KR20180037469A - Exhaust gas recirculation Valve assembly - Google Patents

Abstract

Disclosed is an exhaust gas recirculation (EGR) valve assembly applied to an EGR system for reducing nitrogen oxides (NO_x). The EGR valve assembly according to the present invention comprises: a housing mounted in an exhaustion system of an engine assembly, and formed with a suction port, a discharge port, and a flow path connecting the suction port and the discharge port; a rod shaped pintle portion provided with an opening and closing member for opening and closing the suction port or the discharge port; an actuator portion mounted on the top of the housing and driving the pintle portion to be lifted for opening and closing operation of the suction port or the discharge port; a bushing portion mounted in the housing and formed with a guide hole guiding lifting movement of the pintle portion; and a shield portion installed between the housing and the actuator portion, blocking penetration of foreign substances from the outside, and formed with a discharge path for discharging exhaust gas at the inside to the outside.

Description

Exhaust gas recirculation valve assembly < RTI ID = 0.0 >

The present invention relates to an EGR valve assembly, and more particularly, to an EGR valve assembly for regulating the amount of exhaust gas recirculated on a recirculation path for recirculating exhaust gas to the engine intake side for reducing nitrogen oxides (NOx).

Nitrogen oxides (NOx) are generated by the combination of oxygen and nitrogen at high pressure and high temperature. In order to suppress this, a part of the exhaust gas discharged into the atmosphere is supplied again to the intake system side to lower the maximum combustion temperature, A technique for reducing the production of oxides is generally referred to as an exhaust gas recirculation (EGR) system.

The amount of exhaust gas returned to the intake side through the EGR system determines the combustion state of the fuel and has a very important influence on the emission of nitrogen oxides (NOx) and particulate matter (PM). Therefore, in an exhaust gas recirculation (EGR) system, it is very important to control the amount of exhaust gas returned to the intake side of the engine.

1 is a schematic configuration diagram of a conventional EGR system applied to a vehicle.

1, the EGR system 100 includes an exhaust line 122 through which exhaust gas generated in the engine 110 is exhausted, an intake line 121 that supplies combustion air to the engine 110, an EGR pipe 131 An EGR valve assembly 140 connected to the exhaust gas discharge line 122 via the EGR valve assembly 140 and an EGR cooler 150 installed in the middle of another EGR pipe 131 connecting the intake line 121 and the EGR valve assembly 140 ).

An EGR pipe 131 is connected to the EGR cooler 150. An inlet 151 through which the cooling water of the engine flows is formed at one side of the EGR pipe 131 and an inlet 151 is formed at the other side of the EGR cooler 150 through the EGR cooler 150, And an outlet 152 through which the cooling water is discharged is formed. The EGR valve assembly 140 is operated by an electric signal transmitted from a control unit (ECU) to regulate the amount of exhaust gas recirculated to the intake side.

When the EGR valve assembly 110 is operated on the open side in response to an instruction from the control unit, the EGR system 100 may be configured such that some of the exhaust gas flowing through the exhaust line 122 flows through the EGR pipe 131 to the suction line 121, And is supplied to the combustion chamber of the engine 110 together with the intake air. At this time, the exhaust gas passing through the EGR pipe 131 is cooled to a predetermined temperature by the EGR cooler 150.

FIG. 2 is a schematic cross-sectional view of a conventional EGR valve assembly applied to an EGR system, and FIG. 3 is an enlarged view of the essential part of FIG.

2 and 3, the exhaust gas flowing into the inlet 142 of the EGR valve housing 141 is discharged to the outlet 143 and circulated to the intake side. A portion 147 of the exhaust gas flows through the gap portion G between the pin frame portion 144 and the guide hole 146 of the bushing portion 145 and the actuator portion The driving unit 147).

The exhaust gas flowing into the housing 141 must be discharged to the outside before being moved to the actuator unit 147 to prevent damage to the actuator unit and the sensor unit 148 above the actuator unit. To this end, there is an air gap 149 between the housing 141 and the actuator part 147 so that the exhaust gas is discharged to the outside before the exhaust gas moves to the actuator part 147.

