes a front surface portion arranged on the front surface side and a rear surface portion arranged rearward of the front surface portion, and both ends of the front surface portion extend toward both ends of the rear surface portion. In order to form a double-walled bumper beam which is connected to both ends thereof and has a shape in which a part of an intermediate portion of the back surface portion is projectingly arranged to reach at least the vicinity of the front surface portion, A method for manufacturing a bumper beam in which a cylindrical parison is sandwiched and blow-molded in a split mold having a cavity, wherein a split surface of the mold is located at a connection position between the front surface portion and the back surface portion of the cavity. It is provided so as to pass in the vicinity of the corresponding part, and both ends in the longitudinal direction of the parison and both side parts along the longitudinal direction are sandwiched by the dividing surfaces,
It is characterized by blowing air into the parison.
【0017】また、前記バンパービームの製造方法にお
いて、前記金型の分割面を当該金型のキャビティ内面の
うち前記裏面部の両端部分を形成する面と同一面上に設
けておくとともに、前記パリソンをその中心軸線が前記
分割面に沿うように前記金型間に導入し、前記パリソン
の直径方向に対向する両側部分を前記分割面に挟み込む
ことを特徴とする。In the method for manufacturing the bumper beam, the split surface of the mold is provided on the same surface as the inner surface of the cavity of the mold that forms both end portions of the back surface portion, and the parison is formed. Is introduced between the molds so that the central axis of the parison is along the dividing surface, and both side portions of the parison facing in the diametrical direction are sandwiched between the dividing surfaces.
【0018】一方、本発明の金型は、断面形状が、表面
側に配置される表面部と、この表面部よりも後方に配置
される裏面部とを備え、前記表面部の両端は前記裏面部
の両端に向かって延びてこれらの両端にそれぞれ接続さ
れ、かつ前記裏面部の一部が少なくとも前記表面部近傍
に達するように突出配置された二重壁構造を有するバン
パービームのブロー成形用金型であって、分割面が内部
のキャビティ内面のうち前記表面部と前記裏面部との接
続位置に対応する部位の近傍を通るように設けられたこ
とを特徴とする。On the other hand, the mold of the present invention has a cross-sectional shape including a front surface portion disposed on the front surface side and a rear surface portion disposed rearward of the front surface portion, and both ends of the front surface portion are the rear surface. Blow molding gold for a bumper beam having a double wall structure extending toward both ends of the portion and connected to both ends thereof, and projectingly arranged so that a part of the back surface portion reaches at least the vicinity of the front surface portion. The mold is characterized in that the dividing surface is provided so as to pass in the vicinity of a portion corresponding to a connection position between the front surface portion and the back surface portion on the inner surface of the cavity.
【0019】また、前記ブロー成形用金型において、前
記分割面は当該金型のキャビティ内面のうち前記裏面部
の両端部分を形成する面と同一面上に設けられたことを
特徴とする。Further, in the blow molding die, the dividing surface is provided on the same plane as a surface forming both end portions of the back surface portion in the cavity inner surface of the die.
【0020】[0020]
【作用】このような本発明においては、分割位置よりも
表面部側と裏面部側とでパリソンの膨張量が略均一とな
るような位置に金型の分割面を設けるので、膨張箇所に
よる表裏各側のブローアップ比の差異が少なくなり、バ
ンパービームは断面の肉厚の均一性が向上する。また、
薄肉部を形成しないのでバンパービームの剛性が向上す
るとともに、肉厚を厚くする必要がないため軽量とな
り、材料費の削減になる。以上により、前記目的が達成
される。In the present invention as described above, since the dividing surface of the mold is provided at a position where the expansion amount of the parison is substantially uniform on the front surface side and the rear surface side with respect to the dividing position, the front and back sides depending on the expansion location. The difference in blow-up ratio on each side is reduced, and the uniformity of the wall thickness of the bumper beam is improved. Also,
Since the thin portion is not formed, the rigidity of the bumper beam is improved, and since it is not necessary to increase the thickness, the weight is reduced and the material cost is reduced. By the above, the said objective is achieved.
【0021】そして、金型の分割面をキャビティ内面の
うちバンパービーム裏面部の両端部分を形成する面と同
一面上に設けることで、金型の構造が簡易となり、製作
等が容易となる。さらに、パリソンをその中心軸線を分
割面に沿うように金型間に導入し、パリソンの直径方向
に対向する両側部分を前記分割面で挟み込むように金型
の型締めを行うことで、表裏各側のブローアップ比の差
異がさらに少なくなり、肉厚の均一性がより向上する。By providing the dividing surface of the mold on the same surface as the inner surface of the cavity which forms both end portions of the back surface of the bumper beam, the structure of the mold is simplified and the manufacture is facilitated. Furthermore, by introducing the parison between the molds so that the central axis of the parison is along the dividing surface, and clamping the mold so that both side portions facing the diametrical direction of the parison are sandwiched between the dividing surfaces, The difference in blow-up ratio on the side is further reduced, and the uniformity of wall thickness is further improved.
