JP6771042B2 - Fuel tank - Google Patents

Description

The present invention relates to a fuel tank.

As a fuel tank mounted on an automobile or the like, the one described in Patent Document 1 is known. The fuel tank of Patent Document 1 has a form in which the entire area of the tank body is covered with a fiber reinforced resin layer.

Japanese Patent No. 5608287

However, the conventional fuel tank has a problem that the manufacturing cost increases because the amount of the fiber reinforced resin used is large.

The present invention has been created to solve such a problem, and an object of the present invention is to provide a fuel tank capable of reducing manufacturing costs.

In order to solve the above problems, the present invention has a plurality of reinforcements formed of a fiber reinforced resin on the outer surface of a tank body having a lower wall, an upper wall and a side wall and made of a thermoplastic resin including a barrier layer. A fuel tank integrally provided with a band member, wherein the reinforcing band member has a band shape and is continuously welded over the lower wall and the pair of side walls facing each other, and faces the upper wall. It is characterized in that it is continuously welded over the pair of the side walls.

According to such a configuration, the tank body can be efficiently reinforced by the reinforcing band member, and the amount of the fiber reinforced resin used can be reduced as compared with the conventional case, so that the manufacturing cost can be reduced.

Further, the outer surface of the tank body has a recess having a concave cross section, and the reinforcing band member is formed in the recess and has a bottom portion along the recess and a pair of side walls rising from both ends of the bottom portion. It is preferable to have.

According to such a configuration, the strength of the fuel tank can be synergistically increased.

Further, it is preferable that the reinforcing band member of the upper wall and the reinforcing band member of the lower wall are arranged so that their ends face each other at the central portion of the side wall. According to such a configuration, the tank body can be reinforced in a well-balanced manner.

Further, it is preferable that a plurality of the reinforcing band members are arranged side by side at intervals. According to such a configuration, the tank body can be reinforced more firmly.

Further, it is preferable to have a connection reinforcing band member that connects the adjacent reinforcing band members. According to such a configuration, the strength of the tank body can be partially increased.

Further, it is preferable that the side wall of the tank body has an arc shape protruding sideways. According to such a configuration, the strength of the side wall can be increased.

Further, corner reinforcements formed in the corners formed by the lower wall and the side wall adjacent to the lower wall, and the corners formed by the upper wall and the side wall adjacent to the upper wall, respectively. It is preferable to have a band member.

When a negative pressure is applied to the fuel tank, the side wall may buckle, but according to this configuration, the side wall can be efficiently reinforced.

The front Symbol reinforcing strap member is formed by laminating a plurality of fiber base and a plurality of resin films, the outermost layer of the reinforcing strip member, that is formed of a resin film thermoplastic preferable.

According to such a configuration, the weldability between the reinforcing band member and the tank body can be improved.

Further, it is preferable that the corner portion of the reinforcing band member is formed thicker than other portions. According to such a configuration, the strength of the corner portion can be increased while suppressing the manufacturing cost.

According to the fuel tank of the present invention, it is possible to efficiently reinforce and reduce the manufacturing cost.

It is a perspective view which shows the fuel tank which concerns on one Embodiment of this invention. FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a sectional view taken along line III-III of FIG. FIG. 6 is a sectional view taken along line IV-IV of FIG. It is an enlarged sectional view of a reinforcing band member and a recess. It is a perspective view which shows the reinforcement band member group (reinforcement band member, etc.) which concerns on 1st Embodiment. It is a perspective view which shows the laminated body forming process of the manufacturing method of the fuel tank which concerns on 1st Embodiment. It is the schematic sectional drawing which shows the reinforcement band member molding process of the manufacturing method of the fuel tank which concerns on 1st Embodiment. It is a perspective view which shows the reinforcement band member (lower reinforcement band member). It is the schematic sectional drawing which shows the arrangement process of the manufacturing method of the fuel tank which concerns on 1st Embodiment. It is the schematic sectional drawing which shows the fuel tank molding process of the manufacturing method of the fuel tank which concerns on 1st Embodiment. It is a perspective view which shows the fuel tank which concerns on 2nd Embodiment of this invention. It is the schematic sectional drawing which shows the modification of the laminate formation process. It is the schematic sectional drawing which shows the modification of the reinforcing band member.

