JP2012066739A - Sub-tank joint structure of vehicular fuel-tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sub-tank joint structure of a vehicular fuel-tank, which can restrain the deflection of a bottom wall of a tank body while reducing the number of components and its cost, and can prevent spot-welded parts from being detached due to fretful fuel.SOLUTION: Out of spot-welded points S1-S4 arranged in parallel in the direction A of shearing force applied to the spot-welded parts of a sub-tank 5 due to the movement of the fuel within the tank body 4, the spot-welded points S1, S4 arranged at least in both the ends thereof are offset in the direction B perpendicular to the direction A with respect to the spot-welded points S2, S3 which are intermediately arranged. On the bottom wall 3c of a lower tank 3, a main bead 3f is formed so that the adjacent two spot-welded points S2, S3 are almost symmetrically placed with respect to the same, and a sub bead 3g is formed so that the adjacent spot-welded points S1, S2 or S3, S4 are almost symmetrically placed with respect to the sub same, and further a sub bead 3g' is formed so that the adjacent spot-welded points S2, S3 are almost symmetrically placed with respect to the same.

Description

  The present invention relates to a subtank joint structure for a fuel tank for a vehicle, which includes a hollow tank body formed by coupling an upper tank and a lower tank and a subtank disposed in the tank body.

  In a fuel tank mounted on an automobile, the fuel in the tank body can be sucked up reliably even when the liquid level fluctuates due to the fuel in the tank body rippling during acceleration or deceleration of the vehicle. A sub tank is joined to the bottom wall portion by spot welding so that fuel is sucked from the sub tank.

  In this case, there is a concern that the bottom wall portion of the tank body may be bent due to vibration of the vehicle body during traveling, or that the spot welded portion of the sub tank may be peeled off due to fuel movement in the tank body.

  In order to prevent such problems of bending and peeling, for example, Patent Document 1 discloses a structure in which an elastic plate as another member is joined by spot welding between the bottom wall of the sub tank and the bottom wall of the tank body. Also disclosed is a structure in which an elastic piece as another member is bridged between the outer wall of the sub-tank and the bottom wall of the tank body and joined by spot welding. Further, in Patent Document 1, an H-shaped bead is formed on the bottom wall portion of the tank body, and an elastically deformable tongue piece is cut and formed on the bottom wall of the sub tank, and the bottom wall including the tongue piece is formed. Has been disclosed that is joined to the bottom wall of the tank body by spot welding.

Utility Model Registration Gazette No. 2504312

  By the way, when it is set as the structure which carries out spot welding of a sub tank and a tank main body via the elastic board and elastic piece of another member like the above-mentioned conventional structure, it will increase cost because the number of parts and the number of spot points increase. There's a problem.

  In addition, when the bead is formed on the bottom wall portion of the tank body and the tongue piece formed by cutting and raising the sub tank is spot-welded to the bottom wall portion as in the conventional case, the number of parts can be reduced, but the sub tank Special processing for cutting and raising the tongue piece is required, and there is a concern that fuel may leak from the notch, which may impair the function of the sub tank. In particular, in small cars where cost reduction is desired, it is difficult to adopt a structure that adds another member or special processing, and there is room to consider an optimal structure that can achieve cost reduction without impairing the function as a sub tank. .

  The present invention has been made in view of the above-described conventional situation, and while suppressing the number of parts and cost, it is possible to suppress the bending of the bottom wall portion of the tank body and to prevent the spot welded portion from being peeled off due to fuel movement. It is an object of the present invention to provide a subtank joining structure for a fuel tank for a vehicle.

  The present invention relates to a subtank joint of a fuel tank for a vehicle, comprising: a hollow tank body formed by coupling an upper tank and a lower tank; and a subtank disposed in the tank body and joined to a bottom wall portion of the lower tank. The sub-tank is joined by spot-welding the bottom wall of the sub-tank to the bottom wall of the lower tank, and a shearing force acting on the spot-welded spot spot-welded by the movement of fuel. The spot hitting points located at least at both ends of the plurality of spot hitting points arranged in parallel in the direction are offset in the direction perpendicular to the direction of the shearing force from the spot hitting point located in the middle, and on the bottom wall portion of the lower tank, The bead is formed so as to form a line-symmetrical substantially symmetrical axis between two adjacent spot hit points.

  According to the subtank joining structure according to the present invention, the spot hitting points located at both ends of the spot hitting points arranged in parallel in the direction in which the shearing force is generated by the fuel movement are perpendicular to the shearing direction from the spot hitting points located in the middle. Since the bead is formed on the bottom wall of the lower tank so as to form a line-symmetrical axis of symmetry between two adjacent spot hit points, the bottom of the tank body can be reduced while reducing the number of parts and cost. While suppressing the bending of a wall part, the peeling of the spot weld part by the movement of a fuel can be prevented.

