JP2008248696A - Combination tank structure of vehicle fuel tank and urea water tank - Google Patents

Abstract

The urea water tank is less susceptible to the temperature rise of the fuel in the fuel tank, absorbs distortion of the tank due to volume expansion when the urea water is frozen, and can be easily confirmed even if a leak occurs. Another object of the present invention is to provide a combination structure of a vehicle fuel tank and a urea water tank having a safe structure in which liquids do not mix with each other.
A fuel tank for storing fuel for a vehicle and an exhaust gas by forming a plurality of liquid storage portions by providing a plurality of shielding plates for separating the longitudinal direction of a cylindrical tank body at intervals. In a tank structure in which a urea water tank that stores urea water as a purification reducing agent is integrally combined, a boundary between the fuel tank and the urea water tank is provided at a boundary between the fuel storage side and the urea water storage side. A space containing air is provided with a space between the shielding plate and an inspection hole or an inspection window is provided on the wall surface of the tank body at the position where the space is provided.
[Selection] Figure 1

Description

  The present invention relates to a combined tank structure of a vehicle fuel tank and a urea water tank in which a vehicle fuel tank and a urea water tank are combined together.

In recent years, exhaust gas purification devices called urea SCR systems have attracted attention due to stricter exhaust gas regulations.
The urea SCR system, the nitrogen oxides in the exhaust gas (NO _X) and a urea water by the catalytic reduction reaction, to purify nitrogen oxides, is intended to harmless. A tank for storing urea water used as a reducing agent is mounted on a vehicle and used like a vehicle fuel tank (hereinafter simply referred to as a fuel tank).
Therefore, conventionally, a dedicated urea water tank 1 for storing only urea water as shown in FIG. 5 is mounted on the vehicle separately from the fuel tank, or when it is difficult to secure a mounting location, The urea water tank is integrated into a space-saving tank so that the mounting space can be reduced and secured (Patent Documents 1 to 4).

Japanese Patent No. 3238416 JP 2006-105014 A JP 2005-29086 A JP 2005-054788 A

[Problems of the prior art]
When such a new urea water tank is added to the vehicle, it is difficult to secure a mounting space.
In addition, urea water used to reduce nitrogen oxides in the urea SCR system is a liquid that freezes when the temperature decreases and discharges ammonia when the temperature rises. In an environment where a vehicle equipped with urea water is used, it is necessary to manage at an appropriate temperature.

For example, when surplus fuel returns from the engine, the temperature may be as high as 100 ° C in some cases, so when the fuel tank and urea water tank are integrated, the liquid is simply shielded by the shielding plate. Even after the urea water absorbs the heat of the fuel, ammonia is discharged due to the temperature rise.
Also, if the urea water freezes at low temperatures, there is a concern about the damage of the tank due to the expansion of the volume of the urea water. In the worst case, if it is damaged in the tank, the damaged state cannot be confirmed, and an early response is possible. I couldn't get it.

  The present invention has been made in view of the above problems in the prior art, and the technical problem specifically set in order to solve this problem is that the urea water tank is affected by the temperature rise of the fuel in the fuel tank. Fuel for vehicles that has a safe structure that can be easily confirmed even if a leak occurs, and prevents liquids from mixing with each other. The object is to provide a combined tank structure of a tank and a urea water tank.

In order to identify a combination tank structure of a vehicle fuel tank and a urea water tank that effectively solves the above-mentioned problems in the present invention, all the matters recognized as necessary are covered and specifically configured. Means are shown below.
A first problem solving means relating to a combined tank structure of a vehicle fuel tank and a urea water tank is that a plurality of shielding plates for partitioning the longitudinal direction of the cylindrical tank main body are provided at intervals, whereby a plurality of liquids are provided. In the tank structure in which a fuel tank for housing fuel for a vehicle and a urea water tank for storing urea water as a reducing agent for exhaust gas purification are integrally combined, the fuel tank and the urea water tank A space containing air is provided between the shielding plate on the fuel storage side and the shielding plate on the urea water storage side, and the tank body wall surface where the space is provided is inspected. It is characterized by providing a hole.