Hereinafter, a fuel tank and a method for manufacturing the fuel tank according to the embodiment of the present invention will be described with reference to the drawings. In the following description, when referring to "front and back", "left and right", and "up and down", the direction shown in FIG. 1 is used as a reference. It should be noted that each direction is set for convenience in explaining the fuel tank T, and is not intended to limit the direction when the fuel tank T is mounted on the vehicle.

As shown in FIG. 1, the fuel tank T is mounted on a means of transportation such as an automobile, a motorcycle, and a ship, and is mainly composed of a tank body 1 and a reinforcing band member group 2. The shape of the fuel tank T is not limited to the form shown in FIG. 1, but in the present embodiment, the fuel tank T is formed so as to be symmetrical in the vertical, horizontal, and front-rear directions.

As shown in FIGS. 1 and 2, the tank body 1 is a hollow container for storing fuel such as gasoline, and is formed of, for example, a thermoplastic resin containing a barrier layer. The tank body 1 is molded by, for example, blow molding. The tank body 1 is composed of a lower wall 11, an upper wall 12, a first side wall 13, a second side wall 14, a third side wall 15, and a fourth side wall 16. The first side wall 13, the second side wall 14, the third side wall 15, and the fourth side wall 16 are portions constituting the peripheral wall of the tank body 1. The first side wall 13 and the second side wall 14 face each other substantially in parallel. Further, the third side wall 15 and the fourth side wall 16 face each other. The third side wall 15 and the fourth side wall 16 project in a semicircular shape toward the outer side. In the present embodiment, the lengths of the first side wall 13 and the second side wall 14 are shorter than the lengths of the third side wall 15 and the fourth side wall 16.

As shown in FIGS. 2 and 3, the lower wall 11, the upper wall 12, the third side wall 15 and the fourth side wall 16 of the tank body 1 are formed with recesses 3 that are continuous over the entire circumference. In this embodiment, four recesses 3 are arranged side by side in parallel in the front-rear direction with a gap. The recess 3 has a bottom portion and a pair of side walls rising from the bottom portion, and is formed so as to open to the outside. The recess 3 is formed with a constant cross section over the entire circumference. The number of recesses 3 is not limited.

As shown in FIGS. 1 and 4, continuous recesses 5 are formed in the lower wall 11, the first side wall 13 and the upper wall 12 of the tank body 1. In this embodiment, two recesses 5 are formed in the left-right direction. The recess 5 has a bottom portion and a pair of side walls rising from the bottom portion, and is formed so as to open to the outside. Further, the recess 5 is formed with a constant cross section over the entire length.

Further, as shown in FIG. 1, continuous recesses 6 are formed in the lower wall 11, the second side wall 14, and the upper wall 12 of the tank body 1. In this embodiment, two recesses 6 are formed in the left-right direction. The recess 6 has a bottom portion and a pair of side walls rising from the bottom portion, and is formed so as to open to the outside. Further, the recess 6 is formed with a constant cross section over the entire length.

As shown in FIGS. 1 and 6, the reinforcing band member group 2 is a member that reinforces the tank body 1 and is provided on the outer surface of the tank body 1. In the present embodiment, the reinforcing band member group 2 includes four lower reinforcing band members 21, four upper reinforcing band members 22, four lower angle reinforcing band members 23, and four upper angle reinforcing bands. It is composed of a member 24. The reinforcing band member group 2 is a thin band-shaped member formed of fiber-reinforced plastics (FRP), and is integrally formed on the outer surface of the tank body 1.

