JP2006027367A - Fuel tank of metal and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel tank made of metal capable of lessening the leak of fuel at a part between the exterior wall portion near a through-hole and an accessory component, and manufacturable at low cost. <P>SOLUTION: The exterior wall 11 of a tank body 1 is furnished with a first 13 and a second convex 14 assuming concentric circles centering on the through-hole 12. A concave 15 is formed between the two convexes 13 and 14. The concave 15 has fluidity and is filled with a barrier-nature resin excellent in the permeation hindering characteristic for the fuel. After filling, a flange 22 on a nipple 2 is pressed to the crests of the two convexes 13 and 14 and secured, and the barrier-nature resin is confined in the concave 15. The barrier-nature resin solidifies to become a permeation hindering member 5, which hinders the fuel having passed the through-hole 12 from leaking out upon passing between the exterior wall 11 and the flange 22. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a metal fuel tank whose tank body is made of metal and a method for manufacturing the same.

  In general, a metal fuel tank has a tank body having a metal outer wall portion and accessory parts such as a nipple attached to the outer wall portion of the tank body. A through hole penetrating the outer wall of the tank body is formed. On the other hand, the accessory has a flange portion having a diameter larger than that of the through hole, and is attached to the outer wall portion in a state in which the flange portion is in annular contact with the outer surface around the through hole of the outer wall portion.

  By the way, in such a metal fuel tank, there is a possibility that the gas of the fuel stored in the tank body leaks out from the through hole between the tank body and the flange portion. Therefore, an annular rubber packing is interposed between the outer wall portion and the flange portion, thereby preventing fuel leakage.

  Rubber packing has a low permeation-preventing property for fuel gas. For this reason, the conventional metal fuel tank has a problem that a relatively large amount of fuel leaks from between the accessory part and the outer wall near the through hole.

  In order to solve such a problem, it is conceivable to increase the outer diameter of the packing or to use a packing made of fluorine rubber. In the former case, the flange portion is increased as the packing diameter is increased. However, there is a problem that the diameter must be increased. In the latter case, since fluororubber is expensive, there is a problem that the manufacturing cost of the fuel tank increases.

In order to solve the above problem, the present invention has a tank body having a metal outer wall portion in which a through hole is formed, and a contact portion larger than the through hole, and the contact portion is the through hole. A metal fuel tank provided with an accessory attached to the tank body in a state of annularly contacting the outer surface of the outer wall so as to surround the outer wall, and at least a contact surface between the outer wall and the contact portion An annular recess surrounding the through hole is formed on one side, and the recess is filled and solidified with a barrier resin having fluidity excellent in permeation-preventing property to the fuel, and the barrier resin is fixed to the outer wall and the contact. It is characterized by being brought into contact with the contact surface with the contact portion.
In this case, two annular convex portions surrounding the through hole are formed on at least one of the contact surfaces of the outer wall portion and the contact portion so as to be spaced apart from each other in the radial direction of the through hole. It is desirable to form the said recessed part between parts, and to contact | abut the other contact surface to the top part of said 2 convex part. In that case, it is desirable that the tops of the two convex portions are constituted by convex curved surfaces. Alternatively, it is desirable that the top portions of the two convex portions are constituted by a flat surface, and the intersection portion between the top portion and the side portion of the convex portion is constituted by a convex curved surface in contact with them.
Further, at least one of the contact surfaces of the outer wall portion and the contact portion is formed with three or more annular convex portions surrounding the through hole so as to be spaced apart from each other in the radial direction of the through hole. The concave portions are formed between two convex portions adjacent to each other in the radial direction, the barrier resin is filled in one concave portion, and a seal such as an O-ring is provided in the concave portion filled with the barrier resin. It is desirable to attach a member and make the other contact surface contact the top of each convex portion. In that case, it is desirable that the tops of the two convex portions adjacent to the concave portion filled with the barrier resin are constituted by a smooth convex curved surface. Alternatively, it is desirable that the top portions of the two convex portions are constituted by a flat surface, and the intersection portion between the top portion and the side portion of the convex portion is constituted by a convex curved surface in contact with them.
When the metal fuel tank according to claim 3 or 4 is manufactured, the barrier resin having fluidity is filled in the recess beyond its capacity, and then the outer wall portion and the contact portion are contacted. It can be produced by solidifying the barrier resin in a contact state.
When manufacturing the metal fuel tank according to claim 6 or 7, the barrier resin having fluidity is filled into the one recess beyond its capacity, and the recess inside the one recess is filled. It can be manufactured by mounting the seal member and then solidifying the barrier resin in a state where the outer wall portion and the contact portion are in contact with each other.

