This application is related to and claims priority from Japanese patent applications Nos. 2012-187345 and 2012-194298 incorporated herein by reference.
1. Field of the Invention
The present invention relates to a structure for attaching an insert member by embedding at least one portion of the insert member in an outer wall of a blow molded article, which can be particularly applied to an insert member for attaching the same to an automobile fuel tank formed by blow molding.
2. Description of Related Art
A filler tube for injecting fuel into an automobile fuel tank is attached thereto. Conventionally, such an automobile fuel tank has been made of metals, but, recently, a fuel tank made of a thermoplastic synthetic resin has been also used, because it can effect lightweight vehicle bodies, no rust is generated therein, and it can be readily formed into a desired configuration.
And, a fuel tank as a blow molded article formed by blow molding has been used, because it can be readily produced. As shown in
In one conventional example, as shown in
With this structure, a welding surface of the welding seat 18 is flat so that sufficient welding of the welding seat 18 is not effected without preheating the welding surface of the tube attaching member 14 to elevated temperatures. And, a welding margin is thin so that it is difficult to obtain a sufficient welding strength of the welding seat 18 against loads in drawing, bending, and rotating directions, which are applied from an exterior side of the fuel tank 16 to the tube attaching member 14. In addition, the tube attaching member 14 is welded to the fuel tank 16 merely with the welding surface of the welding seat 18 so that it is difficult to obtain a sufficient welding strength against loads in bending and rotating directions.
Accordingly, it is an object of the present invention to provide an attaching structure of an insert member to an outer wall of a blow molded article by embedding the insert member therein, which is readily produced and exhibits a great holding strength against the insert member.
According to a first aspect of the present invention, in an attaching structure of an insert member for attaching the insert member to an outer wall of a blow molded article by embedding at least one part of the insert member therein, the insert member includes a cylinder part adapted to penetrate the outer wall of the blow molded article, and a flange part protruding from an exterior surface of the cylinder part in a width direction thereof, the flange part is embedded in the outer wall of the blow molded article, and includes a plurality of through holes, a parison is flowed into the plurality of through holes during blow molding to fusion-bond both surfaces of the flange part with the parison such that the parison is hardened to define a flange cover part integrally formed with an outer wall of the insert member, thereby holding the flange part.
In the first aspect of the present invention, in an attaching structure of an insert member for attaching the insert member to an outer wall of a blow molded article by embedding at least one part of the insert member therein, the insert member includes a cylinder part adapted to penetrate the outer wall of the blow molded article, and a flange part protruding from an exterior surface of the cylinder part in a width direction thereof. Therefore, by embedding the flange part in the outer wall of the blow molded article, the cylinder part is attached to the blow molded article to define an opening of the blow molded article. Liquid or gas can be injected into or discharged from the blow molded article by way of the opening.
The flange part is embedded in the outer wall of the blow molded article, and includes a plurality of through holes, a parison is flowed into the plurality of through holes during blow molding to fusion-bond both surfaces of the flange part with the parison such that the parison is hardened to define a flange cover part integrally formed with the outer wall of the insert member, thereby holding the flange part. Therefore, the parison flowed into the plurality of through holes can hold both surfaces of the flange part strongly, and both surfaces of the flange part are fusion-bonded with the parison during blow molding to hold the flange part. Consequently, the fusion-bonding area between the flange part and the flange cover part becomes large to increase the fusion-bonding strength. In addition, after the parison is hardened, the flange part is embedded in the outer wall of the blow molded article, and is held with the flange cover part integrally formed with the outer wall of the blow molded article so that the flange part can be strongly held furthermore. Therefore, if loads in drawing, bending, and rotating directions are applied to the cylinder part, the insert member can be securely held.
According to a second aspect of the present invention, the plurality of through holes are provided in the flange part at equal intervals circumferentially.
In the second aspect of the present invention, the plurality of through holes are provided in the flange part at equal intervals circumferentially so that the parison homogeneously fills around the flange part entirely, and after the parison is hardened, the flange cover part can securely and strongly hold the flange part over the entire circumference thereof.