As shown in FIGS. 1 and 6, the four lower reinforcing band members (reinforcing band members) 21 are arranged side by side in parallel in the front-rear direction with a gap between the outer surfaces of the lower wall 11. Each lower reinforcing band member 21 is arranged and integrally formed in each recess 3 of the lower wall 11 of the tank body 1. The lower reinforcing band member 21 has a substantially U-shape in appearance. The lower reinforcing band member 21 is composed of a bottom portion 21a and side walls 21b and 21b rising from both sides of the bottom portion 21a in the front-rear direction (see also FIG. 5). That is, the lower reinforcing band member 21 is formed with a concave groove formed by the bottom portion 21a and the side walls 21b and 21b, and has a constant cross-sectional shape over the entire length. The lower reinforcing band member 21 is continuously arranged over the third side wall 15, the lower wall 11, and the fourth side wall 16.

As shown in FIGS. 1 and 6, the four upper reinforcing band members (reinforcing band members) 22 are arranged side by side in parallel in the front-rear direction with a gap between the outer surfaces of the upper wall 12. Each upper reinforcing band member 22 is arranged and integrally formed in each recess 3 of the upper wall 12 of the tank body 1. The upper reinforcing band member 22 has a substantially U-shape in appearance. The upper reinforcing band member 22 is composed of a bottom portion 22a and side walls 22b and 22b rising from both sides of the bottom portion 22a in the front-rear direction. That is, the upper reinforcing band member 22 is formed with a concave groove formed by the bottom portion 22a and the side walls 22b and 22b, and has a constant cross-sectional shape over the entire length. The upper reinforcing band member 22 is continuously arranged over the third side wall 15, the upper wall 12, and the fourth side wall 16. Further, the upper end portion of the lower reinforcing band member 21 and the lower end portion of the upper reinforcing band member 22 are arranged apart from each other on the third side wall 15. Further, the upper end portion of the lower reinforcing band member 21 and the lower end portion of the upper reinforcing band member 22 are arranged apart from each other on the fourth side wall 16.

As shown in FIGS. 1 and 6, two of the four lower angle reinforcing band members 23 are provided in the recesses 5 corresponding to the corners of the lower wall 11 and the first side wall 13, respectively. It is integrally formed. The lower corner reinforcing band member 23 has a substantially L-shape in appearance. The lower angle reinforcing band member 23 is composed of a bottom portion 23a and side walls 23b and 23b rising from both sides of the bottom portion 23a. That is, the lower angle reinforcing band member 23 is formed with a concave groove formed by the bottom portion 23a and the side walls 23b and 23b, and has a constant cross-sectional shape over the entire length. The other two lower corner reinforcing band members 23 are integrally formed in the recesses 6 corresponding to the corners of the lower wall 11 and the second side wall 14.

As shown in FIGS. 1 and 6, two of the four upper angle reinforcing band members 24 have the upper wall 12 and the recesses 5 corresponding to the corners of the first side wall 13, respectively. It is integrally formed. The upper corner reinforcing band member 24 has a substantially L-shape in appearance. The upper angle reinforcing band member 24 is composed of a bottom portion 24a and side walls 24b and 24b rising from both sides of the bottom portion 24a. That is, the upper corner reinforcing band member 24 has a concave groove formed in the bottom portion 24a and the side walls 24b and 24b, and has a constant cross-sectional shape over the entire length. The other two upper corner reinforcing band members 24 are integrally formed in the recesses 6 corresponding to the corners of the upper wall 12 and the second side wall 14.

Here, when the areas of the lower wall 11 and the upper wall 12 are larger than the areas of the first side wall 13 to the fourth side wall 16 as in the present embodiment, a positive pressure is applied to the fuel tank T. Then, a particularly large positive pressure tends to act on the lower wall 11 and the upper wall 12 of the tank body 1. On the other hand, when a negative pressure is applied to the inside of the fuel tank T, a particularly large negative pressure acts on the first side wall 13 and the second side wall 14, and the first side wall 13 and the second side wall 14 may buckle.