  According to the present invention having the above-described characteristic configuration, the barrier resin is accommodated in the recess, and the barrier resin is in contact with the outer surface of the tank body and the contact portion of the accessory part. It is possible to prevent the liquid and gas of the fuel from leaking through.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 shows a first embodiment of the present invention. The metal fuel tank according to this embodiment includes a tank body 1 and a nipple (accessory part) 2 attached to the tank body 1.

  The tank body 1 has an outer wall portion 11 made of a metal plate material. A through hole 12 extending from the outer surface to the inner surface is formed in the outer wall portion 11. The through hole 12 is formed in a circular cross section, but may be a quadrilateral or other desired shape. A first convex portion (convex portion) 13 that extends annularly along the through hole 12 is formed at the end of the outer wall portion 11 that faces the through hole 12. A second convex portion (convex portion) 14 is formed in an annular shape around the axial center of the through hole 12 at a location spaced a predetermined distance from the first convex portion 13 of the outer wall portion 11 radially outward of the through hole 12. ing. A portion of the outer wall portion 11 located between the second convex portion 14 and the first convex portion 13 is a concave portion 15. Of course, the recess 15 has an annular shape and is formed concentrically with the through hole 12. A plurality of male screw members 3 are fixed to the outer surface of the outer wall portion 11. Each male screw member 3 is concentric with the through hole 12 and is arranged on the circumference having a larger diameter than the through hole 12 at equal intervals in the circumferential direction.

  The nipple 2 is made of an inorganic material such as a barrier resin excellent in permeation-preventing property for fuel or a metal that does not allow fuel to permeate at all, and has a cylindrical main body 21 and a longitudinal direction of the main body 21. And a flange portion (contact portion) 22 provided integrally on the outer peripheral surface of the intermediate portion. The main body 21 is arranged concentrically with the through-hole 12 and with an inner circumferential surface of the through-hole 12 and an annular gap. The flange portion 22 has a disc shape and is formed concentrically with the main body portion 21. The outer diameter of the flange portion 22 is larger than the circumference where the male screw member 3 is arranged. The flange portion 22 abuts against the tops of the first and second convex portions 13 and 14. Thus, the nipple 2 is fixed to the outer wall portion 11, the recess 15 is closed by the flange portion 22, and the through-hole 12 is shielded by the nipple 2.

  The permeation blocking member 5 is filled in the concave portion 15 closed by the flange portion 22. The permeation blocking member 5 is made of a barrier resin that is excellent in permeation blocking performance for fuel. Among them, the recess 15 is made of a barrier resin that has fluidity when solidified, has a property of solidifying after a predetermined time, and has adhesiveness. Examples of such a barrier resin include an epoxy resin, a cyanoacrylate resin, and an acrylic resin.

  In the case of manufacturing the metallic fuel tank having the above structure, the first and second convex portions 13 and 14 and the concave portion 15 are formed in advance on the outer wall portion 11 of the tank body 1, and the concave portion 15 has fluidity. Is filled with a barrier resin. Thereafter, the flange portion 22 is pressed against the first and second convex portions 13 and 14 by the male screw member 3 and the female screw member 4 to fix the nipple 2 to the tank body 1, and the concave portion 15 is shielded by the flange portion 22. Then, the permeation | blocking prevention member 5 is formed when the barrier resin in the recessed part 15 solidifies.

  In the metal fuel tank manufactured in this way, the fuel that has passed between the inner peripheral surface of the through hole 12 and the outer peripheral surface of the main body portion 21 passes between the flange portion 22 and the outer wall portion 11. The permeation preventing member 5 made of a barrier resin prevents leakage to the outside. In addition, since the barrier resin has a high fuel permeation preventive property compared to a normal rubber packing, the size of the permeation preventive member 5 in the radial direction of the through hole 12 can be reduced. Accordingly, the flange portion 22 can be reduced in diameter. Furthermore, in this embodiment, since the resin having adhesiveness is used as the barrier resin, the permeation preventing member 5 is bonded to the outer wall portion 11 and the flange portion 22. Therefore, it is possible to prevent the fuel from leaking outside through the space between the outer wall portion 11 and the permeation prevention member 5 and between the flange portion 22 and the permeation prevention member 5.