【0022】[0022]
【実施例】以下、本発明の一実施例を図面に基づいて説
明する。図1には、本発明に係る製造方法によって得ら
れる樹脂製のバンパービーム10の長手方向の略中央に
おける長手方向直交断面の構造が示されている。この
際、バンパービーム10は図10に示した従来例のバン
パービーム70と略同形状の本体を有しており、図1に
示した本実施例の断面形状と図11の断面形状とは基本
的に同様である。このためここでは外観の図示と本体の
説明を省略する。An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the structure of the resin bumper beam 10 obtained by the manufacturing method according to the present invention in a cross section in the longitudinal direction substantially at the center in the longitudinal direction. At this time, the bumper beam 10 has a main body having substantially the same shape as the bumper beam 70 of the conventional example shown in FIG. 10, and the sectional shape of the present embodiment shown in FIG. 1 and the sectional shape of FIG. Is the same. Therefore, the illustration of the external appearance and the description of the main body are omitted here.
【0023】図1において、バンパービーム10は断面
形状においてその表面側に表面部11を備え、この表面
部11よりも裏面側に裏面部12を備えている。また、
表面部11の両端は裏面部12の両端に向かって延びて
これらの両端にそれぞれ接続されている。そして、裏面
部12の一部は表面側に突出配置された突出部12Aと
なっており、この突出部12Aの先端部分は表面部11
に密着して接続部13を形成している。さらに、表面部
11と裏面部12とによって仕切られた中空部14を形
成している。In FIG. 1, the bumper beam 10 has a front surface portion 11 on the front surface side and a back surface portion 12 on the back surface side with respect to the front surface portion 11 in a sectional shape. Also,
Both ends of the front surface portion 11 extend toward both ends of the back surface portion 12 and are connected to these both ends, respectively. A part of the back surface portion 12 is a projection portion 12A that is arranged so as to project toward the front surface side, and the tip portion of this projection portion 12A is the front surface portion 11.
And the connection portion 13 is formed. Further, a hollow portion 14 partitioned by the front surface portion 11 and the back surface portion 12 is formed.
【0024】図2には、本発明に係るバンパービーム1
0の製造に使用するブロー成形用の金型20の断面が示
されており、この断面はバンパービーム10の長手方向
の略中央に対応す部分の長手方向直交断面である。図2
において、金型20はバンパービーム10の表面部11
を形成する表面部形成用型20Aと裏面部12を形成す
る裏面部形成用型20Bとを備え、各々を型締め状態と
した際にその内部に形成される断面略C字形のキャビテ
ィー21を備えている。FIG. 2 shows a bumper beam 1 according to the present invention.
0 shows a cross section of a blow-molding die 20 used for manufacturing 0. This cross section is a cross section orthogonal to the longitudinal direction of a portion corresponding to substantially the center of the bumper beam 10 in the longitudinal direction. Figure 2
At the mold 20, the mold 20 is attached to the surface portion 11 of the bumper beam 10.
Is provided with a front surface forming die 20A for forming a back surface portion and a back surface forming die 20B for forming a back surface portion 12, and a cavity 21 having a substantially C-shaped cross section is formed inside each of them when they are clamped. I have it.
【0025】キャビティー21の内面のうち、裏面部1
2の両端部分を形成する面と同一面上には、金型20を
表面部形成用型20Aと裏面部形成用型20Bとに分割
する分割面22が設けられている。キャビティー21の
内面には、バンパービーム10の表面部11を形成する
表面部形成面23と裏面部12を形成する裏面部形成面
24とが設けられ、この裏面部形成面24には、その略
中央部が表面部形成面23の近傍に向かって突出してい
る裏面部突出部面24Aが形成されている。Of the inner surface of the cavity 21, the back surface portion 1
A split surface 22 is provided on the same surface as the surfaces forming both end portions of 2 to divide the die 20 into a front surface forming die 20A and a back surface forming die 20B. An inner surface of the cavity 21 is provided with a front surface forming surface 23 that forms the front surface 11 of the bumper beam 10 and a back surface forming surface 24 that forms the back surface 12. The back surface forming surface 24 has A rear surface protruding portion surface 24A is formed such that a substantially central portion thereof protrudes toward the vicinity of the front surface forming surface 23.
【0026】このような本実施例においては、以下のよ
うな製造方法に従ってバンパービーム10が製造され
る。この際、従来例の製造方法と本実施例の製造方法と
の違いはブロー成形時のパリソン10Aの導入位置およ
び使用する金型の違いであり、簡略化のため従来例との
相違点について以下に説明する。In this embodiment, the bumper beam 10 is manufactured according to the following manufacturing method. At this time, the difference between the manufacturing method of the conventional example and the manufacturing method of the present embodiment is the difference in the introduction position of the parison 10A and the mold used during blow molding. For simplification, the differences from the conventional example are as follows. Explained.
【0027】パリソン10Aの導入位置の違いは、図3
(A)、(B)に示すように、パリソン10Aの中心軸線P
0が表面部形成用型20Aおよび裏面部形成用型20B
のそれぞれの分割面の位置P1およびP2に沿うように
パリソン10Aを位置させることであり、型締めは、分
割面の位置P1およびP2でパリソン10Aの直径方向
に対向する両側部分A1、A2(図2および図3(A)参
照)を挟み込むように行われる。金型の違いは、図13
(A)〜(C)に示した従来の金型80を図3(A)〜(C)に
示した本発明に係る金型20に置き換えることである。The difference in the introduction position of the parison 10A is shown in FIG.