In the present embodiment, the four lower reinforcing band members 21 extending in the left-right direction of the lower wall 11 are installed, and the four upper reinforcing band members 22 extending in the left-right direction of the upper wall 12 are installed. Since it is installed, it can be efficiently reinforced especially against the positive pressure acting on the fuel tank T.

On the other hand, in the present embodiment, the lower angle reinforcing band members 23 and 23 are installed at the corners of the first side wall 13 and the lower wall 11, and the upper angle reinforcing band members 23 and 23 are installed at the corners of the first side wall 13 and the upper wall 12. Since 24 and 24 are installed, it is possible to efficiently reinforce the negative pressure acting on the first side wall 13. Further, lower angle reinforcing band members 23, 23 are installed at the corners of the second side wall 14 and the lower wall 11, and upper angle reinforcing band members 24, 24 are installed at the corners of the second side wall 14 and the upper wall 12. Therefore, in particular, it is possible to efficiently reinforce the negative pressure acting on the second side wall 14.

The reinforcing band member group 2 may be provided with at least a pair of a lower reinforcing band member 21 and an upper reinforcing band member 22. Further, the arrangement of the lower reinforcing band member 21 and the upper reinforcing band member 22 is not limited to this embodiment, and the design can be changed as appropriate. For example, the lower reinforcing band member 21 and the upper reinforcing band member 22 may be arranged so as to be staggered instead of corresponding positions. Further, the lower reinforcing band member 21 may be continuously arranged on the first side wall 13, the lower wall 11, and the second side wall 14. Further, the upper reinforcing band member 22 may also be continuously arranged on the first side wall 13, the upper wall 12, and the second side wall 14. Further, the lower reinforcing band member 21 and the upper reinforcing band member 22 may be arranged in a cross shape in a plan view.

Similarly, the lower angle reinforcing band member 23 and the upper angle reinforcing band member 24 may be arranged so as to be staggered instead of corresponding positions. The lower corner reinforcing band member 23 may be arranged at the corner between the lower wall 11 and the third side wall 15, or at the corner between the lower wall 11 and the fourth side wall 16. Further, the upper corner reinforcing band member 24 may be arranged at the corner portion between the upper wall 12 and the third side wall 15 or at the corner portion between the upper wall 12 and the fourth side wall 16. Further, the lower angle reinforcing band member 23 and the upper angle reinforcing band member 24 may be omitted. Further, the lower reinforcing band member 21, the upper reinforcing band member 22, the lower angle reinforcing band member 23, and the upper angle reinforcing band member 24 are all formed to have a concave cross section, but the cross section is semicircular, triangular, plate, etc. It may have the shape of.

Next, a method of manufacturing a fuel tank will be described. In the method for manufacturing a fuel tank, a laminate forming step, a reinforcing band member forming step, an arrangement step, and a fuel tank forming step are mainly performed.

As shown in FIG. 7, the laminate forming step is a step of superimposing a plurality of fiber base materials 31 and a plurality of resin films 32 to form a laminate 33. The fiber base material 31 is a thin sheet made of carbon fiber, glass fiber, resin fiber or the like. The fiber base materials 31 are laminated so that the orientation angles of the fibers are different. The resin film 32 is a thin film made of a thermoplastic resin (high density polyethylene, polyethylene, nylon, etc.) or a thermosetting resin (phenol resin, epoxy resin, etc.). The resin films 32 and 32 are laminated so as to sandwich the fiber base material 31. The laminate 33 is impregnated with the molten resin film 32 inside the fiber base material 31 to exhibit a predetermined strength, and is melted at a predetermined temperature during the fuel tank molding step described later to form a tank main body 1. Set appropriately so that it is welded. Further, the laminated body 33 is appropriately set so that each reinforcing band member is formed by being deformed at a predetermined temperature during the reinforcing band member forming step described later.

