JP2018167721A - Fuel tank for automobile - Google Patents

Abstract

To provide fuel tank for an automobile, which is formed of a thermoplastic synthetic resin and in which tank projections are formed on a bottom wall of the fuel tank for the automobile to reduce the occurrence of oscillating sound caused by the oscillation of fuel.SOLUTION: A fuel tank 1 for an automobile has a tank outer wall 10 formed of a thermoplastic synthetic resin and is provided with a plurality of tank projections 20 that are formed integrally therewith to project from the tank bottom wall 12 of the tank outer wall 10 inward of the fuel tank 1. The plurality of tank projections 20 are formed in rows arrayed in a direction almost perpendicular to a vehicle travel direction with spaces provided between the tank projections 20. The rows of the tank projections 20 are formed in the plurality of rows in the same direction with the travel direction, and the tank projections 20 in the rear row with respect to the vehicle travel direction are formed to face the space portions between the tank projections 20 in the front row.SELECTED DRAWING: Figure 2

Description

The present invention relates to an automobile fuel tank in which a tank protrusion is provided on the bottom wall of an outer wall of an automobile fuel tank having an outer wall formed of a thermoplastic synthetic resin to control the wave of fuel.

Conventionally, the structure of fuel tanks for automobiles and the like has been made of metal. However, in recent years, the weight of the vehicle is reduced, rust is not generated, and it is easy to form into a desired shape having a recess or the like. For example, those made of thermoplastic synthetic resin have been used.
In the production of an automotive fuel tank made of a thermoplastic synthetic resin, a blow molding method has been often used because of the ease of molding a hollow body. In the blow molding method, a parison of a molten thermoplastic synthetic resin member is formed into a cylindrical shape and extruded from above, and the parison is sandwiched between molds and air is blown into the parison to manufacture an automobile fuel tank.

In the fuel tank 101, the fuel inside the fuel tank oscillates at the time of traveling, decelerating, or stopping, and a fuel oscillating noise is generated.
In this case, as shown in FIG. 7, an upper baffle 113 is formed from the upper wall 111 of the outer wall 110 of the fuel tank 101 to the inside of the fuel tank 101, and from the bottom wall 112 of the outer wall 110 to the inside of the fuel tank 101. A bottom baffle 114 is formed (see, for example, Patent Document 1).

In this case, when the fuel inside the fuel tank 1 decreases, the upper baffle 113 does not hit the upper baffle 113, and the effect of reducing the fluctuation of the fuel is reduced. Further, if the bottom baffle 114 attempts to reduce the fluctuation of the fuel, the bottom baffle 114 becomes larger or increases in number, so that the capacity of the fuel tank 1 is greatly reduced and the inside of the fuel tank 1 is increased. There is a risk of clogging the fuel flow.

Further, as shown in FIG. 8, a baffle plate 212 fixed horizontally is provided below the fuel tank 201, and the inside of the fuel tank 201 is divided into an upper fuel chamber 214 and a lower fuel chamber 213 by the baffle plate 212, The upper fuel chamber 214 and the lower fuel chamber 213 are communicated with each other through a plurality of communication holes 215 provided in the baffle plate 212. Then, when fuel is injected into the fuel tank 201 that has run out of fuel, the fuel is gently allowed to flow through the communication hole 215 so that the fuel at the bottom of the fuel tank 201 is not agitated rapidly. There are some (see, for example, Patent Document 2).

However, in this case, if the baffle plate 212 is extended to the bottom surface of the tank outer wall 211 in order to prevent agitation of fuel at the bottom of the fuel tank 201, the baffle plate 212 and the tank outer wall 211 may come into contact with each other. .

JP 2012-224113 A JP-A-10-89180

  Therefore, the present invention provides an automobile fuel tank in which a tank protrusion is formed on the bottom wall of an automobile fuel tank having an outer wall formed of a thermoplastic synthetic resin to prevent the generation of an oscillating sound due to the oscillation of the fuel. The task is to do.