As shown in (A) and (B), the central axis P of the parison 10A is
0 is the front surface forming die 20A and the back surface forming die 20B.
Is to position the parison 10A along the positions P1 and P2 of the respective dividing planes, and the mold clamping is performed at the positions P1 and P2 of the dividing planes on both side portions A1 and A2 which are diametrically opposed to the parison 10A (FIG. 2 and FIG. 3 (A)). Figure 13 shows the difference between the molds.
The conventional die 80 shown in FIGS. 3A to 3C is replaced with the die 20 according to the present invention shown in FIGS.
【0028】図2に戻って、金型20内でのパリソン1
0Aの成形状態は次のようになる。図2(A)には金型2
0の型締めが完了する直前の状態が、図2(B)には直後
の状態がそれぞれ示されている。図2(A)において、金
型20の挟み込みが進むにつれて、パリソン10Aのう
ち裏面部形成用型20Bと対向する面の一部が裏面部突
出部面24Aによって長手方向に連続するように挟み込
み方向へ押し込まれる。Returning to FIG. 2, the parison 1 in the mold 20.
The molding state of 0A is as follows. The mold 2 is shown in FIG.
The state immediately before the completion of mold clamping 0 is shown, and the state immediately after that is shown in FIG. 2 (B). In FIG. 2 (A), as the sandwiching of the die 20 progresses, a part of the surface of the parison 10A facing the back surface forming die 20B is sandwiched by the back surface projecting surface 24A so as to be continuous in the sandwiching direction. Is pushed into.
【0029】図2(B)において、挟み込みが完了する時
点では、裏面部突出部面24Aによって押し込まれた部
分は、表面部形成用型20Aと対向する面の内面と密着
して接続部13を形成する。また、この挟み込みが完了
する際に、パリソン10Aの両側の部分は長手方向に沿
って表面部形成用型20Aと裏面部形成用型20Bとの
分割面22の間に挟み込まれる。In FIG. 2B, at the time when the sandwiching is completed, the portion pressed by the back surface protruding portion surface 24A comes into close contact with the inner surface of the surface facing the front surface forming die 20A and the connection portion 13 is formed. Form. When this sandwiching is completed, the parts on both sides of the parison 10A are sandwiched along the longitudinal direction between the dividing surfaces 22 of the front surface forming die 20A and the back surface forming die 20B.
【0030】さらに、表面部成形用型20Aの長手方向
の上方に設けられた吹き込み口(図3の符号85参照)
から、パリソン10Aのそれぞれの中空部14に空気を
吹き込む。すると、パリソン10Aはその肉厚を減じな
がら矢印の方向に膨張してキャビティ21の内面に密着
し、これによりバンパービーム10として形成される。Further, a blowing port provided above the front surface molding die 20A in the longitudinal direction (see reference numeral 85 in FIG. 3).
From this, air is blown into each hollow portion 14 of the parison 10A. Then, the parison 10 </ b> A expands in the direction of the arrow while reducing the thickness thereof and adheres closely to the inner surface of the cavity 21, whereby the bumper beam 10 is formed.
【0031】このような本実施例によれば、以下のよう
な効果がある。すなわち、パリソン10Aのうち分割面
22を境としてキャビティ21の表面部形成面23に向
かって膨張する部分と裏面部形成面24に向かって膨張
する部分とは、互いに膨張量の差が少なく肉厚の変移量
が略等しくなるので、膨張部分のブローアップ比を略同
じくすることができ、表面部11の肉厚T3(図1参
照)と裏面部12の肉厚T4(図1参照)との差を少な
くすることができる。According to this embodiment, the following effects are obtained. That is, in the parison 10A, the portion that expands toward the front surface forming surface 23 and the portion that expands toward the rear surface forming surface 24 of the cavity 21 with the dividing surface 22 as a boundary have a small difference in expansion amount from each other, and are thick. The blow-up ratios of the inflated portions can be made substantially the same, and the wall thickness T3 of the front surface portion 11 (see FIG. 1) and the wall thickness T4 of the back surface portion 12 (see FIG. 1) can be made equal to each other. The difference can be reduced.
【0032】また、薄肉部が形成されないので剛性が向
上し、肉厚を厚くすることなく5MPHペンデゥラム試
験に合格することができる。そして、薄肉部が生じない
ことで、従来のようにあえて肉厚を厚くする必要がない
ので軽量化が図れ、材料費を削減することができる。Further, since the thin portion is not formed, the rigidity is improved and the 5MPH pendulum test can be passed without increasing the thickness. Further, since the thin wall portion is not generated, it is not necessary to increase the wall thickness as in the conventional case, so that the weight can be reduced and the material cost can be reduced.
【0033】さらに、金型20の分割面22はキャビテ
ィ21の内面のうち裏面部12の両端部分を形成する面
と同一面上に設けられているので、金型が簡易なものと
なり金型の製作費用を削減することができる。また、型
合わせや取り付け等の段取り時間が短縮されるととも
に、バリが角部に位置するのでその除去作業が容易とな
り作業効率がよくなるとともに、外観も良好となる。Furthermore, since the dividing surface 22 of the mold 20 is provided on the same surface as the inner surface of the cavity 21 that forms both ends of the back surface portion 12, the mold becomes simple and the mold is The production cost can be reduced. Further, the setup time such as mold matching and mounting is shortened, and since the burr is located at the corner portion, the work of removing the burr is facilitated, the work efficiency is improved, and the appearance is also improved.