The design of the laminated body 33 can be changed as appropriate. For example, the fiber base material 31 made of a different material may be laminated for each base material. Further, each resin film 32 made of a different material may be laminated. Specifically, it is preferable that the outermost layer of the resin film 32 is a thermoplastic resin having good weldability to the tank body 1, and the inner layer is a thermosetting resin having good impregnation property with the fiber base material 31. .. The materials constituting the laminate 33 and the stacking order are appropriately set in consideration of the adhesiveness of the tank body 1 to the material and the strength characteristics (matching between the fiber base material 31 and the resin film 32) exhibited by the laminate 33. Is preferable. Further, the stacking order is not limited to the configuration in which the fiber base material 31 and the resin film 32 are alternately laminated, and the thermosetting resin film 32 having good impregnation property with respect to the fiber base material 31 and the tank body 1 Thermoplastic resin films 32 having good weldability may be laminated adjacent to each other.

The reinforcing band member forming step is a step of forming the lower reinforcing band member 21, the upper reinforcing band member 22, the lower angle reinforcing band member 23, and the upper angle reinforcing band member 24, respectively. As shown in FIG. 8, the reinforcing band member forming step is formed by using the reinforcing band forming die K composed of the lower die K1 and the upper die K2. The lower mold K1 and the upper mold K2 are each formed with a temperature control unit M capable of temperature control. In the reinforcing band member forming step, the laminate 33 is sandwiched between the lower die K1 and the upper die K2 and heated at a predetermined temperature to form, for example, the lower reinforcing band member 21 shown in FIG.

As shown in FIG. 10, the arranging step is a step of arranging the reinforcing band member group 2 on the fuel tank molding die J. The mold J for a fuel tank has a one mold J1 for molding the lower side and a other mold J2 for molding the upper side. Installation convex portions J1a and J1b are formed on one mold J1 and the other mold J2 of the fuel tank molding mold J, respectively. The installation convex portions J1a are formed on the bottom surfaces of the one-sided mold J1 and the other-sided mold J2 at predetermined intervals. The installation convex portion J1a is a portion where the lower reinforcing band member 21 or the upper reinforcing band member 22 is arranged, and is formed to have a substantially rectangular cross section. The installation convex portion J1a is also a portion for forming the concave portion 3 of the tank body 1.

The installation convex portion J1b is formed at the corners of the one-sided type J1 and the other-type J2, respectively. The installation convex portion J1b is a portion where the lower angle reinforcing band member 23 and the upper angle reinforcing band member 24 are arranged, and is formed to have a substantially rectangular cross section. The installation convex portion J1b is also a portion for forming the concave portions 5 and 6 of the tank body 1, respectively.

In the arranging step, each lower reinforcing band member 21 is arranged on each installation convex portion J1a of the one-sided mold J1, and each lower angle reinforcing band member 23 is arranged on each installation convex portion J1b. Further, in the arrangement step, each upper reinforcing band member 22 is arranged on each installation convex portion J1a of the other type J2, and each lower angle reinforcing band member 23 is arranged on each installation convex portion J1b. Since the one type J1 and the other type J2 are preheated to a predetermined temperature, when the reinforcing band member group 2 is arranged, the reinforcing band member group 2 and the one type J1 and the other type J2 are stuck to each other so as not to fall. become.

As shown in FIGS. 10 and 11, the fuel tank molding step is a step of blow molding the fuel tank T with the fuel tank molding die J. In the fuel tank forming step, a tubular or sheet-shaped parison P (FIG. 10) is discharged from the die D between the one-sided mold J1 and the other-type J2. The parison P is, for example, a thermoplastic resin composed of a plurality of layers including a barrier layer inside. The mold J for a fuel tank is preheated to a predetermined temperature so that the parison P is plastically deformed.