The present invention of claim 1 for solving the above-mentioned problem is a fuel tank for automobiles having a tank outer wall formed of a thermoplastic synthetic resin.
Providing a plurality of tank protrusions integrally formed protruding from the tank bottom wall of the tank outer wall to the inside of the fuel tank,
The plurality of tank protrusions are formed in a line that is arranged in a direction substantially perpendicular to the traveling direction of the vehicle with a gap between the tank protrusions, and the tank protrusions are aligned with the traveling direction of the vehicle. It is formed as a plurality of rows in the same direction as the direction, and the tank projections in the rear row with respect to the traveling direction of the vehicle are formed so as to face the gap portions between the tank projections in the front row and the tank projections, respectively. It is the fuel tank for vehicles characterized.

According to the first aspect of the present invention, in the automobile fuel tank having a tank outer wall formed of a thermoplastic synthetic resin, a plurality of tanks integrally formed so as to protrude from the tank bottom wall of the tank outer wall to the inside of the fuel tank. Protrusions are provided. Therefore, a plurality of tank protrusions can be formed at the same time as the outer wall of the tank is formed, and the tank protrusion provided on the tank bottom wall reduces the fluctuation of the fuel even if the fuel inside the fuel tank decreases. Therefore, the rocking noise generated when the fuel is rocked can be reduced.

The plurality of tank protrusions are formed in a line arranged in a direction substantially perpendicular to the traveling direction of the vehicle with a gap provided between the tank protrusions. For this reason, fuel can flow between the tank protrusion and the tank protrusion, and the fuel hits the tank protrusion, thereby reducing the swing speed and reducing the swing noise. The oscillation of the fuel can be suppressed over a wide range in the width direction with respect to the traveling direction of the vehicle on the tank bottom wall.

The row of tank projections is formed as a plurality of rows in the same direction as the vehicle traveling direction, and the tank projections in the rear row are opposed to the gaps between the tank projections in the front row and the tank projection, respectively. It is formed to do. For this reason, the fuel flowing from the gap between the tank protrusions in the front row strikes the tank protrusions in the rear row while generating turbulence, and consumes kinetic energy at the time of fuel oscillation, effectively. The rocking speed of the fuel can be reduced and the rocking noise can be reduced.

The present invention of claim 2 is an automobile fuel tank in which the tank projection is formed in a substantially quadrangular prism shape.

In the second aspect of the present invention, since the tank protrusion is formed in a substantially quadrangular prism shape, the front surface and the rear surface, which are the surfaces of the tank protrusion in the opposite direction to the traveling method of the vehicle, are planar, and are opposite to the traveling direction of the vehicle. The fuel hits the fuel flow in both directions, making it easy to generate turbulent flow and consuming kinetic energy at the time of fuel swinging, effectively speeding the fuel swing Can be reduced, and the rocking noise can be reduced.

According to the third aspect of the present invention, two to three rows of tank protrusions are formed on the front side with respect to the traveling direction of the vehicle on the tank bottom wall, and two rows on the rear side with respect to the traveling direction of the vehicle on the tank bottom wall. It is a fuel tank for automobiles formed in three rows.

According to the third aspect of the present invention, two to three rows of tank protrusions are formed on the front side with respect to the traveling direction of the vehicle on the tank bottom wall, and two rows on the rear side with respect to the traveling direction of the vehicle on the tank bottom wall. Three rows are formed. For this reason, when the fuel is swung back and forth in the traveling direction of the vehicle, two or three rows of tank protrusions formed on the front side and two or three rows of tank protrusions formed on the rear side are swung in both directions. In contrast, it is possible to effectively reduce the rocking speed of the fuel and reduce the rocking noise.

According to the fourth aspect of the present invention, the tank projection has a height of 1.5 to 2 cm, a width perpendicular to the traveling direction of the vehicle of 3 to 5 cm, and a depth of 2 to 3 cm in the same direction as the traveling direction of the vehicle. It is a fuel tank for automobiles.