【0034】そして、表面部成形用型20Aおよび裏面
部成形用型20Bのそれぞれの分割面の位置P1、P2
はパリソン10Aの中心軸線P0の位置になるように金
型20の型締めが行われるので、パリソン10Aの各半
周分で表面部11と裏面部12とがそれぞれ形成される
ことになり、膨張前の表面部11と裏面部12とは等長
となる。これにより、バンパービームの長手方向の略中
間部分でのブローアップ比の差異をさらに少なくするこ
とができ、肉厚の均一性をより向上させることができ
る。Positions P1 and P2 of the respective divided surfaces of the front surface molding die 20A and the back surface molding die 20B.
Since the mold 20 is clamped so as to be positioned on the central axis P0 of the parison 10A, the front surface portion 11 and the back surface portion 12 are formed in each half circumference of the parison 10A. The front surface portion 11 and the back surface portion 12 have the same length. As a result, it is possible to further reduce the difference in blow-up ratio in the substantially middle portion of the bumper beam in the longitudinal direction, and to further improve the uniformity of wall thickness.
【0035】なお、本発明の効果を確かめるために、以
下のような5MPHペンデュラム試験による比較実験を
行った。本発明のバンパービームとして、前記実施例の
金型および製造方法によってバンパービーム10を製造
した。これに対する比較例として、前記従来例(図10
〜12参照)によるバンパービーム70を製造した。In order to confirm the effect of the present invention, a comparative experiment by the following 5MPH pendulum test was conducted. As the bumper beam of the present invention, the bumper beam 10 was manufactured by the mold and manufacturing method of the above-described embodiment. As a comparative example to this, the conventional example (see FIG.
Bumper beam 70 according to
【0036】また、実施例および比較例のバンパービー
ムの材質は、それぞれメルトインデックス0.5g/1
0分、エチレン含量1.5重量%、アイソタクチックペ
ンタッド分率96モル%のブロックポリプロピレン(ブ
ロックPP)を70重量%と、メルトインデックス0.
03g/10分の高密度ポリエチレン(HDPE)を2
0重量%と、平均粒径1.5μm、平均アスペクト比1
5のタルクを10重量%とを含む樹脂組成物を用い、さ
らに、以下に示す成形条件で製品長さ1.6mのバンパ
ービームを成形した。Further, the material of the bumper beam of each of the examples and the comparative examples has a melt index of 0.5 g / 1.
0 minutes, ethylene content 1.5% by weight, isotactic pentad fraction 96 mol% block polypropylene (block PP) 70% by weight, melt index 0.
2 g of high density polyethylene (HDPE) 03g / 10 min
0% by weight, average particle size 1.5 μm, average aspect ratio 1
Using a resin composition containing 10% by weight of talc of No. 5, a bumper beam having a product length of 1.6 m was further molded under the following molding conditions.
【0037】成形条件 成形機スクリュー :90mmφ ダイ :100mmφ アキュームレーター :25リットル 型締圧力 :60ton スクリュー回転数 :40rpm モーター負荷 :115AMolding conditions Molding machine screw: 90 mmφ Die: 100 mmφ Accumulator: 25 liters Mold clamping pressure: 60 ton Screw rotation speed: 40 rpm Motor load: 115 A
【0038】温度条件 シリンダー No.1:230℃ No.2:210℃ No.3:190℃ No.4:190℃ クロスヘッドNo.1:190℃ No.2:190℃ No.3:190℃ ダイス No.1:190℃ No.2:190℃ 成形サイクル :230sec 金型温度 :28℃ 樹脂温度 :225℃Temperature conditions Cylinder No. 1: 230 ° C. No. 2: 210 ° C. No. 3: 190 ° C. No. 4: 190 ° C. Crosshead No. 1: 190 ° C. No. 2: 190 ° C. No. 3: 190 ° C. Die No. 1: 190 ° C. No. 2: 190 ° C Molding cycle: 230sec Mold temperature: 28 ° C Resin temperature: 225 ° C
【0039】また、5MPHペンデュラム試験には図4
および図5に示される衝撃試験装置を用いた。即ち、衝
撃試験装置30は図4に示すように所定の圧力を所定速
度(8km/Hr=5mile/Hr)で印加できる一
般の衝撃試験装置から構成され、この衝撃試験装置30
の下方の押圧面31の中央には、ポール取付具32を介
して押圧ポール33が取付けられている。この押圧ポー
ル33は外径が7インチで長さが所定の長さとされた円
柱から構成され、ポール取付具32は、図5に詳細に示
すように、板状体32Aと2本の軸32Bとにより構成
されている。そして、被試験バンパービーム10をH型
鋼からなる取付台34に取り付け、被試験バンパービー
ム10の長手方向中央に押圧ポール33を当接させて、
衝撃試験装置30で圧下して行う。Further, the 5MPH pendulum test is shown in FIG.
And the impact test apparatus shown in FIG. 5 was used. That is, the impact test apparatus 30 is composed of a general impact test apparatus capable of applying a predetermined pressure at a predetermined speed (8 km / Hr = 5 miles / Hr) as shown in FIG.