Then, as shown in FIG. 11, while molding the one-sided mold J1 and the other-sided mold J2, air is supplied to the inside for blow molding. The parison P is transferred to the molding surface of the fuel tank molding die J, and the parison P and the reinforcing band member group 2 (lower reinforcing band member 21, upper reinforcing band member 22, lower angle reinforcing band member 23, and upper angle reinforcing) are transferred. The band member 24) is welded and integrated. The parison P may be sucked by using the vacuuming means provided in the one-sided mold J1 and the other-sided mold J2, and the parison P may be transferred to the fuel tank molding mold J. After a predetermined time has passed, the mold is removed and the fuel tank T is taken out.

According to the fuel tank T and the method for manufacturing the fuel tank described above, the tank body 1 can be efficiently reinforced by the reinforcing band member group 2. More specifically, by installing the lower reinforcing band member 21 and the upper reinforcing band member 22 on the lower wall 11 and the upper wall 12, respectively, the lower wall 11 and the upper wall 12 on which a large positive pressure acts can be efficiently reinforced. Can be done. In particular, since the lower reinforcing band member 21 is continuously formed over the third side wall 15, the lower wall 11, and the fourth side wall 16, the reinforcing efficiency can be improved. Similarly, since the upper reinforcing band member 22 is continuously formed over the third side wall 15, the upper wall 12, and the fourth side wall 16, the reinforcing efficiency can be improved.

Further, by providing the lower angle reinforcing band member 23 and the upper angle reinforcing band member 24, the first side wall 13 and the second side wall 14 on which a large negative pressure acts can be reinforced. In particular, since the lower angle reinforcing band member 23 is continuously formed over the first side wall 13 and the lower wall 11, and is continuously formed over the second side wall 14 and the lower wall 11. , Reinforcement efficiency can be improved. Similarly, since the upper angle reinforcing band member 24 is continuously formed over the first side wall 13 and the upper wall 12, and is continuously formed over the second side wall 14 and the upper wall 12. Reinforcement efficiency can be increased.

Further, if the fiber reinforced resin is provided on the entire circumference of the fuel tank as in the conventional case, there is a problem that the material cost increases, but according to the present embodiment, the portion where the positive pressure or the negative pressure greatly acts is efficiently used. By reinforcing, the material cost can be reduced.

Further, since the recesses 3, 5 and 6 are formed on the outer surface of the tank body 1, the strength and rigidity of the tank body 1 can be increased. Further, the reinforcing band member group 2 (lower reinforcing band member 21, upper reinforcing band member, lower angle reinforcing band member 23, and upper angle reinforcing band member 24) is integrally formed in the recesses 3, 5 and 6, and is also recessed. Since it is composed of a bottom portion and a pair of side walls so as to follow the shapes of 3, 5 and 6, the reinforcement efficiency can be synergistically increased.

Further, since the lower reinforcing band member 21 and the upper reinforcing band member 22 are arranged at positions corresponding to the upper and lower sides, the strength of the fuel tank T can be increased in a well-balanced manner. Further, since the lower reinforcing band member 21 and the upper reinforcing band member 22 are arranged in parallel with each other at intervals, the strength of the fuel tank T can be increased in a well-balanced manner.

Further, both ends of the lower reinforcing band member 21 and the upper reinforcing band member 22 facing vertically, and the ends of the lower angle reinforcing band member 23 and the upper angle reinforcing band member 24 are the first side wall 13, the second side wall 14, The third side wall 15 and the fourth side wall 16 are arranged apart from each other at the central portion in the vertical direction. In other words, both ends of the lower reinforcing band member 21 and the upper reinforcing band member 22, and the ends of the lower angle reinforcing band member 23 and the upper angle reinforcing band member 24 are separated from each other with the parting line of the tank body 1 in between. It is located in. As a result, the strength of the fuel tank T can be increased in a well-balanced manner. Further, in the fuel tank molding step, the reinforcing band members facing each other can be molded without interfering with each other.