The second problem-solving means relating to the combined tank structure of the vehicle fuel tank and the urea water tank is the same as that of the shielding plate for partitioning the longitudinal direction of the tank body, at the boundary between the fuel tank and the urea water tank. Each of the shielding plates other than the provided shielding plate on the urea water housing side is characterized in that a reinforcing uneven portion is formed on the flat portion.
The third problem solving means according to the combination tank structure of the vehicle fuel tank and the urea water tank is characterized in that the inspection hole includes a through hole through which air can freely pass through the space.
The fourth problem-solving means according to the combination tank structure of the vehicle fuel tank and the urea water tank is the same as that described above, in which the inspection hole is a part of the internal pressure adjusting mechanism that serves as a relief valve that exhausts only the increase in the pressure of the space. It is provided as a feature.

  In the first problem solving means according to the combined tank structure of the vehicle fuel tank and the urea water tank, the shielding plate on the fuel housing side and the shielding on the urea water housing side are arranged at the boundary for housing the fuel and the urea water. By providing a space in which air is introduced between the plate and an inspection hole in the wall surface of the tank body at the position where this space is provided, both the shielding plates on the fuel storage side and the urea water storage side, and the space between them Functions as a heat shield and volume fluctuation absorbing part, making it difficult for the urea water tank to be affected by the temperature rise of the fuel generated in the fuel tank, and absorbing the distortion of the tank due to volume expansion when the urea water freezes, The pressure of the tank is adjusted to approximately atmospheric pressure through the inspection hole to prevent damage to the tank, and even if a leak occurs, it can be easily confirmed from the inspection hole, and a safe structure that prevents mutual mixing of liquids. Can be realized.

In the second problem-solving means relating to the combined tank structure of the vehicle fuel tank and the urea water tank, the tank strength is improved by the shielding plates formed with the reinforcing irregularities, and the urea water is contained without forming the reinforcing irregularities. The side shielding plate absorbs the distortion of the tank due to the volume expansion when the urea water is frozen, and the volume change is absorbed by the change in the air volume in the space, thereby preventing the tank from being damaged or leaking.
In the third problem solving means relating to the combined tank structure of the vehicle fuel tank and the urea water tank, the outside air can freely enter and leave the space through the through hole in the inspection hole, and the pressure in the space is always kept at the outside air pressure. Can be kept equal.
In the fourth problem-solving means relating to the combined tank structure of the vehicle fuel tank and the urea water tank, the inspection hole is provided with a lid that serves as a relief valve that exhausts only the pressure increase in the space that is a part of the internal pressure adjustment mechanism. As a result, the inspection hole can also serve as an internal pressure adjusting mechanism, the space pressure can be adjusted to be substantially constant, and dirt such as dust and water droplets can be prevented from entering the space from the outside.

Hereinafter, the best embodiment according to the present invention will be described in detail.
However, this embodiment is specifically described for better understanding of the gist of the invention, and does not limit the content of the invention unless otherwise specified.
The same components as those described in the prior art are denoted by the same reference numerals, and a specific description thereof is omitted.

〔Constitution〕
The structure of the combination tank 10 of the vehicle fuel tank and the urea water tank in this embodiment is, as shown in FIGS. 1 to 3, a shielding plate 10b that divides both ends of the cylindrical tank body 10a from the longitudinal direction inside. , 10b are provided at a necessary interval. A plurality of liquid storage portions are formed inside the tank body 10a partitioned by the shielding plates 10b,..., 10b, and one of the liquid storage portions is a vehicle fuel tank (hereinafter simply referred to as a fuel tank) that stores fuel. 11) and the other one is a urea water tank 12 for storing urea water.