A pressing pole 33 is attached to the center of the lower pressing surface 31 via a pole fitting 32. The pressing pole 33 is composed of a cylinder having an outer diameter of 7 inches and a predetermined length, and the pole attachment 32 includes a plate-shaped body 32A and two shafts 32B as shown in detail in FIG. It is composed of and. Then, the bumper beam 10 to be tested is attached to the mounting base 34 made of H-shaped steel, and the pressing pole 33 is brought into contact with the center of the bumper beam 10 to be tested in the longitudinal direction,
The impact tester 30 performs the reduction.
【0040】本比較実験では、実施例のバンパービーム
10と比較例のバンパービーム70とをそれぞれ許容変
形量40mmに圧縮した後、それぞれの外観の目視検査
を行った。表1に実験結果を示す。In this comparative experiment, the bumper beam 10 of the example and the bumper beam 70 of the comparative example were each compressed to an allowable deformation amount of 40 mm and then visually inspected. Table 1 shows the experimental results.
【0041】[0041]
【表1】 [Table 1]
【0042】実験結果によれば、実施例では何ら異常が
認められなかったのに対して、比較例では薄肉部および
金型の分割面に対応する位置にクラックが認められた。
これにより、実施例は比較例に比べて優れていることが
わかり、本発明の効果が顕著に示された。According to the experimental results, no abnormality was found in the examples, whereas in the comparative example, cracks were found at the positions corresponding to the thin portion and the divided surface of the mold.
From this, it was found that the example was superior to the comparative example, and the effect of the present invention was remarkably shown.
【0043】なお、本発明は前記実施例に限定されるも
のではなく、本発明の目的を達成できる範囲内で他の構
成を含み、以下に示すような変形等も本発明に含まれ
る。即ち、前記実施例では、金型20の分割面22はキ
ャビティ21の表面のうち裏面部12の両端部分を形成
する面と同一面上に設けられていたが、例えば、図6
(A)に示すように分割面22は裏面部12の両端部を形
成する面と平行であってこの面よりも裏面側に配置され
てもよく、図6(B)に示すように表面側に突出配置され
てもよい。The present invention is not limited to the above embodiments, but includes other configurations within the scope of achieving the object of the present invention, and the following modifications and the like are also included in the present invention. That is, in the above-described embodiment, the dividing surface 22 of the mold 20 is provided on the same surface as the surface forming the both ends of the back surface portion 12 of the surface of the cavity 21, but, for example, as shown in FIG.
As shown in FIG. 6A, the dividing surface 22 may be parallel to the surfaces forming both ends of the back surface portion 12 and may be arranged on the back surface side of this surface. As shown in FIG. It may be arranged to project.
【0044】また、図6(C)に示すように表面部11の
両端部を形成する面と同一面上に設けられても、金型2
0の分割面22と成形品形状との相対位置バランスが保
たれるので、成形品の肉厚は均一となる。要するに、キ
ャビティ21の表面のうち表面部11と裏面部12との
接続位置に対応する部位の近傍を通るように設けられて
いればよい。しかし、分割面22をキャビティ21の表
面のうち裏面部11の両端部分を形成する面と同一面上
に設けておくことで、金型が容易となるので好ましい。Further, as shown in FIG. 6 (C), even if it is provided on the same surface as the surface forming both ends of the surface portion 11, the mold 2
Since the relative position balance between the divided surface 22 of 0 and the shape of the molded product is maintained, the wall thickness of the molded product becomes uniform. In short, it suffices that the cavity 21 is provided so as to pass through the vicinity of the portion corresponding to the connection position between the front surface portion 11 and the back surface portion 12 of the cavity 21. However, it is preferable to provide the dividing surface 22 on the same surface of the surface of the cavity 21 as the surface forming both end portions of the back surface portion 11 because the mold becomes easier.
【0045】前記実施例では、パリソン10Aの中心軸
線P0を分割面の位置P1、P2に沿うように金型間に
導入し、パリソン10Aの直径方向に対向する両側部分
を挟み込むように金型20の型締めを行っているが、中
心軸線P0が分割面の位置P1、P2に沿わない場合で
あっても本発明に含まれる。しかし、そうすることでブ
ローアップ比の差異がさらに少なくなり、肉厚の均一性
がより向上するので好ましい。In the above-described embodiment, the center axis P0 of the parison 10A is introduced between the molds along the positions P1 and P2 of the dividing plane, and the mold 20 is sandwiched between the diametrically opposite side portions of the parison 10A. Although the mold clamping is performed, the present invention includes the case where the central axis P0 does not lie along the positions P1 and P2 of the dividing surface. However, by doing so, the difference in the blow-up ratio is further reduced, and the uniformity of the wall thickness is further improved, which is preferable.
【0046】そして、金型20の材質は、金属であれば
任意であるが、アルミニウム、亜鉛合金、鋳鉄、鋼鉄、
ベリリウム銅合金などが適している。また、パリソン1
0Aを挟み切る部分は金型の摩耗が激しいので、別に硬
い焼き入れ鋼でつくった部品をはめ込んでもよい。The material of the mold 20 may be any metal as long as it is aluminum, zinc alloy, cast iron, steel,
Beryllium copper alloy is suitable. Also, parison 1
Since the mold wears severely at the part where 0A is sandwiched, a part made of hardened hardened steel may be fitted separately.