In the present invention of claim 4, the tank protrusion has a height of 1.5 to 2 cm, a width in a direction perpendicular to the traveling direction of the vehicle of 3 to 5 cm, and a depth of 2 to 3 cm in the same direction as the traveling direction of the vehicle. It is formed to be. For this reason, the rocking speed of the fuel can be effectively reduced and the rocking noise can be reduced without increasing the size of the tank protrusion and without greatly reducing the capacity of the fuel tank.

When the height of the tank protrusion is less than 1.5 cm, sufficient vertical turbulence does not occur when the fuel swings. When the height of the tank protrusion exceeds 2 cm, the capacity of the fuel tank It is useless because it decreases. When the width of the tank protrusion is less than 3 cm and when the depth of the tank protrusion is less than 2 cm, sufficient lateral turbulence does not occur when the fuel swings, and the width of the tank protrusion exceeds 5 cm. When the depth of the tank protrusion exceeds 3 cm, the capacity of the fuel tank is reduced, which is useless.

According to the fifth aspect of the present invention, the distance between the tank protrusions in the row of tank protrusions is 1 to 2 cm, and the distance between the row of tank protrusions and the row of tank protrusions is 1 to 2 cm. Fuel tank.

According to the present invention of claim 5, the interval between the tank protrusions of the tank protrusion rows is 1 to 2 cm, and the interval between the tank protrusion rows and the tank protrusion rows is 1 to 2 cm. Is formed. For this reason, when the fuel swings between the tank protrusions, a turbulent flow is generated on the rear surface of the tank protrusions, thereby reliably reducing the swing speed and reducing the swing noise.

When the distance between the tank protrusions in the row of tank protrusions is less than 1 cm, less fuel flows between the tank protrusions when the fuel swings, and less kinetic energy is consumed when the fuel swings. Therefore, when the distance between the tank protrusions exceeds 2 cm, turbulent flow is less generated with respect to the fuel flowing between the tank protrusions when swinging, and the amount of kinetic energy consumed when the fuel swings Less.

According to a sixth aspect of the present invention, there is provided an automobile fuel tank in which the front surface of the tank protrusion in the vehicle traveling direction is inclined from 0 to 15 degrees rearward from a right angle with respect to the tank bottom wall.

According to the sixth aspect of the present invention, the front surface of the tank protrusion in the vehicle traveling direction is formed so as to be inclined backward by 0 to 15 degrees from a right angle with respect to the tank bottom wall. For this reason, when the fuel swings, the fuel flows along the front surface of the tank protrusion in the vehicle traveling direction, and turbulent flow is generated on the upper surface of the tank protrusion. Energy can be consumed, the rocking speed can be reliably reduced, and rocking noise can be reduced.

When the front surface of the tank protrusion in the traveling direction of the vehicle is tilted rearward at a right angle of more than 15 degrees with respect to the tank bottom wall, turbulence occurs when the fuel flows beyond the upper surface of the protrusion. It becomes difficult.

The plurality of tank protrusions provide a gap between the tank protrusions so that fuel can flow between the tank protrusions and the tank protrusions, and the fuel hits the tank protrusions to reduce the swing speed. , Rocking noise can be reduced.
The rear row tank protrusions are formed so as to face the gaps between the front row tank protrusions and the tank protrusion, respectively. By hitting the tank protrusion, the kinetic energy at the time of fuel swinging can be consumed, and the rocking noise can be reduced.