According to a third aspect of the present invention, the plurality of through holes are formed to have an elliptical or circular shape.
In the third aspect of the present invention, the plurality of through holes are formed to have an elliptical or circular shape so that the parison can flow into the plurality of through holes smoothly. In the case of an elliptical shape, the amount of the parison flowing into the through holes is large so that the exterior surface and the interior surface of the flange part can be strongly held with the flange cover part defined with the hardened parison. In the case of a circular shape, many holes can be formed along a periphery of the flange part so that the flange part can be held uniformly.
According to a fourth aspect of the present invention, the cylinder part of the insert member includes an outside cylinder part projecting outside the blow molded article, and an inside cylinder part projecting inside the blow molded article, and an inside cylinder cover part is fusion-bonded to an exterior surface of the inside cylinder part.
In the fourth aspect of the present invention, the cylinder part of the insert member includes an outside cylinder part projecting outside the blow molded article, and an inside cylinder part projecting inside the blow molded article, and an inside cylinder cover part is fusion-bonded to an exterior surface of the inside cylinder part. Therefore, the parison is fusion-bonded to the insert member in not only the flange part but also the inside cylinder part so that the holding strength against the insert member increases, and consequently, if loads in drawing, bending, and rotating directions are applied to the outside cylinder part, the insert member can be securely held.
According to a fifth aspect of the present invention, protruding linear parts are provided in the flange part or the inside cylinder part, and at least a tip end of the protruding linear part is fusion-bonded to the flange cover part or the inside cylinder cover part.
In the fifth aspect of the present invention, protruding linear parts are provided in the flange part or the inside cylinder part, and at least a tip end of the protruding linear part is fusion-bonded to the flange cover part or the inside cylinder cover part. The tip end of the protruding linear part is readily heated with the parison and readily melted so as to be fusion-bonded to the parison. After the parison is hardened, the tip end of the protruding linear part bites in the flange cover part or the inside cylinder cover part and is fixed thereto, thereby improving the sealing properties. In addition, the protruding linear part is readily heated so that the temperature for preheating the entire body of the insert member can be lowered, or the preheating process can be omitted, whereby the deformation of the insert member due to the lowering of the rigidity can be prevented.
According to a sixth aspect of the present invention, the protruding linear parts include a plurality of protruding linear parts formed in an interior surface of the flange part circumferentially, and at least a tip end of each protruding linear part is fusion-bonded to the flange cover part.
In the sixth aspect of the present invention, the protruding linear parts include a plurality of protruding linear parts formed in an interior surface of the flange part circumferentially, and at least a tip end of each protruding linear part is fusion-bonded to the flange cover part so that the protruding linear parts in the interior surface of the flange part are melted with the parison and bite thereinto, and after the parison is solidified, the flange cover part and the protruding linear parts in the interior surface of the flange part are welded to each other, thereby improving the sealing properties against the outer wall of the blow molded article.
According to a seventh aspect of the present invention, the protruding linear parts include a plurality of protruding linear parts formed in an exterior surface of the inside cylinder part circumferentially, and at least a tip end of each protruding linear part is fusion-bonded to the inside cylinder cover part.
In the seventh aspect of the present invention, the protruding linear parts include a plurality of protruding linear parts formed in an exterior surface of the inside cylinder part circumferentially, and at least a tip end of each protruding linear part is fusion-bonded to the inside cylinder cover part. In the case where the protruding linear parts are formed in the exterior surface of the inside cylinder part circumferentially, the protruding linear parts are melted with the parison to be welded thereto, and after the parison is hardened, the sealing properties between the inside cylinder cover part and the exterior surface of the inside cylinder part are improved.
According to an eighth aspect of the present invention, the protruding linear part is formed in a tip end surface of the inside cylinder part circumferentially, and at least a tip end of each protruding linear part is fusion-bonded to a cover end part extending from the inside cylinder cover part integrally therewith and adapted to cover the tip end surface of the inside cylinder part.
