JP2011225022A - Fuel tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel tank, in which reduction in weight is achieved by suppressing stress concentration and effectively increasing the natural frequency of the fuel tank as a whole.SOLUTION: A curved surface is composed of a complex curved surface having at least eight curved surfaces A, B, C, D, T, which include a first curved surface 7b1 having a curvature formed in a horizontal cross section passing on the center portion P of the end plate 7, a second curved surface 7b2 having a curvature formed in a vertical cross section perpendicular to the horizontal cross section and passing on the center portion P, and a third curved surface 7b3 having a curvature formed in a cross section perpendicular to each triangular region T including the center portion P and each corner portion R of four corners and extending in a direction along a diagonal line S. Furthermore, extended lines of both-side edges T1, T2 that hold the center portion P of the triangular region T are set to extend toward intersections R1, R2, which are located inside the range defined by R0 and R0' wherein the curvature of the corner portion R of a drum 6 ends, and cross.

Description

The present invention relates to a fuel tank capable of improving durability and realizing weight reduction.

Technological development is required for fuel tanks mounted on vehicles from the viewpoint of improving vibration durability and promoting weight reduction.
The applicant previously filed a patent application regarding an invention relating to a fuel tank that is advantageous in improving vibration durability, as described in Patent Document 1 from the above viewpoint. The fuel tank in the invention according to this application is provided with an X-shaped main bead serving as a skeleton in a diagonal direction from the upper corner portion to the lower corner portion on the separator disposed on the inner surface of the cylindrical drum. The main bead has a configuration in which both ends of the main bead are smoothly connected to the flange of the separator by an arcuate curved surface. Thereby, the vibration durability is improved.

However, in the fuel tank of the above-mentioned Patent Document 1, the fuel tank is configured using an end plate that is merely formed with a bulge portion that bulges with a curvature on the outside. . For this reason, there is a limit to improving the vibration durability and reducing the weight of the fuel tank.
In addition to the above-mentioned Patent Document 1, Patent Document 2 and Patent Document 3 are known as techniques related to the end plate of the fuel tank. The X-shaped main bead is formed on the end plate of the fuel tank described in Patent Document 2, and the X-shaped main bead is formed not only on the end plate but also on the separator disposed in the middle in the fuel tank described in Patent Document 3. It has the composition which is.

Patent Document 1 Japanese Patent Application Laid-Open No. 2006-62491 Patent Document 2 Japanese Patent Application Laid-Open No. 2002-127765 Patent Document 3 Japanese Patent Application Laid-Open No. 2008-248696

However, the prior art described in Patent Document 2 and Patent Document 3 described above has a configuration in which an X-shaped main bead is provided on the end plate. Therefore, when the fuel tank is restrained (secured) to the side frame (chassis frame) via the belt, the end face of the part where the main bead intersects in the X shape as a result of the securing force extending from the belt to the end plate or separator. Stress tends to concentrate on
The present invention has been devised to solve such a problem, and it is possible to reduce the weight by suppressing the stress concentration and effectively increasing the natural frequency of the end plate, the separator, and the fuel tank as a whole. It aims at providing the fuel tank which can plan.

(1) For this reason, the following measures are taken in the present invention. That is, according to the first aspect of the present invention, an end plate having a curved surface bulging outward is joined to a drum opening end having a substantially square cross section to close the drum opening end, and the drum opening end corresponds to the bracket. In a fuel tank in which a separator is accommodated in a drum, the curved surface is orthogonal to the horizontal cross section passing through the central portion and a first curved surface in which a curvature is formed in a horizontal cross section passing through the central portion of the end plate. At least 8 of a second curved surface in which a curvature is formed in a vertical cross section and a third curved surface in which a curvature is formed in a cross section orthogonal to each triangular region including the corner portions of the central portion and the four corners and extending in a diagonal direction. An inward in which an extended line of both side edges sandwiching the central portion of the triangular region is sandwiched between R stops at the corner portion of the drum. It is set so as towards extending a fuel tank characterized by.

According to the present invention, the third curved surface is formed in the triangular region of the end plate having the composite curved surface, and the extension lines on both side edges of the triangular region extend inwardly between the R stops at the corners of the drum. Is set to For this reason, the compound curved surface of the end plate approaches an in-plane stress state, and a binding force flows to the central portion serving as a neutral axis, and the triangular region in the diagonal direction functions as a skeleton. In addition, even if a lashing force from the belt acts on the skeleton in a diagonal direction, the concentration of stress near the corner portion of the end plate is suppressed, and the lashing force can be smoothly distributed. As a result, it is possible to reduce the weight of the fuel tank by manufacturing a fuel tank in which the deformation of the end plate is suppressed using a thin material.
Further, since the rigidity of the entire end plate is enhanced, the natural vibration value of the fuel tank can be increased, and a fuel tank having excellent vibration durability can be realized.