In the fuel tank 11, baffle plates 11 a and 11 a for suppressing fuel shaking due to vehicle vibration are arranged in parallel with the shielding plates 10 b and 10 b forming the end face of the fuel tank 11 to supply fuel to the engine side. A refueling pipe 11b and a return pipe 11c for returning surplus fuel from the engine side are connected, and an inlet 11d for refueling is opened obliquely upward in the tank. A small recess 11e into which the tip of the fuel supply pipe 11b enters is formed at the center of the bottom surface of the fuel tank 11. This recess 11e is the lowest position of the fuel tank 11, and this recess 11e is an oil in a state where fuel is always accumulated. Molded to the size and shape required for the pool.
The urea water tank 12 includes a liquid meter for monitoring the liquid volume, a simple heat exchanger for keeping or thawing the urea water, a necessary supply of measuring equipment and piping such as a liquid supply pipe and a liquid return pipe. The piping unit 12a for assembling and accommodating the piping unit 12a is assembled, and the inlet 12b for supplying urea water is opened obliquely upward of the tank.

One of the two shielding plates 10b and 10b provided at the boundary between the tanks 11 and 12 for containing fuel and urea water serves as a shielding plate (fuel shielding plate) on the fuel containing side, and the other contains urea water. This is the side shielding plate (urea water shielding plate). A space 13 is formed by filling the space between the shielding plates 10b and 10b with air.
The wall surface of the tank main body at the position where the space 13 is provided is provided with an inspection hole 14 for looking into the air layer. The inspection hole 14 is formed as a simple hole and is a through hole for exhausting air when the pressure increases. An inspection window that also serves as an internal pressure adjustment mechanism that is provided with a lid (not shown) that is a part of the internal pressure adjustment mechanism in which a relief valve is formed by providing an internal pressure adjustment hole or a window made of a transparent plate material.

The shielding plate 10b is a single plate member, and the peripheral portion of the plate member is bent with the same width in the same direction at a substantially right angle to form an edge 16 having substantially the same height to form a plate shape. A wide X-shaped convex portion 17 that is convex in the same direction as the direction in which the edge 16 is formed from the planar portion is formed on the planar portion formed in a dish shape of 10b.
Of the shielding plate 10b of the urea water tank 12, the shielding plate 10c located on the urea water tank 12 side of the fuel tank 11 and the shielding plate 12c facing each other across the space 13 (a kind of shielding plate 10b is uneven on the flat portion) (The shape having no portion) is a flat shape that does not form the convex portion 17 on the flat portion, and the shielding plate 12c is formed in a shape that is easily bent in the thickness direction of the flat portion.

Further, the baffle plate 11a, like the shielding plate 10b, forms an edge 16 having substantially the same height and a wide X-shaped convex portion 17, and is not processed by the convex portion 17, and is an X-shaped convex portion. A circular hole 18 serving as a fuel passage is formed in the surface where the rod-shaped portion 17 is not formed and the central portion of the X-shaped convex portion 17.
The tank body 10a, the shielding plate 12c, and the shielding plate 10b constituting the combination tank 10 are joined without gaps by welding, the baffle plate 11a is joined at several points by intermittent welding on the surface contacting the tank body 10a, and the pipes are The tank body 10a is joined by brazing. Since urea water has high permeability, a simple heat exchanger for keeping or thawing the urea water is installed in the tank body 10a via a packing. The material used is a tank body, the shielding plate 10b including the shielding plate 12c, and the materials of the related parts of the urea water tank 12 are made of stainless steel in order to prevent corrosion by urea water.

[Function and effect]
In the combined structure of the vehicle fuel tank and the urea water tank in such an embodiment, it is possible to save space by forming the single tank body 10a by integrating the two tanks, and the fuel tank and the urea water tank. Since the shielding plates 10b and 12c provided between the tank and the tank 13 are in the state of sandwiching the space 13, the influence of the temperature rise of the fuel can be suppressed by the space 13, and ammonia generation of urea water can be prevented.
Further, since the shielding plate 12c of the urea water tank 12 can be easily recessed or expanded, the shielding plates 10b, 12c and the space 13 function to absorb the distortion of the tank due to volume expansion when the urea water is frozen, The tank can be prevented from being damaged when the urea water is frozen.