In the eighth aspect of the present invention, the protruding linear part is formed in a tip end surface of the inside cylinder part circumferentially, and at least a tip end of each protruding linear part is fusion-bonded to a cover end part extending from the inside cylinder cover part integrally therewith and adapted to cover the tip end surface of the inside cylinder part. Where the protruding linear part is formed in a tip end surface of the inside cylinder part circumferentially, the protruding linear part is melted with the parison and is fusion-bonded thereto, and after the parison is hardened, the cover end part extending from the inside cylinder cover part integrally therewith and adapted to cover the tip end surface of the inside cylinder part is fixed to the tip end of the protruding linear part to improve the sealing properties against the tip end surface of the inside cylinder part.
According to a ninth aspect of the present invention, the tip end of the protruding linear part has a triangular sectional shape, a trapezoidal sectional shape, a circular sectional shape, or an elliptical sectional shape.
In the ninth aspect of the present invention, the tip end of the protruding linear part has a triangular sectional shape, a trapezoidal sectional shape, a circular sectional shape, or an elliptical sectional shape. Where the tip end of the protruding linear part has a triangular sectional shape, the triangular tip end is readily melted with the parison so that the protruding linear part is securely fusion-bonded to the parison. Where the tip end of the protruding linear part has a trapezoidal sectional shape, the trapezoidal tip end is readily melted with the parison so that the fusion-bonding area between the protruding linear part and the parison increases, whereby the protruding linear part is strongly fusion-bonded to the parison. Where the tip end of the protruding linear part has a circular or elliptical sectional shape, the circular or elliptical tip end is melted with the parison so that an arc-shaped region of the protruding linear part, which is adapted to be fusion-bonded to the parison, enters the parison, whereby the protruding linear part is strongly fusion-bonded to the parison.
According to a tenth aspect of the present invention, the insert member has a recessed part adapted to be charged with a parison on an exterior side of the flange part.
In the tenth aspect of the present invention, the insert member has a recessed part adapted to be charged with a parison on an exterior side of the flange part so that the parison can securely enter around a base of the flange part, and an end of the parison entering the exterior side of the flange part can be held with the recessed part to securely and strongly hold the flange part.
According to an eleventh aspect of the present invention, the blow molded article is an automobile fuel tank, and the insert member is a tube attaching member for attaching a tube adapted to inject and discharge liquid or gas into and from the automobile fuel tank, to the automobile fuel tank.
In the eleventh aspect of the present invention, the blow molded article is an automobile fuel tank, and the insert member is a tube attaching member for attaching a tube adapted to inject and discharge liquid or gas into and from the automobile fuel tank, to the automobile fuel tank. With this arrangement, the tube attaching member exhibits an improved strength to securely hold the tube, the sealing properties between the automobile fuel tank and the tube attaching member are improved to prevent the leakage of fuel and fuel vapor.
The flange part is embedded in the outer wall of the blow molded article, and includes a plurality of through holes, a parison is flowed into the plurality of through holes during blow molding to fusion-bond both surfaces of the flange part with the parison such that after the parison is hardened, a flange cover part is integrally formed with the outer wall of the insert member to hold the flange part. Therefore, the parison flowed into the plurality of through holes can strongly hold the flange part, and both surfaces of the flange part are fusion-bonded and held with the flange cover part so that the fusion-bonding area between the flange part and the flange cover part enlarges to increase the fusion-bonding strength. Since the flange part is held with the flange cover part formed using the hardened parison, if a drawing load is applied to the cylinder part, or loads are applied from the outside of the blow molded article in bending and rotation directions, the insert member can be securely held.
Other objects, features, and characteristics of the present invention will become apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification.
The present invention will be explained based on an attaching structure in which a tube attaching member is attached to an outer wall of a fuel tank, for example, but the present invention can be widely applied to the case in which an insert member is attached to any blow molded article other than the fuel tank.
Embodiments of the present invention will be explained with reference to
First, a first embodiment will be explained with reference to
As shown in
In the case of a plurality of layers, layers having high rigidity and layers having low fuel permeability can be combined with each other.