It is the perspective view seen from diagonally upward of the fuel tank which is embodiment of this invention. It is sectional drawing of the fuel tank which is embodiment of this invention. It is the perspective view seen from the diagonal upper side of the bottom wall of the fuel tank which is embodiment of this invention. It is an expansion perspective view of the part of the tank projection of the bottom wall of the fuel tank which is an embodiment of the invention. It is a schematic diagram of the cross section which shows the flow of the fuel with respect to the tank protrusion of the bottom wall of the fuel tank which is embodiment of this invention. It is a schematic diagram of the plane which shows the flow of the fuel with respect to the tank protrusion of the bottom wall of the fuel tank which is embodiment of this invention. It is sectional drawing of the conventional fuel tank. It is sectional drawing of the other conventional fuel tank.

A tank projection 20 formed on a tank outer wall 10 of an automotive fuel tank 1 according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a fuel tank 1 according to an embodiment of the present invention. The tank outer wall 10 of the thermoplastic synthetic resin fuel tank 1 may have a single-layer or multi-layer structure. The fuel tank 1 is formed by blow molding, and the tank upper wall 11 and the tank bottom wall 12 of the tank outer wall 10 are integrally formed.

As shown in FIG. 1, the fuel tank 1 manufactured according to the embodiment of the present invention has a pump unit mounting hole 4 formed on the upper surface so that a fuel pump (not shown) and the like can be taken in and out of the fuel tank 1. ing. A fuel injection hole 5 for injecting fuel from an inlet pipe (not shown) is formed on the side surface or the upper surface of the fuel tank 1.

Further, for example, an outer peripheral rib 2 is formed around the entire circumference of the fuel tank 1, and attachment holes 3 are formed at predetermined positions such as corner portions of the outer peripheral rib 2 to attach the outer peripheral rib 2. The fuel tank 1 is attached to the vehicle body by bolting the use hole 3 and the vehicle body.
Furthermore, on the upper surface of the fuel tank 1, various hose attachment portions 6 for connecting a hose and the like for collecting the internal fuel vapor are formed.

As shown in FIGS. 2 and 3, a plurality of tanks are integrally formed on the tank bottom wall 12 of the tank outer wall 10 of the fuel tank 1 so as to protrude from the tank bottom wall 12 to the inside of the fuel tank 1. A protrusion 20 is formed. Since the tank protrusion 20 is formed on the tank bottom wall 12, even when the amount of fuel is reduced, the fuel protrusion can be suppressed by the tank protrusion 20, and the vibration sound generated when the fuel is swung can be reduced. Can do.

For this reason, when the fuel tank 1 is molded by blow molding or the like, the tank bottom wall 12 and the tank projection 20 can be molded simultaneously, which is efficient, and the tank projection 20 and the tank bottom wall 12 are formed integrally. Thus, there is no gap between the tank protrusion 20 and the tank bottom wall 12, and the air tightness of the fuel tank 1 can be maintained.

In the present embodiment, the individual tank protrusions 20 are preferably formed in a substantially quadrangular prism shape as shown in FIG.
The plurality of tank protrusions 20 are formed on the tank bottom wall 12 by forming a gap between the tank protrusions 20 and the tank protrusions 20 so as to be arranged in a row substantially perpendicular to the traveling direction of the vehicle. ing. For this reason, the tank bottom wall 12 can form the tank protrusion 20 widely with respect to the traveling direction of the vehicle, so that the fuel can be prevented from swinging over the entire width of the tank bottom wall 12.

And the row | line | column of the tank protrusion 20 is formed as several row | line | columns located in a line in the same direction as the advancing direction of a vehicle. In this embodiment, three rows of tank protrusions 20 are formed, but they can be formed in two rows or four or more rows.
As shown in FIG. 4, the rear row tank protrusions 20 are formed so as to face the gap portions between the front row tank protrusions 20 and the tank protrusions 20 with respect to the traveling direction of the vehicle.

For this reason, the fuel flowing from the gap between the tank protrusions 20 in the front row can flow between the tank protrusions 20 and the tank protrusions 20 and generates turbulent flow while generating the turbulent flow. 20 is surely hit, kinetic energy at the time of fuel oscillation is consumed, the fuel oscillation speed is effectively reduced, and the oscillation noise can be reduced.