  FIG. 2 shows a second embodiment of the present invention. In the metal fuel tank according to this embodiment, first, second, and third convex portions 16, 17, and 18 are formed on the outer wall portion 11. The first, second, and third convex portions 16, 17, and 18 are arranged concentrically around the through hole 12 and sequentially from the inner side to the outer side in the radial direction of the through hole 12. As shown in FIG. 3, the 2nd, 3rd convex parts 17 and 18 have comprised cross-sectional triangle shape, The top part is comprised by smooth convex curved surfaces, such as a circular arc surface. The top of the first convex part 16 is a flat surface whose height in the axial direction of the through hole 12 is the same as that of the second and third convex parts 18. However, a smooth convex curved surface such as an arc surface in contact with the top and the side surface is formed at the intersection between the flat top and the side surface of the first convex portion 18. Similarly to the tops of the second and third convex parts 17 and 18, the top part of the first convex part 16 may be constituted by a smooth convex curved surface. Conversely, the top portions of the second and third convex portions 17 and 18 may be flat, and the intersection between the top portion and the side surface may be constituted by a smooth convex curved surface in contact with them.

  Between the 1st convex part 16 and the 2nd convex part 17, the inner side recessed part (concave part inside one recessed part) 19 is formed, and between the 2nd convex part 17 and the 3rd convex part 18, An outer recess (one recess) 20 is formed. A seal member 6 made of an O-ring or the like is attached to the inner recess 19. The outer recess 20 is filled with the permeation blocking member 5. Other configurations are the same as those of the embodiment shown in FIG.

  When the metal fuel tank shown in FIG. 2 is manufactured, the seal member 6 is attached to the inner concave portion 19 and the outer concave portion 20 is filled with a fluid barrier resin 5 ′ (see FIG. 3). In this case, as shown in FIG. 3, the barrier resin 5 ′ has a liquid surface height of the top of the second and third protrusions 17 and 18 due to the viscosity or surface tension of the barrier resin 5 ′. So as to exceed the volume of the outer recess 20. Thereafter, the flange portion 22 is pressed against the tops of the first to third convex portions 16 to 18. Then, as shown in FIG. 4, a part of the barrier resin 5 ′ overflows from the second and third convex portions 17 and 18, which are the top portions of the flange portion 22 and the second and third convex portions 17 and 18. A thin film 7 is interposed therebetween. If this film 7 is in a state where the tops of the second and third convex parts 17 and 18 are bent, the flange part 22 is pressed against the tops of the second and third convex parts 17 and 18. Although it will be divided by the tops of the second and third convex parts 17 and 18, since the tops of the second and third convex parts 17 and 18 are actually constituted by smooth convex curved surfaces such as arcuate surfaces, It continues to be interposed between the flange portion 22 and the tops of the second and third convex portions 17 and 18. Therefore, the flange portion 22 is separated from the top portion of the first convex portion 16 by the thickness of the film 7 and is in direct contact with the top portions of the second and third convex portions 17 and 18. Without contact through the membrane 7. Of course, the membrane 7 is continuous with the permeation blocking member 5.

  According to the metal fuel tank manufactured as described above, the following effects can be obtained in addition to the effects of the fuel tank shown in FIG. That is, the barrier resin 5 ′ overflowing from the outer recessed portion 20 when pressing the flange portion 22 against the outer wall portion 11 is prevented by the seal member 6 from going beyond the inner recessed portion 19 toward the inner side. Accordingly, it is possible to prevent the barrier resin 5 ′ having fluidity from entering the tank body 1 through the through hole 12. Further, since the film 7 made of a barrier resin is interposed between the flange portion 22 and the top portions of the second and third convex portions 17 and 18, the flange portion 22 and the second and third convex portions 17 and 18 are interposed. The noise generated when the tank body 1 vibrates can be reduced as compared with the case where each of the tops directly contacts.