In the case of a plurality of layers, for example, a center layer is composed of a fuel permeation preventing barrier layer of an ethylene vinyl alcohol copolymer (EVOH) or nylon, adhesive layers of modified polyethylene are formed on upper and lower sides of the barrier layer, and outer layers of a high density polyethylene (HDPE) are formed on exterior sides of the adhesive layers.
In the upper portion of the outer wall 28, the tube attaching member 26 and a tank attaching portion 30 adapted to attach the tube attaching member 26 shown in
In addition, in the upper portion of the outer wall 28, a breather port attaching portion 32 is provided. The breather port attaching portion 32 is adapted to attach a breather hose (not shown) for releasing a gas from an interior of the fuel tank 24 to an exterior thereof during fuel supply. And reference numeral 33 designates a cut off valve adapted to prevent fuel leakage from the fuel tank 24 when an automobile overturns.
In an upper surface of the outer wall 28, hose clamps adapted to hold various hoses such as a fuel transfer hose may be provided. The present invention can be applied to these breather port attaching portion 32 and pipe and hose attaching members such as hose clamps, etc., similarly to the tube attaching member 26.
In the upper surface of the outer wall 28, an opening 34 is further provided, and a sub-tank 36 is attached on an inner surface of a lower portion of the outer wall 28 from the opening 34. The opening 34 is closed with a lid 38, and the lid 38 is screwed around the opening 34 with a lock plate 39. A seal ring 40 is attached between the opening 34 and the lid 38 to provide a seal therebetween.
And a fuel pump unit 42 is attached in an interior of the sub-tank 36. The sub-tank 36 is provided such that the fuel pump unit 42 can securely feed fuel from the fuel tank 24 to an engine when a vehicle is inclined or vibrated. The fuel pump unit 42 is attached to the lid 38 for performing repair and maintenance. A pipe extends from the fuel pump unit 42 and is connected to a fuel main port attaching portion 44 provided in the lid 38 in the upper portion of the outer wall 28. A fuel pipe (not shown) adapted to transfer fuel to the engine is attached to the fuel main port attaching portion 44.
As shown in
Next, the tube attaching member 26 in the first embodiment will be explained with reference to
The tube attaching member 26 is formed by injection molding separately from the fuel tank 24. The material thereof is composed of a fuel oil-resistant thermoplastic synthetic resin. A synthetic resin such as polyethylene, polypropylene, polyacetal, polyamide, etc. can be used, for example, but such a material as to be weldable to the parison 46 used upon blow molding.
The tube attaching member 26 as an insert member includes a cylinder part adapted to penetrate the outer wall 28 of the fuel tank 24, and the flange part 58 protruding from an exterior surface of the cylinder part in the width direction thereof. The cylinder part includes an outside cylinder part 62 projecting from the outer wall 28 outwardly, and the inside cylinder part 50 projecting from the outer wall 28 inwardly. A protruding linear part 64 is formed in an outer periphery of the outside cylinder part 62 close to the flange part 58. When a tube is inserted in the outside cylinder part 62, the protruding linear part 64 acts as a stopper for a tip end of the inserted tube to hold the same.
When the blow molding is performed, the parison 46 adapted to form the outer wall 28 is fusion-bonded to an exterior surface of the inside cylinder part 50, and after the parison 46 is hardened, it defines the inside cylinder cover part 48. With this arrangement, the parison 46 is fusion-bonded to not only the flange part 58 of the tube attaching member 26 but also the inside cylinder part 50 thereof so that the tube attaching member 26 has a great holding strength, whereby if a drawing load, and loads in bending and rotating directions, etc. are applied from an exterior side of the outside cylinder part 62, it can securely hold the tube attaching member 26.
After the parison 46 is hardened, the inside cylinder cover part 48 is formed on the exterior surface of the inside cylinder part 50 so as to be welded thereto. The parison 46 is fusion-bonded to a tip end of the inside cylinder cover part 48 to define a cover end part 66 so as to cover a tip end of the inside cylinder part 50 continuously with the inside cylinder cover part 48. With this arrangement, the sealing properties between the outer wall 28 and the tube attaching member 26 are improved by virtue of the fusion-bonding of the tip end of the inside cylinder part 50 and the parison 46.