  That is, the bending of the bottom wall portion of the tank main body caused by vibration during traveling can be suppressed by the bead formed on the bottom wall portion. Further, the shear force acting on the spot welded portion of the sub tank due to the fuel movement in the tank body and the sub tank can be distributed to the spot hitting points at the opposite ends and the intermediate spot hitting points. Concentration at the spot welded portion can be suppressed, and peeling of the spot welded portion can be prevented.

  Thus, in the present invention, it is possible to cope with the shearing force generated by both the vehicle body vibration and the fuel movement with a simple structure in which the arrangement positions of the beads and spot hitting points are specially set. A separate member can be dispensed with, and special processing for forming the tongue piece can be dispensed with, and the cost of a small vehicle can be reduced without impairing the function as a sub tank.

It is a top view of the state which removed the upper tank of the fuel tank by Example 1 of this invention. It is sectional drawing (II-II sectional view taken on the line of FIG. 1) of the said fuel tank. FIG. 3 is a cross-sectional view of the fuel tank (a cross-sectional view taken along line III-III in FIG. 1). It is a top view which shows the spot hitting point set to the said fuel tank.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 4 are views for explaining a sub-tank joint structure for a vehicle fuel tank according to a first embodiment of the present invention.

  In the figure, reference numeral 1 denotes a fuel tank mounted on an automobile. The fuel tank 1 includes a hollow tank body 4 in which an upper tank 2 and a lower tank 3 are joined oil-tightly by outer peripheral flange portions 2a and 3a by seam welding, and the tank body 4 is disposed in the tank body 4. And a sub tank 5 that opens upward.

  The tank body 4 is attached to a vehicle body (not shown) so that the longitudinal direction thereof is directed to the vehicle width direction. A fuel pump 7 that pressurizes the fuel in the sub tank 5 and supplies it to the engine is disposed in the sub tank 5 of the tank body 4. Reference numeral 9 denotes a fuel injection pipe connected to the upper tank 2.

  The fuel pump 7 is attached to the upper tank 2, and a fuel discharge pipe 7b is connected to an upper wall of a casing 7a in which a pump unit (not shown) is built, and a fuel suction pipe 7c is connected to a bottom wall. A filter 7d for filtering fuel is connected to the fuel suction pipe 7c.

  In the lower tank 3, a plurality of reinforcing beads 3b extending in the vehicle front-rear direction are formed at predetermined intervals in the vehicle width direction. Each reinforcing bead 3b is formed to bulge upward so as to form a convex shape, and extends from the bottom wall portion 3c of the lower tank 3 to the front and rear wall portions 3d and 3e.

  A tank seat surface 3 c ′ forming a flat surface is formed on the bottom wall portion 3 c of the lower tank 3. The tank seat surface 3c 'is formed at a position deviated to the left from the center in the vehicle width direction of the lower tank 3, and the sub tank 5 is placed on the tank seat surface 3c'.

  The sub-tank 5 has a substantially rectangular cup shape having the bottom wall 5a and a peripheral side wall 5b extending upwardly following the outer peripheral edge of the bottom wall 5a. The direction dimension is set to be large.

  At the front end and the rear end of the bottom wall 5a of the sub tank 5, bottom raised portions 5c, 5c are formed in a stepped shape, and a communication hole 5d is formed in the front bottom raised portion 5c.

  Spot hit points S <b> 1 to S <b> 4 are set on the bottom wall 5 a of the sub tank 5. The bottom wall 5a of the sub tank 5 is joined to the bottom wall portion 3c of the lower tank 3 by spot welding the spot hit points S1 to S4.

  The spot hit points S1 to S4 are along the direction A of the shearing force acting on each spot welded portion of the sub-tank 5 when the fuel in the tank body 4 and the sub-tank 5 moves in the front-rear direction during acceleration / deceleration of the vehicle. Are arranged in parallel and at a predetermined interval. That is, when the vehicle starts suddenly or suddenly brakes, the fuel in the tank body 4 and the sub tank 5 moves in the front-rear direction, and the fuel hits the sub tank 5 and the shearing force in the direction A acts on the spot weld.

  The spot hit points S1 to S4 are arranged on the left and right sides of a center line C in the front-rear direction passing through the center in the vehicle width direction of the bottom wall 5a of the sub tank 5, and are equally spaced in the direction A. Are arranged.

  Of the left and right spot hit points S1 to S4, spot hit points S1 and S4 located at both ends of the direction A are offset in a direction B perpendicular to the direction A from the spot hit points S2 and S3 located in the middle. Are arranged.

  Specifically, the spot hit points S1 and S4 located at both ends are offset inward in the vehicle width direction by D with respect to the straight line d passing through the spot hit points S2 and S3 located in the middle (see FIG. 4). This offset amount D is set to approximately 1/5 of the interval between the left and right spot hit points S2, S2 or S3, S3 adjacent in the vehicle width direction.

