KR20120059000A - Drain structure of vehicle having SCR system to purify exhaust gas - Google Patents

Abstract

PURPOSE: A structure of a drain unit of an aqueous urea solution tank for vehicles equipped with a SCR(Selective Catalytic Reduction) system for purifying exhaust gas is provided to prevent a water leakage from an O-ring because metallic core materials are not thermally deformed, and formed into the circular shape. CONSTITUTION: A structure of a drain unit of an aqueous urea solution tank(1) for vehicles equipped with an SCR(Selective Catalytic Reduction) system for purifying exhaust gas comprises a female-threaded nut(3) and a drain plug(4). The tank is made of plastic materials. The female-threaded nut is inserted into a drain hole(8) of the tank. The female-threaded nut comprises a metal core(6) and an insert member. The metal core comprises a female screw(5). The insert member is integrated with an outer surface of the metal core, and made of the same plastic materials as the tank. The female-threaded nut is made of different kinds of composite materials. The drain plug having male threads(9) is inserted into the female screw of the metal core with a screw joining.

Description

Drain structure of vehicle having SCR system to purify exhaust gas

The present invention relates to an improvement in the drain structure of a urea water tank of a vehicle equipped with an SCR system for exhaust gas purification.

In general, automobiles can be classified into gasoline, diesel, and LPG vehicles according to the type of fuel used. Among them, diesel vehicles have high fuel efficiency, high power and high load operation, and low fuel costs, and thus the demand is continuously increasing. It is true.

However, since the exhaust gas of the diesel vehicle contains more harmful substances such as carbon monoxide, nitrogen oxides and particulate matters than the gasoline vehicle, soot filtration apparatuses for treating the pollutants to purify the exhaust gas have been developed in various ways.

When the fuel such as petroleum is combusted, a large amount of combustion gas harmful to the human body is generated, and post-treatment technology for purifying these harmful gases is required. The post-treatment technique is roughly divided into a wet method and a dry method, and particularly, a dry method has been actively studied. The dry process involves selective non-catalytic reduction (SNCR), which selectively reduces nitrogen oxides to nitrogen and water at high temperatures (above 850 ° C) without the use of catalysts, and nitrogen oxides using catalysts. And Selective Catalytic Reduction (SCR) for reducing to water. The former has the advantage that 50% or more of nitrogen oxides can be removed at a relatively low cost, but the unreacted ammonia discharged forms ammonium salts, etc., so that it can be plugged into the device behind the SCR reactor. It may cause corrosion and there is difficulty in operation because the operating temperature band is narrow. Therefore, the selective catalytic reduction method (hereinafter, referred to as SCR) has been in the spotlight in terms of economic and technical aspects in removing nitrogen oxides generated from fixed sources.

The functional classification used in the vehicle of such a particulate filter includes DOC (Diesel Oxidation Catalyst) which converts hydrocarbon and carbon monoxide components in exhaust gas into water and carbon dioxide through oxidation by a catalyst, respectively. Catalyzed Diesel Particulate Filter (CPF), which collects particulate matter contained in exhaust gas and combusts it by heat of exhaust gas, and nitrogen oxides contained in exhaust gas by using nitrogen and oxygen. It can be divided into SCR device (Selective Catalytic Reduction) and the like to reduce to.

3 is a schematic conceptual view of a general soot filtration system.

As shown in Fig. 3, the exhaust pipe is equipped with a DOC catalyst 10, a CPF filter 20, and an SCR device 30 in order from the exhaust manifold (not shown) in order to continuously purify harmful substances in the exhaust gas. Is processed.

That is, while exhaust gas passes through the DOC catalyst 10, hydrocarbons and carbon monoxide are purified, particulate matter is filtered while passing through the CPF filter 20, and nitrogen oxide is finally reduced while passing through the SCR apparatus 30. The pollutants are purified in such a way.

At this time, the front end of the SCR device 30 is equipped with a spray tube 40 for injecting an oxidant, and the oxidant injected through the spray tube 40 is urea (Urea) or ammonia is used to the exhaust gas by the oxidant The contained nitrogen oxides undergo a reduction reaction and decompose into water and nitrogen.

As mentioned above, in the case of the SCR apparatus, a urea water storage tank is required because urea must be injected with an oxidant.

4 shows a tank 50 for storing urea water, and at the lower end of the tank 50, a drain portion 60 for discharging urea is formed, which is shown in FIG. The female screw nut 62 made of HDPE of the same material is inserted into the hole 61 of the tank 50 made of the HDPE material, and the drain plug having the male screw 63 formed on the female nut 62 is formed. (64) is fastened so that the urea water can be drained, and the O-ring 65 is interposed to prevent leakage between the female screw nut 62 and the drain plug 64.

However, according to the conventional technique described above, the female screw nut 62 is inserted into the hole 61 of the tank main body 50 when blow molding the tank main body 50, so that the plastic resin is melted for this purpose. The mold is formed at a temperature of about 220 ° C. in order to bring it into a state of heat. At this time, the thermal deformation of the part to be inserted into the high temperature prevents the maintenance of the source and causes distortion. Thus, when the drain plug 64 is assembled, the O-ring (65) ) Was causing the leak.

Accordingly, the present invention has been proposed in view of the above problems, and its object is to provide a structure capable of preventing leakage of the drain portion of a tank for storing urea water of a vehicle having an SCR system for exhaust gas purification. have.

In order to achieve the above object, the present invention provides a drain structure of a tank for storing urea water of a vehicle having an SCR system for purifying exhaust gas, wherein the tank is formed of a plastic material, and is formed in a drain hole of the tank. The female screw nut is mounted, but the female screw nut is integrally formed by insert injection into the outer core of the metal core with the female screw and the metal core, and is formed of a heterogeneous composite material by an insert member formed of the same plastic material as the tank. And a drain plug having a male screw in the female screw of the metal core member is mounted by screwing.