【0047】また、前記実施例では、バンパービーム1
0の裏面部12はこの一部が表面部11に密着するよう
に突出配置されているが、例えば、図7に示すように裏
面部12の一部は表面部11の近傍に突出配置されたも
のであってもよく、密着している必要はない。しかし、
密着していることでバンパービーム10の機械的強度が
向上するので好ましい。In the above embodiment, the bumper beam 1
The back surface portion 0 of 0 is arranged so as to project so that a part thereof comes into close contact with the front surface portion 11. For example, as shown in FIG. 7, a part of the back surface portion 12 is arranged so as to project near the front surface portion 11. It does not have to be in close contact with each other. But,
The close contact improves the mechanical strength of the bumper beam 10, which is preferable.
【0048】そして、前記実施例では、表面部11の断
面形状は略C字形となっているが、図8(A)〜(C)に示
すようにコ字形、V字形、U字形等であってもよい。ま
た、裏面部12の両端部は平面に限定されるものではな
く、例えば図8(D)〜(F)に示すような曲面状であって
も、2つ以上の面から形成されてもよい。さらに、突出
部12Aの形状は、図8(G),(H)に示すように先端部
が鋭角であったり、あるいは先端が開口部よりも幅広な
形状であってもよい。In the above embodiment, the cross-sectional shape of the surface portion 11 is substantially C-shaped, but as shown in FIGS. 8 (A) to 8 (C), it is U-shaped, V-shaped, U-shaped or the like. May be. Further, both end portions of the back surface portion 12 are not limited to flat surfaces, and may have a curved surface shape as shown in FIGS. 8D to 8F or may be formed from two or more surfaces. . Further, the shape of the protrusion 12A may be such that the tip has an acute angle as shown in FIGS. 8G and 8H, or the tip has a wider width than the opening.
【0049】要するに、表面部11、裏面部12および
接続部12Aの形状は、成形後の肉厚が均一となるよう
に金型の分割面との相対位置バランスが保たれるならば
任意に決められてよい。さらにまた、バンパービーム1
0の長手方向に形成されるリブ構造は、図9(A)、(B)
に示すように多数列配置されてもよく、あるいは不連続
なリブ構造が千鳥状に配置されてもよい。In short, the shapes of the front surface portion 11, the rear surface portion 12 and the connecting portion 12A are arbitrarily determined as long as the relative position balance with the dividing surface of the mold is maintained so that the thickness after molding is uniform. You may be taken. Furthermore, bumper beam 1
The rib structure formed in the longitudinal direction of 0 is shown in FIGS.
May be arranged in multiple rows, or discontinuous rib structures may be arranged in a staggered manner.
【0050】そして、バンパービーム10の材質は、従
来より一般に使用されている熱可塑性樹脂の中から任意
に選ぶことができる。特に、ブロー成形する場合の成形
加工性およびバンパービーム10の物性である剛性、耐
衝撃性、ピンチオフ強度等の機械的強度の点で、メルト
インデックス1.0g/10分以下、アイソタクチック
ペンタッド分率93モル%以上のプロピレン単独重合体
またはメルトインデックス1.0g/10分以下、エチ
レン単位含有量15重量%以下、プロピレンホモ重合部
のアイソタクチックペンタッド分率93モル%以上のプ
ロピレン−エチレン共重合体50〜99重量%と、エチ
レン系樹脂またはエチレン系ゴム1〜30重量%と、平
均粒子径10μm以下、平均アスペクト比3〜20のタ
ルク1〜30重量%とから成る樹脂組成物が好適であ
る。The material of the bumper beam 10 can be arbitrarily selected from the thermoplastic resins generally used conventionally. In particular, in terms of molding processability in blow molding and mechanical strength such as rigidity, impact resistance, and pinch-off strength, which are physical properties of the bumper beam 10, a melt index of 1.0 g / 10 minutes or less, an isotactic pentad. Propylene homopolymer having a fraction of 93 mol% or more or melt index of 1.0 g / 10 min or less, ethylene unit content of 15 wt% or less, and isotactic pentad fraction of a propylene homopolymer part of 93 mol% or more- Resin composition comprising 50 to 99% by weight of ethylene copolymer, 1 to 30% by weight of ethylene resin or ethylene rubber, and 1 to 30% by weight of talc having an average particle size of 10 μm or less and an average aspect ratio of 3 to 20. Is preferred.
【0051】また、この組成物にはさらに所望に応じ、
無水マレイン酸変性ポリオレフィン、アクリル酸変性ポ
リオレフィンのような熱可塑性樹脂や、炭酸カルシウ
ム、マイカ、ガラス繊維、炭素繊維のような無機充てん
剤や、酸化防止剤、紫外線防止剤、滑剤、難燃剤、着色
剤等の各種添加剤を含有させてもよい。Also, if desired, the composition may further comprise
Thermoplastic resins such as maleic anhydride-modified polyolefin and acrylic acid-modified polyolefin, inorganic fillers such as calcium carbonate, mica, glass fiber and carbon fiber, antioxidants, UV inhibitors, lubricants, flame retardants, coloring Various additives such as agents may be contained.
【0052】また、前記実施例では、中空部14に空気
を吹き込むための吹き込み口85は表面部成形用型20
Aの外面の前面部であって長手方向の上方に設けられて
いるが、吹き込み口85の位置は成形されるバンパービ
ームの形状によって任意に決められてよく、適宜な数で
あってよい。Further, in the above-mentioned embodiment, the blowing port 85 for blowing air into the hollow portion 14 has the surface portion molding die 20.
