KR20170070407A - Urea tank integrated with feul tank and method for manufacturing it - Google Patents

Abstract

The present invention relates to a urea tank integrated with a fuel tank,
The urea tank 10 is formed of a tank 21 formed of aluminum on the outside and a synthetic resin layer 23 having stable characteristics with respect to the urea water formed on the inner surface of the urea tank 10 to a predetermined thickness, The fuel tank 21 is integrally joined to the fuel tank 11 of the same material, thereby solving the difficulty in the layout of the conventional urea tank and forming the urea tank integrally with the metal fuel tank with the synthetic resin material It is effective in reducing weight and cost.
Further, according to the present invention, the urea tank is rotated at a predetermined temperature, time, and rotational speed while rotating the urea tank using the rotational molding method, whereby the resin layer is integrated with excellent fusion uniformity on the inner surface of the outer tank of aluminum.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a urea tank integrated with a fuel tank,

The present invention relates to a urea tank and a method of manufacturing the same. More particularly, the present invention relates to a urea tank and an urea tank integrally formed with a fuel tank, and a urea tank made of a synthetic resin material stable in urea water, To a fuel tank of a fuel tank.

Recently, as concern about the global environment has increased, harmful substances emitted by automobiles are considered to be the main culprit in deteriorating air quality in urban areas. In order to reduce relatively high emissions of nitrogen oxides and particulate matter (PM) among diesel vehicle emissions, the emission standards for certification both at home and abroad are being strengthened.

As a result, with regard to PM emissions, EU legislation enforcing the adoption of a soot filter (DPF) to make the emissions close to zero gradually strengthened every five years. In 1992, EURO1 introduced carbon monoxide (CO) (CO) of 4.5 g / kWh, 1.1 g / kWh of hydrocarbons (HC), 8 g / kWh of nitrogen oxides (NOx) and 0.36 g / kWh of particulate matter (PM) kWh of hydrocarbons, 0.13 g / kWh of hydrocarbons, 0.4 g / kWh of nitrogen oxides (NOx) and 0.01 g / kWh of particulate matter (PM).

In order to meet these regulations, the application of precise high-pressure injection (CRDI, common rail system) of fuel, DOC (diesel oxidation catalyst), EGR (exhaust gas recirculation), DPF (diesel particulate filter), SCR Reduction system). However, in order to reduce the emission of diesel vehicles in the future, the DeNOx system will be especially studied and developed. Among these systems, the system exhibiting the highest nitrogen oxide reduction efficiency is SCR System.

In order to supply the urea used in such an SCR system, additional installation of the urea tank in the vehicle chassis is required to secure the layout space of the vehicle and to minimize the weight and cost increase due to the additional installation of the urea tank.

On the other hand, as disclosed in Korean Patent Registration No. 10-0370805 (registered Jan. 21, 2003), as schematically shown in FIG. 1, a vehicle tank having a reducing agent working exhaust gas purifying device is further provided with a reducing agent tank A tank 6 for containing the fuel K and a tank 8 for containing the reducing agent R are combined into one module 2 which is fixed to the fixing holder 14 by a single The fuel tank and the reducing agent tank are arranged in this order, separated by the common wall 4, and the wall 4 is made of a good thermally conductive metal.

However, due to the nature of the urea water, there is a problem that the metal urea tank can not be used, so that a urea tank made of a more stable material is required for the urea, but a metal tank made of, for example, an Al alloy and a synthetic resin urea tank are integrated Is preferable for the layout, but it has been difficult to manufacture the tanks of the different kinds in this way.

As another example, Korean Patent Registration No. 10-1036574 (registered May 17, 2011) discloses a structure in which a HWL tank and a sub muffler are combined with a fuel tank to form one structural unit, Frame, but the integrated structure is complicated, resulting in an increase in manufacturing cost.