Further, in the arrangement step, the reinforcing band member group 2 is arranged on the installation convex portion J1a and the installation convex portion J1b provided on the fuel tank molding die J, so that the position shift of the reinforcing band member group 2 is prevented during molding. Can be done. Further, in the fuel tank molding step, since the reinforcing band member group 2 is welded to the parison P during blow molding, it can be easily integrally molded and the step between the tank body 1 and the reinforcing band member group 2 can be reduced. it can.

Further, the third side wall 15 and the fourth side wall 16 of the tank body 1 have an arc shape protruding sideways. Thereby, the strength against the external force acting from the outside of the third side wall 15 and the fourth side wall 16 can be increased. The first side wall 13 and the second side wall 14 may be formed so as to form an arc that projects laterally.

[Second Embodiment]
Next, as shown in FIG. 12, the fuel tank TA according to the second embodiment of the present invention will be described. The fuel tank TA is mainly different from the first embodiment in that it includes an opening 17, connection reinforcing band members 25, 25, and auxiliary reinforcing band members 26, 26. In the second embodiment, the parts different from the first embodiment will be mainly described.

The first side wall 13 is formed with three recesses 5, a lower angle reinforcing band member 23, and an upper angle reinforcing band member 24, respectively. Further, the second side wall 14 is formed with three recesses 6, a lower angle reinforcing band member 23, and an upper angle reinforcing band member 24, respectively.

A circular opening 17 is formed in the center of the upper wall 12 of the tank body 1. The opening 17 is a portion where a built-in component such as a pump module (not shown) is installed. The upper wall 12 is formed with recesses 7 and 7 connected to recesses 3 and 3 at both ends with the opening 17 interposed therebetween. The recesses 7 and 7 are extended in the front-rear direction, have a rectangular cross section, and are open upward. The recesses 7 and 7 are formed perpendicular to the recesses 3 and 3.

The connection reinforcing band member 25 is arranged inside the recess 7 and is integrally formed with the recess 7. The connection reinforcing band member 25 is composed of a bottom portion 25a and side walls 25b and 25b rising from both ends of the bottom portion 25a. The connection reinforcing band member 25 and the recess 7 are connected to the adjacent upper reinforcing band members 22, 22 and the recess 3, respectively. The connection reinforcing band members 25 and 25 are integrally formed by being welded to the upper reinforcing band members 22 and 22, respectively, by being overlapped during the fuel tank molding process. The connection reinforcing band members 25, 25 may be integrally formed with the upper reinforcing band members 22, 22 in the reinforcing band member forming step.

The auxiliary reinforcing band member 26 is arranged inside the recess 3 in the center and is integrally formed with the recess 3. The auxiliary reinforcing band member 26 on the right side is formed from the connecting reinforcing band member 25 on the right side to the central portion of the third side wall 15. The auxiliary reinforcing band member 26 on the left side is formed from the connecting reinforcing band member 25 on the left side to the central portion of the fourth side wall 16. The auxiliary reinforcing band member 26 is composed of a bottom portion 26a and side walls 26b and 26b rising from both ends of the bottom portion 26a. The auxiliary reinforcing band members 26 and 26 are integrally formed by being welded to the connecting reinforcing band members 25 and 25 by being overlapped during the fuel tank molding process. The auxiliary reinforcing band members 26, 26 may be integrally formed with the connecting reinforcing band members 25, 25 in the reinforcing band member forming step.

The fuel tank T according to the second embodiment described above can also achieve substantially the same effect as that of the first embodiment. Further, by providing the connection reinforcing band members 25, 25 connected to the upper reinforcing band members 22, 22, the strength in the front-rear direction can be increased. Further, by providing the connection reinforcing band members 25 and 25, it is possible to locally reinforce the portion to be strengthened, such as around the opening 17.

[Modification example]
FIG. 13 is a schematic cross-sectional view showing a modified example of the laminate forming step. FIG. 14 is a schematic cross-sectional view showing a modified example of the reinforcing band member. As shown in FIG. 13, in the reinforcing band member forming step, the laminate 33 is sandwiched between the lower mold K1 and the upper mold K2, and the auxiliary laminate 41 is provided in a part of the laminate 33. The composite laminated body 42 may be formed. The auxiliary laminated body 41 is provided by being laminated on a part of the laminated body 33 so as to increase the thickness. The auxiliary laminated body 41 is arranged so as to gradually become shorter as it is separated from the laminated body 33 (so that the length in the left-right direction in FIG. 13 becomes shorter).