In addition, this invention is not limited to said embodiment, In the range which does not deviate from the summary, it can change suitably.
For example, in the above embodiment, the nipple 2 is used as an accessory attached to the tank body 1, but as an accessory attached to the tank body 1, in addition to the nipple 2, a valve sensor, a pump module, etc. is there.
Moreover, in said embodiment, the flange part 22 which makes a disk shape is formed in the nipple 2, and the end surface of this flange part 22 is made into the outer wall part 11 (the 1st, 2nd convex parts 13 and 14 of this, or 1st). 1, 2, 3 rd protrusions 16, 17, 18), but in the case of other accessory parts, the entire accessory part is made larger than the inner diameter of the through hole 12, and from the inner diameter of the through hole 12 A large end surface may be pressed against the outer wall portion 11.
Furthermore, in the above-described embodiment, the recesses 15; 19, 20 are formed in the outer wall portion 11, but may be formed in the flange portion 22 or both.

It is a longitudinal cross-sectional view which shows one embodiment of this invention. It is a longitudinal cross-sectional view which shows other embodiment of this invention. The expanded sectional view of the principal part which shows the state just before pressing a flange part on an outer wall part in embodiment shown in FIG. It is an expanded sectional view of the X circle part of Drawing 3 when a flange part is pressed on an outer wall part.

Explanation of symbols

1 Tank body 2 Nipple (accessory)
5 Permeation blocking member 5 'Barrier resin 11 Outer wall portion 12 Through hole 21 Flange portion (contact portion)
13 1st convex part (convex part)
14 Second convex part (convex part)
15 Concave portion 16 First convex portion (convex portion)
17 Second convex part (convex part)
18 3rd convex part (convex part)
19 Inner recess (recess inside the one recess)
20 Outer recess (one recess)

Claims (9)

A tank body having a metal outer wall portion with a through hole and a contact portion larger than the through hole, and the contact portion annularly contacts the outer surface of the outer wall portion so as to surround the through hole. In a metal fuel tank having an accessory attached to the tank body in contact with the tank body,
An annular recess that surrounds the through hole is formed in at least one of the contact surfaces of the outer wall and the contact portion, and this recess is filled with a barrier resin having fluidity that is excellent in preventing fuel from permeating. A metal fuel tank, wherein the barrier resin is brought into contact with a contact surface between the outer wall portion and the contact portion. Two annular convex portions surrounding the through hole are formed on at least one of the abutting surfaces of the outer wall portion and the abutting portion so as to be spaced apart from each other in the radial direction of the through hole, and between the two convex portions. 2. The metal fuel tank according to claim 1, wherein the concave portion is formed, and the other abutting surface is brought into contact with the top portions of the two convex portions. The metal fuel tank according to claim 2, wherein the tops of the two convex portions are formed by convex curved surfaces. 3. The metallic fuel according to claim 2, wherein the tops of the two convex parts are constituted by flat surfaces, and the intersections between the top parts and the side parts of the convex parts are constituted by convex curved surfaces in contact therewith. tank. Three or more annular convex portions surrounding the through hole are formed on at least one of the contact surfaces of the outer wall portion and the contact portion so as to be separated from each other in the radial direction of the through hole, and the radial direction of the through hole The recesses are respectively formed between two protrusions adjacent to each other, one of the recesses is filled with the barrier resin, and a sealing member such as an O-ring is provided in the recess inside the recess filled with the barrier resin. The metal fuel tank according to claim 1, wherein the metal fuel tank is mounted and the other abutment surface is abutted against the top of each convex portion. 6. The metallic fuel tank according to claim 5, wherein the tops of the two convex portions adjacent to the concave portion filled with the barrier resin are formed by convex curved surfaces. 6. The metallic fuel according to claim 5, wherein the top portions of the two convex portions are constituted by a flat surface, and the intersecting portion between the top portion and the side portion of the convex portion is constituted by a convex curved surface in contact therewith. tank. When manufacturing the metal fuel tank according to claim 3 or 4, the barrier resin having fluidity is filled in the concave portion beyond its capacity, and the outer wall portion and the contact portion are then contacted. A method for producing a metal fuel tank, characterized in that the barrier resin is solidified in a state of being allowed to stand. In manufacturing the metal fuel tank according to claim 6 or 7, the barrier resin having fluidity is filled in the one recess so as to exceed its capacity, and the recess is provided inside the one recess. A method of manufacturing a metal fuel tank, comprising: mounting a seal member; and then solidifying the barrier resin in a state where the outer wall portion and the contact portion are in contact with each other.

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