  The left and right spot hit points S1 to S4 are arranged so as to have line symmetry with the center line C as an axis of symmetry. Accordingly, the distances from the center line C to the left and right spot hit points S1 to S4 are equal.

  A bead 3h is formed on the bottom wall 3c of the lower tank 3 so as to bulge downward so as to form a concave groove. The bead 3h is composed of a main bead 3f extending in the direction A in which the shearing force is applied and a plurality of sub-beads 3g and 3g 'extending so as to expand outward in the vehicle width direction following the main bead 3f. In general, it is shaped like a king.

  Here, the main bead 3f is formed so as to form a substantially symmetrical axis between two spot hit points S2, S2 adjacent to each other in the vehicle width direction, and S3, S3. The sub-bead 3g 'is formed so as to form a substantially symmetrical axis of the spot hit points S2, S3 adjacent in the front-rear direction. Further, the sub-bead 3g is formed so as to form an approximately symmetrical axis of adjacent spot hit points S1, S2 or S3, S4, which are offset in the vehicle width direction. Since the spot hitting points S1 and S4 are offset, the sub-bead 3g extends from the front and rear end portions of the main bead 3f so as to be substantially radial.

  According to the present embodiment, the spot hit points S1 to S4 set on the bottom wall 5a of the sub tank 5 are arranged in parallel with a predetermined interval in the direction A of the shearing force acting on the spot welded portion, Among the right spot hit points S1 to S4, spot hit points S1 and S4 located at both ends of the direction A are offset in the direction B perpendicular to the direction A from the spot hit points S2 and S3 located in the middle, and the lower tank 3 Since the bead 3h is formed on the bottom wall portion 3c so as to form a substantially symmetrical axis of two adjacent spot hit points, the bottom wall portion 3c of the tank body 4 is bent while reducing the number of parts and the cost. While being able to suppress, it can prevent that a spot welding part peels by the shear force by the fuel movement in the tank main body 4. FIG.

  That is, the bending of the bottom wall portion 3c of the tank body 4 caused by vibration during traveling can be suppressed by the bead 3h formed on the bottom wall portion 3c.

  Further, the shearing force acting on the spot welded portion of the sub tank 5 by the movement of the fuel in the tank body 4 can be distributed to the spot spot S1, S4 at both ends and the intermediate spot spot S2, S3 arranged at the offset, It is possible to prevent the problem of peeling due to the shearing force that tends to concentrate on the spot welds at both ends.

  Thus, in this embodiment, the left and right spot hit points S1 and S4 arranged in parallel in the shearing force direction A are offset with respect to the intermediate spot hit points S2 and S3, and the left and right spot hit points S1. A simple structure in which the bead 3h is formed so as to be approximately the axis of symmetry of S4, and the arrangement positions of the main bead 3f, the sub-beads 3g and 3g 'and the minimum required spot hit points S1 to S4 are set. It can cope with the shearing force generated from both vehicle vibration and fuel movement, can eliminate the need for separate members such as conventional elastic plates, and can eliminate the need for special processing to form tongue pieces, It is possible to meet the demand for cost reduction of small cars without impairing the functions.

  Further, since the sub beads 3g and 3g 'extending outward in the vehicle width direction are formed subsequent to the main bead 3f, it is possible to obtain an optimum shape for suppressing the deflection of the tank body 4, and the external force from which direction. Also, it can be distributed to at least two spot hit points.

  In the above-described embodiment, the bead is formed so as to form a substantially symmetrical axis of all adjacent spot hit points. However, in the present invention, the bead is formed so as to form a substantially symmetrical axis of some adjacent spot hit points. It ’s fine.

DESCRIPTION OF SYMBOLS 1 Fuel tank 2 Upper tank 3 Lower tank 3c Bottom wall part 3h Bead 4 Tank main body 5 Sub tank 5a Bottom wall A Shear force direction B Orthogonal direction C Symmetry axis S1-S4 Spot hit

Claims (1)

A subtank joining structure for a fuel tank for a vehicle, comprising: a hollow tank body formed by coupling an upper tank and a lower tank; and a subtank disposed in the tank body and joined to a bottom wall portion of the lower tank. ,
The sub tank is joined by spot welding the bottom wall of the sub tank to the bottom wall of the lower tank,
By moving the fuel, the spot hitting points located at least at both ends of the plurality of spot hitting points arranged in parallel in the direction of the shearing force acting on the spot welded spot hitting spot are moved from the spot hitting point located in the middle. Offset in the direction perpendicular to the direction,
A sub-tank joining structure for a fuel tank for a vehicle, wherein a bead is formed on a bottom wall portion of the lower tank so as to form a line-symmetrical substantially symmetrical axis between two adjacent spot hit points.

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