Although it is provided on the front surface of the outer surface of A and above in the longitudinal direction, the position of the blowing port 85 may be arbitrarily determined depending on the shape of the bumper beam to be molded, and may be an appropriate number.
【0053】さらに、バンパービーム10の両端に配置
された車体取り付け用のボルト73(図10参照)の数
量は、3本に限定されるものではなく、要求される取り
付け強度等によって適宜決められてよい。そして、この
ボルトはバンパービームと一体成形される必要はなく、
バンパービーム側に配置される必要はない。例えば、バ
ンパービーム側にボルト穴を設け、この穴にボルトを通
して車体に取り付ける方法であってよく、また、車体側
にボルトを配置することによって取り付ける方法であっ
てもよい。要するに、バンパービームが車体に取り付け
ばよい。Further, the number of vehicle body mounting bolts 73 (see FIG. 10) arranged at both ends of the bumper beam 10 is not limited to three, but may be appropriately determined according to the required mounting strength and the like. Good. And this bolt does not have to be integrally molded with the bumper beam,
It need not be located on the bumper beam side. For example, a method may be used in which a bolt hole is provided on the bumper beam side and a bolt is passed through this hole to attach the bolt to the vehicle body, or a bolt hole may be placed on the vehicle body side to attach the bolt hole. In short, the bumper beam should be attached to the vehicle body.
【0054】[0054]
【発明の効果】以上に述べたように本発明によれば、金
型の分割面と製品形状との相対位置バランスが保たれ、
バンパービームの断面の肉厚は均一となるので、肉厚を
厚くすることなく5MPHペンデュラム試験に合格する
ことができるうえ、軽量化と剛性の向上とを同時に満足
するバンパービームを得ることができるという効果があ
る。As described above, according to the present invention, the relative position balance between the dividing surface of the mold and the product shape is maintained,
Since the thickness of the bumper beam is uniform in the cross section, it is possible to pass the 5MPH pendulum test without increasing the thickness and to obtain a bumper beam that satisfies both weight reduction and rigidity at the same time. effective.
【図1】本発明の一実施例によって得られるバンパービ
ームを示す断面図。FIG. 1 is a cross-sectional view showing a bumper beam obtained according to an embodiment of the present invention.
【図2】前記実施例の中間部断面を示す断面図。FIG. 2 is a sectional view showing a cross section of an intermediate portion of the embodiment.
【図3】前記実施例のバンパービームのブロー成形の工
程を説明する説明図。FIG. 3 is an explanatory view explaining a blow molding process of the bumper beam of the embodiment.
【図4】前記実施例に基づくバンパービームの衝撃試験
状態を示す側面図。FIG. 4 is a side view showing a bumper beam impact test state according to the embodiment.
【図5】前記図5の衝撃試験装置に用いられる押圧ポー
ル部の概略構成を示す斜視図。5 is a perspective view showing a schematic configuration of a pressure pole portion used in the impact test device of FIG.
【図6】本発明の変形例の要部を示す断面図。FIG. 6 is a sectional view showing a main part of a modified example of the present invention.
【図7】本発明の他の変形例の中間部断面を示す断面
図。FIG. 7 is a cross-sectional view showing a cross section of an intermediate portion of another modification of the present invention.
【図8】本発明の更に他の変形例の中間部断面を示す断
面図。FIG. 8 is a cross-sectional view showing a cross section of an intermediate portion of still another modification of the present invention.
【図9】本発明で成形される他のバンパービームの中間
部断面を示す断面斜視図。FIG. 9 is a sectional perspective view showing a middle section of another bumper beam molded by the present invention.
【図10】従来例のバンパービームを示す全体斜視図。FIG. 10 is an overall perspective view showing a bumper beam of a conventional example.
【図11】前記従来例のバンパービームの中間部断面を
示す断面図。FIG. 11 is a cross-sectional view showing a cross section of an intermediate portion of the bumper beam of the conventional example.
【図12】前記従来例のバンパービームの製造に用いら
れるブロー成形用金型を示す断面図。FIG. 12 is a cross-sectional view showing a blow molding die used for manufacturing the bumper beam of the conventional example.
【図13】前記従来例のバンパービームのブロー成形の
工程を説明する説明図。FIG. 13 is an explanatory view for explaining a blow molding process of the bumper beam of the conventional example.