Further, by providing the internal pressure adjusting hole or the inspection hole 14 which also functions as the internal pressure adjusting mechanism on the wall surface of the tank body 10a where the space 13 is located, it is possible to easily check for leaks when the tank is damaged or when the vehicle is regularly inspected. . Even in the event of a leak, there are shielding plates 10b, 10b serving as the wall surfaces of the end face of the tank portion between the fuel and urea water accommodating portions, and a space 13 is formed between them. Therefore, as long as both the shielding plates 10b and 10b are not damaged at the same time, it is possible to prevent the liquids from mixing with each other.
Further, since the inspection hole 14 is formed with an internal pressure adjusting hole having a simple hole or a common inspection hole 14 to which a lid which is a component of the internal pressure adjusting mechanism is attached, the volume expansion at the time of freezing of urea water is formed. The pressure of the space 13 pressed by the shielding plate 12c that has absorbed the pressure can be released to adjust the pressure, and dirt such as dust and water droplets from the outside can be prevented from entering the space.

[Another aspect]
In the embodiment, the fuel tank and the urea water tank are arranged side by side and formed integrally, but the case where these are arranged vertically and integrated is specifically described as another mode.
The structure of the combination tank 20 of the vehicle fuel tank and the urea water tank in another aspect is as shown in FIG. 4 in which a fuel tank 11 and a urea water tank 12 that are liquid storage layers are stacked one above the other, 20 may be formed in a vertically arranged format.
The material of the tank body may be a steel tank coated with a resin capable of preventing corrosion by urea water in addition to stainless steel.

  In such another embodiment, when the combination tank structure is vertically arranged, the center-of-gravity directions of the liquids coincide with each other, so that vibration input from the vehicle to the tank body due to variations in liquid consumption can be absorbed in a balanced manner. Thus, stable running performance can be provided to the vehicle.

It is a perspective see-through explanatory view showing a combined tank structure of a vehicle fuel tank and a urea water tank according to an embodiment of the present invention. It is a front view which shows the combination tank structure of the fuel tank for vehicles same as the above, and a urea water tank. FIG. 2 is an enlarged front perspective view showing a portion A of FIG. 1 in the combined tank structure of the vehicle fuel tank and the urea water tank. It is a front view which shows the combination tank structure of the fuel tank for vehicles and the urea water tank which concerns on another aspect of this invention. It is a perspective view which shows the urea water tank single-piece | unit in the past.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Urea water tank 10 Combination tank 10a of vehicle fuel tank and urea water tank Tank main body 10b Shielding plate 11 (Vehicle) Fuel tank 11a Baffle plate 11b Refueling pipe 11c Return pipe 11d Inlet 11e Recess 12 Urea water tank 12a Piping Unit 12b Entrance 12c Shield plate 13 Space 14 Inspection hole (or inspection window)
16 Edge 17 Projection 18 (Circular) Hole

Claims (4)

A plurality of shielding plates for partitioning the longitudinal direction of the cylindrical tank body are provided at intervals, thereby forming a plurality of liquid storage portions and a fuel tank for storing vehicle fuel and a reducing agent for exhaust gas purification As a tank structure that integrally combines with a urea water tank that contains urea water,
At the boundary between the fuel tank and the urea water tank, a space containing air is provided between the shielding plate on the fuel storage side and the shielding plate on the urea water storage side, and this space is provided. The tank structure of the vehicle fuel tank and the urea water tank is characterized in that an inspection hole is provided in the wall of the tank body at a different position.   Among the shielding plates that partition the longitudinal direction of the tank body, each shielding plate other than the shielding plate on the urea water storage side provided at the boundary between the fuel tank and the urea water tank has a reinforcing uneven portion on the flat surface portion. The combined tank structure of a fuel tank and a urea water tank according to claim 1, wherein:   2. The combined tank structure of a vehicle fuel tank and a urea water tank according to claim 1, wherein the inspection hole includes a through hole through which air can freely pass through the space.   2. The combination of a vehicle fuel tank and a urea water tank according to claim 1, wherein the inspection hole includes a cover serving as a relief valve that exhausts air by an amount corresponding to an increase in the pressure of the space. Tank structure.

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