As shown in FIG. 14, the reinforcing band member 2A is formed by the composite laminate 42 of FIG. The thickness of the outer corner of the reinforcing band member 2A is larger than that of other portions. Here, when increasing the strength of a part of the reinforcing band member, if the thickness of the entire laminated body is increased, the thickness of the portion that does not need to be reinforced also increases, which is uneconomical. However, by arranging the auxiliary laminate 41 at a predetermined position as in the modification, the thickness of the reinforcing band member 2A can be locally increased to efficiently increase the strength. That is, the reinforcing band member may be appropriately formed so that its thickness differs depending on the use of the fuel tank T. Further, by forming the auxiliary laminated body 41 so as to gradually become shorter as it is separated from the laminated body 33, it is possible to prevent the step on the outer surface of the corner portion from becoming large after molding.

Although the embodiments and modifications of the present invention have been described above, the design can be appropriately changed within a range not contrary to the gist of the present invention. In the present embodiment, the reinforcing band members are formed so as to be separated from each other at the central portion of the first side wall 13, the second side wall 14, the third side wall 15, and the fourth side wall 16, but they may overlap.

1 Tank body 2 Reinforcing band member group 3 Recessed 5 Recessed 6 Recessed 11 Lower wall 12 Upper wall 13 First side wall 14 Second side wall 15 Third side wall 16 Fourth side wall 17 Opening 21 Lower reinforcing band member (reinforcing band member)
22 Upper reinforcing band member (reinforcing band member)
23 Lower corner reinforcement band member (corner reinforcement band member)
24 Upper corner reinforcement band member (corner reinforcement band member)
26 Connection reinforcing band member 27 Auxiliary reinforcing band member T Fuel tank

Claims (9)

A fuel tank that has a lower wall, an upper wall, and a side wall, and is integrally provided with a plurality of reinforcing band members formed of a fiber reinforced resin on the outer surface of a tank body made of a thermoplastic resin including a barrier layer. hand,
The reinforcing strip member assumes a band shape, with being continuously welded across a pair of the side walls of the lower wall and the opposite, continuously been welded across a pair of the side walls of the upper wall and the opposite A fuel tank characterized by being present. The outer surface of the tank body has a concave portion having a concave cross section.
The fuel tank according to claim 1, wherein the reinforcing band member is formed in the recess and has a bottom portion along the recess and a pair of side walls rising from both ends of the bottom portion. The first or second aspect of the present invention, wherein the reinforcing band member of the upper wall and the reinforcing band member of the lower wall are arranged so that their ends face each other at the central portion of the side wall. Fuel tank. The fuel tank according to any one of claims 1 to 3, wherein a plurality of the reinforcing band members are arranged side by side at intervals. The fuel tank according to any one of claims 1 to 4, wherein the fuel tank has a connection reinforcing band member that connects adjacent reinforcing band members. The fuel tank according to any one of claims 1 to 5, wherein the side wall of the tank body has an arc shape that projects laterally. A corner reinforcing band member formed at a corner formed by the lower wall and the side wall adjacent to the lower wall, and at a corner formed by the upper wall and the side wall adjacent to the upper wall. The fuel tank according to any one of claims 1 to 6, wherein the fuel tank has. Before SL reinforcing strap member is formed by laminating a plurality of fiber base and a plurality of resin film, the outermost layer of the reinforcing strap member includes a feature that it is formed of a thermoplastic resin film The fuel tank according to any one of claims 1 to 7 . The fuel tank according to any one of claims 1 to 8, wherein the corner portion of the reinforcing band member is formed thicker than the other portion.

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