10 バンパービーム 10A パリソン 11 裏面部 12 表面部 12A 突出部 20 金型 21 キャビティー 22 分割面 P0 中心軸線 P1、P2 分割面の位置 10 Bumper beam 10A Parison 11 Back surface 12 Front surface 12A Projection 20 Mold 21 Cavity 22 Dividing surface P0 Center axis P1, P2 Position of dividing surface
Claims (4)
と、この表面部よりも後方に配置される裏面部とを備
え、前記表面部の両端が前記裏面部の両端に向かって延
びてこれらの両端にそれぞれ接続され、かつ前記裏面部
の中間部分の一部が少なくとも前記表面部近傍に達する
ように突出配置された形状である二重壁構造のバンパー
ビームを形成するために、内部にキャビティを有する分
割金型内に筒状のパリソンを挟み込んでブロー成形する
バンパービームの製造方法であって、 前記金型の分割面を前記キャビティのうち前記表面部と
前記裏面部との接続位置に対応する部位の近傍を通るよ
うに設けておき、前記パリソンの長手方向両端および長
手方向に沿った両側部分を前記分割面で挟み込み、この
パリソン内部に空気を吹き込むことを特徴とするバンパ
ービームの製造方法。1. A cross-sectional shape includes a front surface portion disposed on the front surface side and a rear surface portion disposed rearward of the front surface portion, and both ends of the front surface portion extend toward both ends of the rear surface portion. To form a double-walled bumper beam which is connected to both ends of the bumper and has a shape in which a part of an intermediate portion of the back surface portion is projectingly arranged so as to reach at least the vicinity of the front surface portion. A method for manufacturing a bumper beam in which a cylindrical parison is sandwiched and blow-molded in a split mold having a cavity, wherein a split surface of the mold is formed at a connection position between the front surface portion and the back surface portion of the cavity. It is provided so as to pass through the vicinity of the part corresponding to, and both ends in the longitudinal direction of the parison and both side parts along the longitudinal direction are sandwiched by the dividing surfaces, and air is blown into the parison. Method for manufacturing a bumper beam according to symptoms.
造方法において、前記金型の分割面を当該金型のキャビ
ティ内面のうち前記裏面部の両端部分を形成する面と同
一面上に設けておくとともに、前記パリソンをその中心
軸線が前記分割面に沿うように前記金型間に導入し、前
記パリソンの直径方向に対向する両側部分を前記分割面
に挟み込むことを特徴とするバンパービームの製造方
法。2. The method of manufacturing a bumper beam according to claim 1, wherein the dividing surface of the mold is provided on the same surface as a surface forming both end portions of the back surface part in the cavity inner surface of the mold. In addition, the parison is introduced between the molds so that the central axis of the parison is along the dividing surface, and both side portions of the parison facing in the diametrical direction are sandwiched between the dividing surfaces. Method.
と、この表面部よりも後方に配置される裏面部とを備
え、前記表面部の両端は前記裏面部の両端に向かって延
びてこれらの両端にそれぞれ接続され、かつ前記裏面部
の一部が少なくとも前記表面部近傍に達するように突出
配置された二重壁構造を有するバンパービームのブロー
成形用金型であって、 分割面が内部のキャビティ内面のうち前記表面部と前記
裏面部との接続位置に対応する部位の近傍を通るように
設けられたことを特徴とするブロー成形用金型。3. The cross-sectional shape comprises a front surface portion arranged on the front surface side and a rear surface portion arranged rearward of the front surface portion, and both ends of the front surface portion extend toward both ends of the rear surface portion. A blow mold for blow molding of a bumper beam having a double-walled structure connected to both ends of each of them and protruding so that a part of the back surface reaches at least the vicinity of the front surface. Is provided so as to pass through the vicinity of a portion of the inner surface of the inner cavity corresponding to the connection position of the front surface portion and the back surface portion.
おいて、前記分割面は当該金型のキャビティ内面のうち
前記裏面部の両端部分を形成する面と同一面上に設けら
れたことを特徴とするブロー成形用金型。4. The blow molding die according to claim 3, wherein the dividing surface is provided on the same plane as a surface forming both end portions of the back surface portion in the cavity inner surface of the die. Characteristic blow molding die.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP17238094A JP3510675B2 (en) | 1994-07-25 | 1994-07-25 | Manufacturing method of bumper beam |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP17238094A JP3510675B2 (en) | 1994-07-25 | 1994-07-25 | Manufacturing method of bumper beam |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH0834052A true JPH0834052A (en) | 1996-02-06 |
JP3510675B2 JP3510675B2 (en) | 2004-03-29 |
Family
ID=15940844
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP17238094A Expired - Fee Related JP3510675B2 (en) | 1994-07-25 | 1994-07-25 | Manufacturing method of bumper beam |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP3510675B2 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1097793A1 (en) * | 1999-11-08 | 2001-05-09 | Visteon UK Limited | Method and apparatus for blow moulding articles with internal walls |
US20130323454A1 (en) * | 2012-05-31 | 2013-12-05 | Metelix Products Inc. | Reinforced Blow Moulded Vehicle Running Board and Method of Making Same |
JP2018103368A (en) * | 2016-12-22 | 2018-07-05 | 日本プラスト株式会社 | Blow molding |
-
1994
- 1994-07-25 JP JP17238094A patent/JP3510675B2/en not_active Expired - Fee Related
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1097793A1 (en) * | 1999-11-08 | 2001-05-09 | Visteon UK Limited | Method and apparatus for blow moulding articles with internal walls |
US20130323454A1 (en) * | 2012-05-31 | 2013-12-05 | Metelix Products Inc. | Reinforced Blow Moulded Vehicle Running Board and Method of Making Same |
US9676338B2 (en) * | 2012-05-31 | 2017-06-13 | Metelix Products Inc. | Reinforced blow moulded vehicle running board and method of making same |
JP2018103368A (en) * | 2016-12-22 | 2018-07-05 | 日本プラスト株式会社 | Blow molding |
Also Published As
Publication number | Publication date |
---|---|
JP3510675B2 (en) | 2004-03-29 |
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