Domestic patent registration No. 10-0370805 (registered on Jan. 21, 2003) Domestic patent registration No. 10-1036574 (registered on May 17, 2011)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a urea tank having an improved structure by integrating a fuel tank made of a metal and a urea tank made of a synthetic resin to solve the problems in the layout of the urea tank, will be.

It is another object of the present invention to provide a method of manufacturing a synthetic resin material by integrating a urea tank of a synthetic resin into a metal fuel tank.

In order to achieve the above object, the urea tank integrated with the fuel tank according to the present invention is formed of a synthetic resin layer having stable characteristics with respect to urethane water, And the tank portion of the urea tank is integrally joined to a fuel tank of the same material.

The tank portion of the urea tank has a protruded rim at an end portion thereof joined to a fuel tank of the same material, and the rim is welded to one end portion of the fuel tank.

The concave recess is a space for dissipating heat to prevent heat generated during welding with the fuel tank from being transmitted to the inside of the tank to prevent the synthetic resin layer from affecting the inside of the rim.

According to the present invention, there is provided a method of manufacturing a urea tank integrated with a fuel tank,

(S1) fixing an outer tank made of aluminum to be connected to the fuel tank to the rotary jig,

(S2) of injecting the material powder of the synthetic resin layer (23) into the outer tank in a quantity determined in consideration of the thickness for forming the synthetic resin layer,

A step (S3) of installing a jig to which the outer tank, into which the LLDPE powder is charged, is fixed, so as to rotate the outer tank,

(S4) for shaping the LLDPE layer in the outer tank while rotating the jig to which the outer tank having the LLDPE powder inserted therein is rotated in the oven in the step (S3)

(S5) removing the rotatably molded urea tank from the oven and cooling at room temperature,

 And a step (S6) of welding the cooled urea tank with the fuel tank in the step (S5).

The molding temperature in the rotation molding step S4 for molding the LLDPE layer in the outer tank is in the range of 290 to 310 占 폚 and the molding is preferably carried out while rotating in the range of 23 to 35 rpm in the step S4.

It is also preferable that the rotation and heating time in the step (S4) and the cooling time of the molded urea tank after stripping in the oven in the step (5) are 25 to 30 minutes.

According to the present invention, the urea tank is integrally provided with the metal fuel tank to solve the difficulty in the layout of the conventional urea tank, and the urea tank is formed integrally with the metal fuel tank by the synthetic resin material, It is effective.

In addition, according to the present invention, the resin layer is integrated with excellent fusion uniformity on the inner surface of the outer tank of aluminum by molding in a predetermined temperature, time, and rotational speed while rotating in an oven using a rotary molding method.

1 is a cross-sectional view schematically showing a configuration in which a conventional fuel tank and a urea tank are integrated into a single module 2. Fig.
2 is a schematic sectional view showing a structure in which a fuel tank and a urea tank are integrated according to the present invention.
3 is a partially enlarged cross-sectional view of Fig.
4 is an exploded view of Fig.
5 is a schematic process diagram of a method of manufacturing a urea tank integrated with a fuel tank according to the present invention.
Fig. 6 is a graph of fusing degree according to the molding temperature during rotational molding in the manufacturing method of the present invention.
7 is a graph of fusion uniformity according to rotation speed during rotational molding in the manufacturing method of the present invention.
FIG. 8 is a graph showing the uniformity of fusing with rotation cooling, idling, and heating time during rotational molding in the manufacturing method of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown.

2 to 4, the fuel tank integrated type urea tank 10 according to the present invention comprises a fuel tank 11 made of an aluminum material, and a urea tank 20 formed separately from the fuel tank and integrally joined and integrated .

According to the present invention, the urea tank 20 includes a tank portion 21 made of aluminum or an aluminum alloy, and a synthetic resin layer 23 formed on the inner surface of the tank portion 21 to a predetermined thickness. The synthetic resin layer 23 on the inside of the tank portion is made of a synthetic resin having stable characteristics with respect to urea water, and for example, a linear low density polyethylene (LLDPE) resin is preferable.