In the present embodiment, three rows of tank protrusions 20 are formed on the front side with respect to the traveling direction of the vehicle on the tank bottom wall 12, and three rows are formed on the rear side with respect to the traveling direction of the vehicle on the tank bottom wall 12. Has been. However, the tank protrusion 20 is formed so as to be distributed over the two parts of the tank bottom wall 12 on the vehicle traveling direction side and the opposite direction side, but one side of the vehicle traveling direction side or the opposite side thereof. Can only be formed.

For this reason, the front and rear rows of tank projections 20 and the rear row of tank projections 20 and the rear row of tank projections 20 cause the front and rear sides of the fuel to swing in both directions. The front row is the rear row for reflection from the rear, and the rear row is the rear row for reflection, effectively reducing the fuel oscillation speed and reducing the oscillation noise. Can be made.

The tank protrusion 20 is formed so that the height is 1.5 to 2 cm, the width in the direction perpendicular to the traveling direction of the vehicle is 3 to 5 cm, and the depth in the same direction as the traveling direction of the vehicle is 2 to 3 cm. Is preferred. Since the tank protrusion 20 of this size is not large, the fuel rocking speed can be effectively reduced and the rocking noise can be reduced without greatly reducing the capacity of the fuel tank 1. .

A longitudinal section of the fuel flow with respect to the tank protrusion 20 is shown in FIG. The arrows in FIG. 5 indicate the flow of the fuel. The fuel flowing from the traveling direction of the vehicle is changed in flow to the protrusion front surface 21 of the tank protrusion 20 and moves upward, beyond the protrusion upper surface 24 of the tank protrusion 20. It flows and becomes a turbulent flow on the rear face 22 side of the tank protrusion 20, and consumes the kinetic energy at the time of fuel swing, effectively reducing the fuel swing speed and reducing the swing noise. it can.

When the height of the tank protrusion 20 is less than 1.5 cm, the height of the tank protrusion 20 is not sufficient, and the amount of fuel that hits the tank protrusion 20 when the fuel swings is small. When the turbulent flow in the longitudinal direction of the fuel flowing beyond the level does not sufficiently occur and the height of the tank protrusion 20 exceeds 2 cm, the capacity of the fuel tank 1 is reduced, which is useless.

The front surface 21 of the tank protrusion 20 in the vehicle traveling direction is preferably formed to be inclined 0 to 15 degrees rearward from the right angle with respect to the tank bottom wall 12. In this case, when the fuel oscillates, the fuel flows along the front surface 21 of the tank protrusion 20 in the vehicle traveling direction, and the fuel that further flows through the upper surface 24 of the protrusion 20 on the tank protrusion 20 reaches the rear surface 22 of the protrusion. The turbulent flow is generated and the kinetic energy is consumed by the turbulent flow, so that the rocking speed can be surely reduced and the rocking noise can be reduced.

When the front surface of the tank protrusion 20 in the traveling direction of the vehicle is tilted rearward from the right angle with respect to the tank bottom wall 12 by more than 15 degrees, the rear surface of the protrusion when the fuel flows beyond the upper surface 24 of the protrusion. 22 and turbulent flow is less likely to occur.

A cross section in the lateral direction of the fuel flow with respect to the tank protrusion 20 is shown in FIG. The arrows in FIG. 6 indicate the flow of the fuel. The fuel flowing from the traveling direction of the vehicle is changed in flow to the protrusion front surface 21 of the tank protrusion 20 and moves separately to the left and right. It flows along the side surfaces 23, 23 and becomes turbulent on the rear surface 22 side of the tank protrusion 20, consuming kinetic energy at the time of fuel oscillation, effectively reducing the fuel oscillation speed, Motion noise can be reduced.