(2) In the invention according to claim 2, an end plate is joined to a drum opening end having a substantially square cross section to close the drum opening end, and a separator is provided in the drum corresponding to a bracket. In the fuel tank stored and arranged, the separator has a curved surface that bulges outward, and the curved surface passes through the central portion and a first curved surface in which a curvature is formed in a horizontal section passing through the central portion of the separator. Then, the curvature is formed in the second curved surface in which the curvature is formed in the vertical section orthogonal to the horizontal section and the section orthogonal to each triangular region including the central portion and each corner portion of the four corners and extending in the diagonal direction. It is composed of a compound curved surface having at least eight curved surfaces with a third curved surface, and an extension line on both side edges sandwiching the central portion of the triangular area is an R stop at the corner portion of the drum. It is a fuel tank, characterized in that is configured to extend inward sandwiched Ri.

According to the present invention, as in the first aspect of the invention, the third curved surface is formed in the triangular region of the separator having a composite curved surface, and the extension lines on both side edges of the triangular region are the R stop at the corner portion of the drum. It is set so as to extend toward the inward direction. For this reason, when the separator approaches the in-plane stress state, a force flows to the central portion of the separator that becomes a neutral axis. As a result, the triangular region in the diagonal direction exhibits a function as a skeleton, and stress is concentrated near the corner portion of the separator even if an external force in the diagonal direction, in other words, a binding force from the belt acts on the skeleton. The restraining force can be smoothly dispersed while restrained. As a result, it is possible to reduce the weight of the fuel tank by manufacturing a fuel tank that can suppress deformation of the separator using a thin plate material.
Further, since the rigidity of the separator itself is increased, the natural vibration value of the fuel tank can be increased, and a fuel tank having excellent vibration durability can be realized.

(3) The invention according to claim 3 is the fuel tank according to claim 1, wherein the separator is constituted by the separator according to claim 2.
According to the present invention, stress concentration does not occur in the corner portion of the end plate and the corner portion of the separator even when a binding force by the belt is applied. For this reason, it is possible to suppress the deformation of the end plate and the separator. As a result, a fuel tank with reduced weight can be obtained, and a fuel tank that is excellent in durability and advantageous in vibration durability can be realized.

  According to the present invention, a fuel tank using an end plate or a separator that suppresses the occurrence of stress concentration increases the natural vibration value, has excellent vibration durability, and uses a thin material to reduce weight. The fuel tank which can do is realizable.

1 is an external perspective view of a fuel tank according to an embodiment of the present invention, partially broken away and seen through. Similarly, it is the external appearance perspective view which displayed the end plate shown in FIG. 1 with the diagram by the finite element method. Similarly, it relates to the three views of the end plate shown in FIG. 2, (a) is a front view, (b) is a cross-sectional view taken along line XX of (a), and (c) is YY of (a). The arrow sectional drawing in a line, (d) is sectional drawing in the dd line | wire of (a). Similarly, it is related with the three-plane figure of the separator shown in FIG. 1, (a) is a front view, (b) is an arrow sectional view in the XX line of (a), (c) is the YY line of (a). The arrow sectional drawing in (d) is sectional drawing in the dd line | wire of (a). Similarly, it is an arrow sectional view in the YY line of FIG. 1 for explaining a state where the fuel tank is attached to the chassis frame via a bracket.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. As shown in FIGS. 1 and 5, the fuel tank 1 according to the present embodiment is manufactured by incorporating elements obtained by processing a metal material such as a steel plate, a stainless steel plate, and an aluminum alloy plate by joining such as welding. Is done. The fuel tank 1 is set (placed) on a bracket 3 bent in a substantially L shape on the chassis frame 2, and is positioned and secured to the bracket 3 with a belt 4 in the form of a belt that is routed around the fuel tank 1. By doing so, it can be mounted on a vehicle. The belt 4 is routed around the fuel tank 1 so as to correspond to the position where the separator 8 is disposed. Reference numeral 5 in FIG. 5 denotes a rubber as a friction contact member provided between the bracket 3 and the belt 4 and the fuel tank 1.

The configuration of the fuel tank 1 will be described more specifically. The fuel tank 1 mainly includes a drum 6 having a substantially rectangular cross section, two substantially square end plates 7 joined to the front and rear opening ends thereof to block the drum 6 from the outside, and the drum 6 accommodated in the drum 6 and joined. And a separator 8 for reinforcing the drum 6. In this embodiment, the case where three sheets are used has been described as an example, but the number of sheets used is not limited to this.