The synthetic resin layer 23 is formed on the tank portion 21 of the urea tank 20 by using a rotary molding method, and a detailed description thereof will be described later.

A rim 22 is formed at an end portion of the tank portion 21 made of an aluminum alloy material constituting the outside of the urea tank 20 and joined to the fuel tank 11 made of the same material so as to form a concave recessed portion 24, And the rim 22 is integrally formed with the fuel tank and the urea tank by welding with one end of the fuel tank 11.

The rim 22 is formed to be folded and protruded at the end of the tank portion 21. The recessed recessed portion 24 formed inside the rim 22 is formed in such a manner that heat generated during welding with the fuel tank flows into the tank 22, (21) so as not to affect the synthetic resin layer (23).

The holes for installing these components are formed in the urea tank 20 by a synthetic resin layer 23 inside the tank portion of the metal by a rotary molding method, A core is installed in a corresponding hole formed in the tank portion to form a hole for attaching a component to the synthetic resin layer. In this case, a hole for installing a component such as a sensor is inserted in advance, and a synthetic resin layer , A gap through which the urea can leak between the bracket and the synthetic resin layer is fundamentally prevented.

FIG. 5 schematically shows a method of manufacturing a urea tank in which a synthetic resin layer is integrally formed according to the present invention.

The urea tank for integrating the fuel tank according to the present invention uses a rotary molding method to integrate different kinds of materials.

In step S1, an outer tank made of aluminum or its alloy to be joined to the fuel tank is fixed to the rotary jig, and then in step S2, a synthetic resin layer 23 material, preferably LLDPE powder, , A quantity determined in consideration of the thickness for forming the synthetic resin layer, and a jig to which the external tank filled with the LLDPE powder is fixed is installed in the rotating body so as to rotate the external tank in step S3.

Then, the step S4 is a step of rotationally molding a jig to which the external tank having the LLDPE powder charged therein is fixed in the oven by rotating the external tank fixed to the jig in the oven by LLPDE The molten LLDPE resin is welded to the inside surface of the outer tank of the metal and molded. At this time, the molding temperature and the rotational speed are determined within a range in which preferable fusing uniformity is obtained according to the thickness of the synthetic resin layer of the LLDPE resin to be obtained.

  The LLDPE resin starts to melt at 170 DEG C, but according to the test, the molding temperature is determined in a temperature range in which the required uniformity of deposition is 70% as shown in Table 1, and is preferably 290 DEG C or higher in Table 1, As can be seen from the graph of fusion strength according to the molding temperature obtained by the test, when the temperature is higher than 310 ° C., the uniformity is lowered because the viscosity is increased.

Table 1. Molding temperature test results for uniformity of fusion of LLDPE resin and aluminum

Also, even if the LLDPE resin layer is melted in the outer tank by heating in an oven to form a synthetic resin layer, preferably an LLDPE resin layer, on the inner surface of the metal outer tank, the LLDPE resin layer formed on the inner surface of the outer tank, The thickness of the resin layer is influenced. According to the test, the rotation speed and the fusion uniformity data as shown in Table 2 below are obtained as shown in Table 2 below.

Table 2. Filling uniformity test results according to rotation speed during LLDPE resin molding

The uniformity of fusing with respect to the rotational speed at a temperature of 310 DEG C was obtained by the graph as shown in FIG. 7, where it was judged that the fusing uniformity was the highest at a rotational speed of 25 rpm and was possible at 23 to 35 rpm, There was a run-down phenomenon. Therefore, the rotation speed is preferably 23 to 35 rpm.

In addition, the molding time of the LLDPE resin and the uniformity of the fusion of aluminum were obtained on a case-by-case basis. As a result, data were obtained by cooling time, idling time and heating time in the molding time while keeping the temperature and rotation speed at the time of molding at 310 ° C / 25 rpm. And the uniformity of fusion according to the molding time was plotted. As a result, the graph of FIG. 8 was obtained.