When the width of the tank protrusion 20 is less than 3 cm, the area of the protrusion front surface 21 of the tank protrusion 20 is small, and sufficient lateral turbulence does not occur when the fuel swings, and the tank protrusion 20 has a width of 5 cm. When exceeding, the volume of the tank protrusion 20 becomes large, and the capacity of the fuel tank 1 decreases, which is useless. When the depth of the tank protrusion 20 is less than 2 cm, the fuel that has flowed in the lateral direction when the fuel is swung into the rear surface 22 of the protrusion does not sufficiently generate turbulence, and the depth of the tank protrusion 20 exceeds 3 cm. In some cases, the capacity of the fuel tank is reduced, which is useless.

The distance between the tank protrusions 20 arranged in the horizontal direction in the row of tank protrusions 20 is preferably 1 to 2 cm. Moreover, it is preferable that the space | interval between the row | line | column of the tank protrusion 20 and the row | line | column of the tank protrusion 20 is 1-2 cm. In this case, when the fuel swings between the tank protrusion 20 and the tank protrusion 20, a turbulent flow is generated on the rear surface of the tank protrusion 20 to reliably reduce the swing speed and reduce the swing noise. Can be made.

Further, when three rows of tank protrusions 20 are formed, the fuel that has flowed between the tank protrusions 20 in the front row hits the tank protrusions 20 in the second row, causing turbulence, The fuel that has flowed between the tank projections 20 in the second row hits the tank projections 20 in the third row and generates turbulence, thereby reliably reducing the oscillation speed and reducing the oscillation noise.

When the distance between the tank protrusions 20 in the row of the tank protrusions 20 is less than 1 cm, the amount of fuel flowing between the tank protrusions 20 is small when the fuel swings, and the kinetic energy when the fuel swings is small. When the amount of consumption is reduced and the distance between the tank protrusions 20 exceeds 2 cm, the generation of turbulent flow with respect to the fuel flowing between the tank protrusions 20 during the swinging is small, and the fuel swings. Less kinetic energy consumption.

DESCRIPTION OF SYMBOLS 1 Fuel tank 10 Tank outer wall 12 Tank bottom wall 20 Tank protrusion 21 Projection front 22 Projection rear surface

Claims (6)

In an automobile fuel tank having a tank outer wall formed of a thermoplastic synthetic resin,
Providing a plurality of tank protrusions integrally formed to protrude from the tank bottom wall of the tank outer wall to the inside of the fuel tank,
The plurality of tank protrusions are formed in a row arranged in a direction substantially perpendicular to the traveling direction of the vehicle with a gap between the tank protrusions and the tank protrusions. Are formed as a plurality of rows in the same direction as the traveling direction of the vehicle, and the tank projections in the rear row are opposed to the gaps between the tank projections and the tank projections in the front row, respectively. A fuel tank for automobiles formed as described above. The automobile fuel tank according to claim 1, wherein the tank protrusion is formed in a substantially quadrangular prism shape. Two to three rows of the tank protrusions are formed on the front side with respect to the traveling direction of the vehicle on the tank bottom wall, and two to three rows are formed on the rear side with respect to the traveling direction of the vehicle on the tank bottom wall. The automobile fuel tank according to claim 1 or 2. The tank protrusion has a height of 1.5 to 2 cm, a width in a direction perpendicular to the traveling direction of the vehicle of 3 to 5 cm, and a depth of 2 to 3 cm in the same direction as the traveling direction of the vehicle. Item 4. A fuel tank for automobiles according to any one of items 3 to 4. The distance between the tank protrusion and the tank protrusion in the tank protrusion row is 1 to 2 cm, and the distance between the tank protrusion row and the tank protrusion row is 1 to 2 cm. The fuel tank for automobiles according to any one of claims 4 to 5. The vehicle front surface according to any one of claims 1 to 5, wherein the front surface of the tank protrusion in the traveling direction of the vehicle is inclined to 0 to 15 degrees rearward from a right angle with respect to the tank bottom wall. Fuel tank.

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