As shown in FIGS. 1 to 3, the end plate 7 has a curved surface 7 b that bulges outward from the fuel tank 1 and a flange 7 a that is bent in a direction in which the curved surface 7 b bulges so as to surround its periphery. Is formed. The curved surface 7b is a first curved surface 7b1 (see FIG. 3 (b)) formed with a predetermined curvature in a horizontal section (cross section XX shown in FIG. 3) passing through the central portion (center point) P of the end plate 7. Similarly, a second curved surface 7b2 (see FIG. 3 (c)) formed with a predetermined curvature in a vertical section (cross section YY in FIG. 4) passing through the central portion P and orthogonal to the horizontal section, Four third curved surfaces 7b3 (where the curvature is formed in a cross section perpendicular to each triangular region (portion indicated by hatching in FIG. 3A) including the portion P and the corner portions R of the four corners and extending in the diagonal line S direction) 3 (d)) and a complex curved surface having at least eight curved surfaces. The triangular area T will be described in detail later.

As shown by hatching in FIG. 3A, the end plate 7 is formed with four areas approximate to a triangle, that is, a triangular region T so as to sandwich the corner portion R from the center portion P. The third curved surface 7b3 in the triangular region T is formed from the central portion P to the corner portion R with substantially the same curvature.
The drum 6 is formed with a predetermined curvature in the range of R0 and R0 '. Note that R0 and R0 'are called R stops and define the range of the corner portion. There are two side edges (curved edges) T1 and T2 on both sides of the center portion P of the triangular region T, and an extension line of these side edges T1 and T2 defines an R stop R0 that defines the range of the corner portion of the drum 6 , R 0 ′, and is set so as to extend toward and intersect the intersections R 1 and R 2 located inward.

In this way, the surfaces B and D that form the first curved surface 8b1, the surfaces A and C that form the second curved surface 8b2, and the four triangular regions T that form the third curved surface 8b3 are smooth while gradually changing their curvature. To be continuous. Thus, one composite curved surface that bulges outward as a whole is formed on the end plate 7. Then, an external force (fixed force) acts in the diagonal S direction of the triangular region T where the extension lines of the side edges T1 and T2 of the triangular region T intersect the intersections R1 and R2 positioned inwardly between the R stops R0 and R0 ′. The skeletal function for binding force) can be demonstrated.

Next, the separator 8 will be described. As shown in FIGS. 4A to 4D, the separator 8 has substantially the same form as the end plate 7 described above. It should be noted that substantially the same parts as those in FIG. That is, as shown in FIG. 4, the separator 8 is formed with a bulging curved surface 8b and a flange 8a that surrounds the periphery of the curved surface 8b and is bent to the same side as the bulging direction of the curved surface 8b. Yes. The curved surface 8b is a first curved surface 8b1 (see FIG. 4 (b)) formed with a predetermined curvature in a horizontal section (cross section XX shown in FIG. 4) passing through the central portion (center point) P of the separator 8. Similarly, a second music piece 8b2 (see FIG. 4C) formed with a predetermined curvature in a vertical section YY passing through the center section P and orthogonal to the horizontal section XX, the center section P and the four corners Four third curved surfaces 8b3 (FIG. 4 (d)) in which a curvature is formed in a cross section orthogonal to each triangular region (the portion shown by hatching in FIG. 4 (a)) extending in the diagonal S direction including each corner portion R of FIG. And a compound curved surface having at least eight curved surfaces.

As shown by hatching in FIG. 4A, the separator 8 is formed with four areas that approximate a triangle so as to sandwich the corner portion R from the center portion P, that is, a triangular region T. The third curved surface 8b3 in the triangular region T is formed from the central portion P to the corner portion R with substantially the same curvature.
The drum 6 is formed with a predetermined curvature in the range of R0 and R0 '. Note that R0 and R0 'are called R stops and define the range of the corner portion. There are two side edges (curved edges) T1 and T2 on both sides of the center portion P of the triangular region T, and an extension line of these side edges T1 and T2 defines an R stop R0 that defines the range of the corner portion of the drum 6 , R0 'and set so as to extend toward the intersections R1 and R2 located inside.

Thus, in the same manner as the end plate 7, the separator 8 has the surfaces B and D that form the first curved surface 7b1, the surfaces A and C that form the second curved surface 7b2, and the four triangular regions T that form the third curved surface 7b3. Are connected so as to form a smooth continuous surface while gradually changing the curvature. The separator 8 is formed with one composite curved surface that bulges outward as a whole. As a result, the triangular region T in which the extension lines of the side edges T1 and T2 of the triangular region T intersect with the R stops R1 and R2 can exhibit a skeletal function with respect to an external force (clamping force) acting in the diagonal S direction. It has become.

The fuel tank 1 is placed on a bracket 3 fixed to the chassis frame 2, and is secured to the chassis frame 2 via the bracket 4. At this time, consideration is given so that the position of the separator 8 coincides with a position substantially corresponding to the bracket 3 so that the binding force of the belt 4 is received by the separator 8 via the drum 6.