Table 3. Fusion uniformity test results according to LLDPE resin molding time

As a result, the highest fusion uniformity is obtained in tests 1 and 10 having the same heating / idling / cooling time. Therefore, it is the most productive to perform the same heating time, idling time and cooling time, It is confirmed that the molding condition is performed at a minimum cost. Therefore, it is preferable that the cooling, idling and heating time are equally 25 minutes to 30 minutes.

Then, as step S5, the rotomolded urea tank in the oven is removed from the oven and cooled at room temperature, at which time the cooling time is equal to the idle time and the heating time, as determined to be preferred in the above Table 3 and Figure 8 .

The cooled urea tank in step S5 is welded to the fuel tank (step S6). At this time, the welded portion is the rim 22 of the end portion of the shape of the tank portion 21 which is made of an aluminum alloy and forms an outer side of the urea tank 20, such as a fuel tank, The heat generated during the welding with the fuel tank in the concave recessed portion 24 formed inside the rim 22 is eliminated without being transferred to the inside of the tank portion 21 to affect the synthetic resin layer 23 inside the tank portion .

Further, according to the present invention, when the synthetic resin is formed by fusion molding the synthetic resin layer on the inner surface of the outer tank by the rotary molding method according to the present invention, the bracket is previously fixed to the outer tank at the position of the hole for installing the sensor, The integral of the bracket with the synthetic resin layer is increased, and there is no fear of leakage of urea water.

The present invention can be applied to a urea tank for receiving and supplying urea that provides nitrogen oxide and particulate matter (PM) in a diesel vehicle.

11: fuel tank 20: urea tank
21: tank part 22: rim
23: synthetic resin layer 24:

Claims (7)

In a urea tank integrated with a fuel tank,
The urea tank 10 is formed of a tank portion 21 formed of aluminum on the outside and a synthetic resin layer 23 having stable characteristics with respect to urea water formed on a predetermined thickness on the inner surface thereof,
Characterized in that the tank portion (21) of the urea tank is joined to the fuel tank (11) of the same material and integrated.
The method according to claim 1,
A protruding rim 22 is formed at an end of the tank 21 of the urea tank where the tank 21 is joined to the fuel tank 11 of the same material and the rim 22 is welded to one end of the fuel tank 11 Wherein the fuel tank is connected to the urea tank.
3. The method of claim 2,
The concave grooves 24 are formed inside the rim 22 so that the heat generated during the welding with the fuel tank is transmitted to the interior of the tank 21 to form the synthetic resin layer 23, And a space for dissipating the heat of welding for preventing the heat from being applied to the urea tank.
Urea tanks use rotational molding to integrate different materials.
(S1) fixing an outer tank made of aluminum to be connected to the fuel tank to the rotary jig,
(S2) of injecting the material powder of the synthetic resin layer (23) into the outer tank in a quantity determined in consideration of the thickness for forming the synthetic resin layer,
A step (S3) of installing a jig to which the outer tank, into which the LLDPE powder is charged, is fixed, so as to rotate the outer tank,
(S4) for shaping the LLDPE layer in the outer tank while rotating the jig to which the outer tank having the LLDPE powder inserted therein is rotated in the oven in the step (S3)
(S5) removing the rotatably molded urea tank from the oven and cooling at room temperature,
And a step (S6) of welding the cooled urea tank with the fuel tank in the step (S5).
5. The method of claim 4, wherein the forming temperature in the rotational molding step (S4) for molding the LLDPE layer in the outer tank is in the range of 290 to 310 占 폚.
The method according to claim 4 or 5, wherein the step (S4) is carried out while rotating in the range of 23 to 35 rpm.
6. The method according to claim 4 or 5, wherein the rotation and heating time in the step (S4) and the cooling time of the molded urea tank after being removed from the oven in the step (5) are 25 to 30 minutes Wherein the fuel tank is integrally formed with the fuel tank.

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