The flange part 58 is formed to protrude outwardly from the vicinity of a border between the outside cylinder part 62 and the inside cylinder part 50 into a disk-shaped configuration.
As shown in
Therefore, the parison 46 flowed into the flange holes 54 can cover both surfaces of the flange part 58, and the parison 46 covering both surfaces thereof is joined with the parison 46 existing in the flange holes 54 so that the flange part 58 can be strongly held, and since the both surfaces of the flange part 58 are fusion-bonded to the parison 46, the fusion-bonding area between the flange part 58 and the parison 46 is enlarged to increase the fusion-bonding strength between the outer wall 28 and the parison 46.
After the parison 46 is hardened furthermore, an exterior side of the flange part 58 can be covered with the flange cover upper part 56, whereas an interior side of the flange part 58 can be covered with the flange cover lower part 60 so that the flange part 58 is embedded inside the outer wall 28 of the fuel tank 24, whereby the flange part 58 is entirely held with the tank attaching portion 30 to further hold the flange part 58 strongly. Therefore, if a drawing load, and loads in bending and rotating directions, etc. are applied from the exterior side of the outside cylinder part 62, the tube attaching member 26 can be securely held.
A recessed part 68 into which the parison 46 is adapted to flow can be formed on the exterior side of the flange part 58 in the vicinity of a base thereof so as to extend circumferentially. With this arrangement, the parison 46 can be securely made to flow into the recessed part 68 provided at the base of the flange part 58 during blow molding. Therefore a tip end of the parison 46 flowing along an exterior surface of the flange part 58 and entering into the recessed part 68 can be held with the recessed part 68, whereby the base of the flange part 58 can be securely held with the outer wall 28 strongly.
A plurality of protruding linear parts 70 can be formed on an interior surface of the flange part 58. With this arrangement, the protruding linear parts 70 provided on the interior surface of the flange part 58 bite into the parison 46 during blow molding to strongly fix the interior surface of the flange part 58 and the flange cover lower part 60, thereby improving the sealing properties between the interior surface of the flange part 58 and the outer wall 28. As a result, a fuel vapor, etc. do not leak between the tube attaching member 26 and the outer wall 28. Alternatively, a single protruding linear part 70 will do.
Next, a second embodiment will be explained with reference to
In the second embodiment, flange holes 72 of a flange part 74 include eight elliptical holes extending circumferentially. A parison 76 existing on both surfaces of the flange part 74 is strongly joined to a flange cover upper part 78 and a flange cover lower part 80 of the outer wall 28 that is formed after hardening of the parison 76 by virtue of the eight flange holes 72 to strongly hold a tube attaching member 82 at eight places.
No protruding linear part is provided in the flange part 74, but since many flange holes 72 are formed, the holding force of the flange part 74 can be maintained.
As shown in
Next, third and fourth embodiments will be explained with reference to
In the third embodiment shown in
In the fourth embodiment shown in
The flange holes 96 may have any configuration other than circular and elliptical configurations.
Next, fifth through seventh embodiments will be explained with reference to
In the fifth embodiment, a plurality of protruding linear parts 102 are provided in an interior surface of a flange part 104. The protruding linear parts 102 contact the parison 46 during blow molding so that tip ends of the protruding linear parts 102 are melted with heat of the parison 46 to fusion-bond the protruding linear parts 102 and the parison 46 to each other.
After the parison 46 is hardened, an exterior surface of the flange part 104 can be covered with a flange cover upper part 106, whereas an interior surface of the flange part 104 can be covered with a flange cover lower part 108 so that the flange part 104 is embedded inside an outer wall 110 of a fuel tank 112, whereby the flange part 104 is entirely held with a tank attaching portion 114 to further hold the flange part 104 strongly. Therefore, if a drawing load, and loads in bending and rotating directions, etc. are applied to an outside cylinder part 116, a tube attaching member 118 can be securely held.