In addition, according to a preferred embodiment of the present invention the tank is characterized in that it is formed of HDPE material.

In addition, according to a preferred embodiment of the present invention, the metal core of the female screw nut is formed of SUS material.

The female screw nut may be mounted to be integral with the tank body by an insert when the tank is blow molded.

In addition, an O-ring for preventing leakage is interposed between the female screw nut and the drain plug.

In addition, the metal member and the insert member of the female screw nut is characterized in that it has a complicated cross-sectional coupling structure so as to prevent separation from each other.

According to the present invention by injection molding the female screw nut with a heterogeneous composite material of metal and plastic and blow injection mounted in the urea water storage tank body, even if the high injection temperature of 220 ℃ or more is maintained inside the insert product Since the core material maintains the original shape without causing thermal deformation, there is an effect that no leakage occurs at the O-ring site when the drain plug is assembled.

1 is a cross-sectional view showing a female screw nut of a heterogeneous composite material that is an insert according to the present invention.
Fig. 2 is a half sectional view of the main portion showing the assembling structure of the drain portion of the urea water storage tank according to the present invention.
3 is a schematic conceptual view of a general soot filtration system.
4 is a view showing a tank for storing urea water in the SCR apparatus.
Fig. 5 is a half sectional view of the main portion showing the assembling structure of the drain portion of the tank for storing the conventional urea water.

DETAILED DESCRIPTION Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings in order to fully understand the present invention. Embodiment of the present invention may be modified in various forms, the scope of the invention should not be construed as limited to the embodiments described in detail below. This embodiment is provided to more completely explain the present invention to those skilled in the art. Therefore, the shapes and the like of the elements in the drawings can be exaggeratedly expressed to emphasize a clearer description. It should be noted that the same members in each drawing are sometimes shown with the same reference numerals. In addition, detailed descriptions of well-known functions and configurations that are determined to unnecessarily obscure the subject matter of the present invention are omitted.

Hereinafter, with reference to the accompanying drawings illustrating a preferred embodiment of the present invention, the drain structure of the urea water tank of the vehicle provided with the SCR system for the exhaust gas purification of the present invention will be described in detail.

1 is a cross-sectional view showing a female screw nut made of a heterogeneous composite material which is an insert according to the present invention, and FIG. 2 is an essential part showing the assembling structure of the drain portion of the urea water storage tank according to the present invention. Represents a tank for the storage of urea water.

The lower surface of the urea water storage tank 1 is provided with a drain portion 2 for discharging urea water, the drain portion 2 is a female screw nut (3), the drain plug (4) and the O-ring (5) ) Is configured to include.

As shown in FIG. 2, the female threaded nut 3 is integrally manufactured by insert injection into the metal core 6, which is formed with the internal thread 5 and positioned inside the insert, and on the outer circumference of the metal core 6. It is formed of an insert member 7 made of plastic material, and preferably, the metal core material 6 is preferably made of SUS (stainless steel) material having strong corrosion resistance, and has a complicated cross-sectional coupling structure so as not to deviate from each other.

The female screw nut 3 formed of a composite material of a heterogeneous material as described above is inserted into the drain hole 8 of the tank 1 when blow molding the tank 1, wherein the insert easily has affinity. The tank 1 and the insert member 7 are formed of the same plastic material, and preferably, HDPE material is used.

When the female screw nut 3 is insert-mounted to the tank 1, the male screw 9 of the drain plug 4 is screwed into the female screw 5 to be mounted.

 According to the present invention, the inside of the female screw nut is formed of a metal material, and the outside is integrally manufactured in a shape in which an insert member made of a material such as a tank is enclosed, so that even when high temperature acts upon inserting and mounting the female screw nut to the tank body, the metal core material The inserts are kept round without causing heat deformation, which prevents leakage through the O-ring when the drain plug is mounted.

Embodiments of the present invention described above are merely exemplary, and those skilled in the art will appreciate that various modifications and equivalent other embodiments are possible therefrom. Therefore, it will be understood that the present invention is not limited to the forms mentioned in the above detailed description. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims. It is also to be understood that the invention includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

1 tank 2 drain part
3: female thread nut 4: drain plug
5: female thread 6: metal member
7: insert member 8: hole
9: male thread

Claims (6)

In the drain structure of the tank for storing the urea water of the vehicle having an SCR system for the exhaust gas purification, the tank is formed of a plastic material, the female screw nut is mounted in the drain hole of the tank, the female screw nut is female screw It is integrally formed by insert injection into the outer core of the metal core material and the metal core material provided with, and formed of a heterogeneous composite material by the insert member formed of the same plastic material as the tank, the male thread of the metal core material is provided with a male screw A drain structure of a urea water tank of a vehicle equipped with an SCR system for exhaust gas purification, wherein one drain plug is mounted by screwing.
The drain structure of a urea water tank of a vehicle according to claim 1, wherein the tank is made of HDPE.
The drain structure of the urea water tank of a vehicle having an SCR system for exhaust gas purification according to claim 1 or 2, wherein the metal core of the female screw nut is made of SUS material.
The drain of the urea water tank of a vehicle having an SCR system for exhaust gas purification according to claim 1, wherein the female screw nut is mounted to the tank body by an insert when blow molding the tank. Wealth structure.
2. The drain structure of a urea water tank of a vehicle having an SCR system for purifying exhaust gas, wherein an O-ring for preventing leakage is interposed between the female screw nut and the drain plug.
The drain of the urea water tank of a vehicle having an SCR system for exhaust gas purification according to claim 1, wherein the metal member and the insert member of the female screw nut have a complicated cross-sectional coupling structure to prevent them from being separated from each other. rescue.

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