According to this embodiment, the extension lines of the side edges T1 and T2 of the triangular region T of the end plate 7 and the separator 8 intersect the intersections R1 and R2 located inside the R stops R0 and R0 ′ of the drum 6. Is set. For this reason, when the end plate or the separator approaches the in-plane stress state, a force flows through the central portion P serving as a neutral axis, so that the triangular region T has a skeleton, that is, an external force (binding force) acting in the diagonal S direction. It has a structure that raises the rigidity by causing the function as a brace. Therefore, even if the binding force F by the belt 4 acts along the triangular region T via the fuel tank 1 as shown in FIG. 5, stress concentration does not occur in the end plate 7 and the separator 8. As a result, the natural vibration value of the fuel tank 1 itself can be increased and the strength against the vibration can be increased. In other words, the separator 8 is peeled off from the drum 6 due to the vibration of the vehicle body that occurs when the vehicle travels or the vibration of the fuel inside the fuel tank. As a result, it is possible to avoid a decrease in the securing force F against the fuel tank 1 and to improve the durability of the fuel tank 1.

Moreover, since the curved surface bulged to the end plate 7 and the separator 8 can be made to be a composite curved surface, the rigidity can be increased. Therefore, the end plate 7 and the separator 8 can be manufactured using a thin material, and the fuel tank There is an advantage that the weight can be reduced.
As mentioned above, although one embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention, the present invention. It is included in the range.
For example, in the above-described embodiment, the case where the fuel tank 1 is configured using the end plate 7 and the separator 8 formed in a compound curved surface having the triangular region T has been described. Needless to say, the present invention can also be applied to the case where the fuel tank 1 is configured in a form having a curved surface having a compound curved surface in which only one of the triangular regions T is provided.

In the above embodiment, the end plate 7 and the separator 8 have a substantially quadrangular shape. Therefore, the case where the number of curved surfaces in the composite curved surface is eight is described as an example. Of course, the shape is not limited to this, and the number of curved surfaces forming the complex curved surface may be eight or more. For example, the end plate 7 or the separator 8 having a polygonal shape such as a pentagon or a hexagon may be used. In addition, even when the end plate 7 or the separator 8 has a substantially square shape as in the present embodiment, the number of curved surfaces forming the complex curved surface may be formed by eight or more curved surfaces.

The present invention can be used for a fuel tank that can improve durability and achieve weight reduction.

DESCRIPTION OF SYMBOLS 1 Fuel tank 2 Chassis frame 3 Bracket 4 Belt 5 Rubber 6 Drum 7 End plate 7a Flange 7b Swelling curved surface 7b1 First curved surface 7b2 Second curved surface 7b3 Third curved surface 8 Separator 8a Flange 8b Swelling curved surface 8b1 First curved surface 8b2 Second curved surface 8b3 Third curved surface 8c Through holes A, B, C, D Curved surface P Center portion R Corner portion R0, R0'R Stop R1, R2 Intersection S Diagonal line T Triangular region T1, T2 Side edge

Claims (3)

  A fuel tank in which an end plate having a curved surface bulging outward is joined to a drum opening end having a substantially square cross section to close the drum opening end, and a separator is accommodated in the drum corresponding to a bracket. The first curved surface in which a curvature is formed in a horizontal cross section passing through the central portion of the end plate, and a first curved surface in which a curvature is formed through the central portion and perpendicular to the horizontal cross section. 2 curved surfaces and a composite curved surface having at least eight curved surfaces of a third curved surface in which a curvature is formed in a cross section orthogonal to each triangular region including the central portion and the four corner portions extending in a diagonal direction, Further, an extension line of both side edges sandwiching the central portion of the triangular area is set so as to extend inwardly between the R stops at the corner portion of the drum. Fuel tank, wherein the Rukoto.   In a fuel tank in which an end plate is joined to a drum opening end having a substantially square cross section to close the drum opening end, and the separator is accommodated in the drum corresponding to a bracket, the separator expands outward. While the curved surface has a curved surface, the curved surface has a curvature in a first curved surface in which a curvature is formed in a horizontal section passing through the central portion of the separator, and in a vertical section that passes through the central portion and is orthogonal to the horizontal cross section. A composite curved surface having at least eight curved surfaces: a second curved surface to be formed and a third curved surface in which a curvature is formed in a cross section orthogonal to each triangular region including the central portion and the four corner portions extending in a diagonal direction. Further, an extension line of both side edges sandwiching the central portion of the triangular region extends inwardly sandwiched between R stops at the corner portion of the drum. A fuel tank, characterized in that it is set to.   The fuel tank according to claim 1, wherein the separator comprises the separator according to claim 2.

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