As a result, the interior surface of the flange part 104, and the flange cover lower part 108 are strongly fixed to each other, thereby improving the sealing properties between the interior side of the flange part 104 and the flange cover lower part 108, and consequently, a fuel vapor, etc. do not leak between the tube attaching member 118 and the outer wall 110. The protruding linear part 102 can be composed of a single protruding linear part or a plurality of protruding linear parts.
Where a plurality of protruding linear parts 102 are provided in the interior surface of the flange part 104, the protruding linear parts 102 are welded to the parison 46 so that the interior side of the flange part 104 is bonded to the parison 46, and after the parison 46 is hardened, the sealing properties between the interior side of the flange part 104 and the flange cover lower portion 108 are improved.
As shown in
First, as shown in
In the following explanations, 102(a) designates a protruding linear part on the side of a base of the flange part 104, whereas 102(b) designates a protruding linear part on the side of a tip end of the flange part 104.
In
Next, as shown in
And, as shown in
And, where, as shown in
Next, a sixth embodiment will be explained with reference to
In the sixth embodiment, protruding linear parts 124 are provided in an exterior surface of the tank inside cylinder part 122. As shown in
The protruding linear parts 124 may have sectional shapes equal to those shown in
And the protruding linear parts 124 may be provided at many places from a base to a tip end of the inside cylinder part 122, or around only the base, the tip end or about a center thereof. Alternatively, a single protruding linear part 124 may be provided.
Next, a seventh embodiment will be explained with reference to
In the seventh embodiment, protruding linear parts 132 are provided in a tip surface of a tank inside cylinder part 130. As shown in
The protruding linear parts 132 may have sectional shapes similar to those shown in
And, as shown in
Next, the method of attaching the tube attaching member 24 as an insert member to the outer wall 28 of a fuel tank as a blow-molded article will be explained with reference to
In order to attach the tube attaching member 26 to the outer wall 28 of the fuel tank, it is attached using a blow mold 136 when the fuel tank is formed by blow molding.
The blow mold 136 has a recessed part 138 adapted to fit the tank outside cylinder 62 of the tube attaching member 26. And a through hole 140 for slidably inserting a later-described blow pin 142 is provided at a bottom of the recessed part 138. The inside diameter of the tank outside cylinder 62 and that of the through hole 140 are formed equal to each other such that when the tank outside cylinder part 62 is fitted into the recessed part 138, the blow pin 142 can slide therein.
In order to attach the tube attaching member 26 to the outer wall 28, the tube attaching member 26 is first fitted into the recessed part 138 provided in an area adapted to form the opening 34 of the fuel tank 24. As a result, as shown in
Next, as shown in
Then, as shown in
Then, air is blown into an interior of the parison 46 without sliding the blow pin 142. As a result, the parison 46 is pressed against the cavity surface 144 of the blow mold 136 to form the outer wall 28 of the fuel tank 24. At this time, the parison 46 is in a molten state to melt the protruding linear parts 70 of the flange part 58 to fusion-bond the parison 46 thereto.
The parison 46 fusion-bonded to the flange part 58 flow through the flange holes 54 provided in the flange part 58 to reach the exterior surface of the flange part 58, and fill the recessed part 68 provided in the exterior side of the flange part 58. As a result, the entire portion of the flange part 58 can be covered with the parison 46.
After blow molding, the blow pin 142 slides inside the tank inside cylinder part 50 and the tank outside cylinder part 62 to move backwards to the through hole 140 of the blow mold 136.
As a result, in the outer wall 28 formed by hardening of the parison 46, the exterior and interior surfaces of the flange part 53 are covered with the parison 46 so as to be joined with the flange holes 54, thereby strongly holding the tube attaching member 26.
Next, the produced fuel tank 24 is removed from the blow mold 136 to finish blow molding.
With the above-described method, the tube attaching member 26 can be attached to the outer wall 28 of the fuel tank 24 simultaneously with blow molding of the fuel tank 24.
While the invention has been described in connection with what are considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.