However, not only the exhaust gas is exhausted to the outside through the air gap 149, but also the foreign material (corrosive fluid, water, etc.) flows from the outside to the inside of the EGR valve assembly through the air gap 149 There arises a problem that the components constituting the actuator unit 147 and the sensor unit 148 are corroded, thereby causing a problem of malfunction or malfunction.

Korean Patent Laid-Open Publication No. 2013-0021216 (published on March 3, 2013)

SUMMARY OF THE INVENTION An object of the present invention is to provide an EGR valve assembly having an improved structure for preventing inflow of corrosive fluid from the outside and exhausting exhaust gas from the outside.

According to an aspect of the present invention as a means for solving the problems,

An EGR valve assembly applied to an EGR system for reducing nitrogen oxides (NOx)

A housing mounted in an exhaust system of the engine assembly, the housing having a suction port and a discharge port, and a flow passage connecting the suction port and the discharge port;

A rod-shaped pin-pin portion having an opening / closing member for opening / closing the suction port or the discharge port at one end;

An actuator mounted on the housing for driving the pintle to lift and lower the inlet or the outlet;

A bushing portion mounted on the housing and having a guide hole for guiding the pintle portion up and down; And

And a shielding portion which is provided between the housing and the actuator and is provided with a discharge passage for preventing infiltration of foreign matter from the outside and discharging the exhaust gas to the outside,

The shield portion

A top shield member of a tubular structure fixed to the bottom surface of the actuator unit so as to surround a part of the pin frame part and having a lower end spaced apart from an upper surface of the housing by a predetermined distance;

And a lower shield member of a tubular structure mounted on the upper surface of the housing, the upper end of which is spaced apart from the lower surface of the actuator by a certain distance, and the upper part of the upper shield member overlaps with the upper shield member to form the discharge passage therebetween And an EGR valve assembly.

Here, the shield member may be fixed to the lower surface of the actuator by being elastically contacted by a coil spring having any elasticity provided between the upper shield member and the bushing member.

In addition, a portion of the lower shield member may be firmly coupled to the housing through the bushing portion mounted on the housing.

The upper shield member may surround a part of the upper end surface of the lower shield member with a certain space therebetween, and the discharge passage may be formed therebetween.

In this case, if the side portion of the upper shield member surrounding a part of the upper end outer surface of the lower shield member is widened radially outward at an arbitrary angle so that the passage area of the exhaust passage becomes wider toward the exit side, So that it can escape more quickly and smoothly.

The upper shield member may further include a seal pin located on the inner side of the lower shield member. In this case, since the discharge passage is formed in a labyrinth shape by the seal pin, foreign substances or moisture It can be prevented more surely.

Preferably, the lower end of the upper shield member surrounding the lower shield member is bent into the shield portion, and the upper end of the lower shield member is bent outwardly of the shield portion so that the discharge passage is formed in a labyrinth shape As shown in FIG.

As another example, a part of the lower end outer surface of the upper shield member may be configured such that the lower shield member surrounds the lower shield member at a certain distance and the discharge passage is formed therebetween.

In this case, the side portion of the lower shield member surrounding a portion of the lower end outer surface of the upper shield member may be extended radially outward at an arbitrary angle so that the passage area of the discharge passage widens toward the outlet side.

Alternatively, the upper shield member may further include a filament formed in the lower shield member and located inside the upper shield member, and the discharge path may be formed in a labyrinth shape in the height direction of the shield by the filament.

According to an aspect of the present invention as a means for solving the problems,

There is provided an EGR system for nitrogen oxide (NOx) reduction comprising the above-described EGR valve assembly.

The EGR valve assembly according to the present invention includes a shield part structured to prevent the inflow of corrosive fluid from the outside and exhaust the exhaust gas inside. Accordingly, corrosion of the actuator unit and the sensor unit due to inflow of the internal exhaust gas into the sensor unit side or penetration of the corrosive fluid outside can be effectively prevented.

1 is a schematic configuration view of a conventional EGR system applied to a vehicle.
2 is a schematic cross-sectional view of a conventional conventional EGR valve assembly applied to an EGR system;
3 is a partial enlarged view of Fig.
4 is a cross-sectional view of an EGR valve assembly according to an embodiment of the present invention.
5 is a cross-sectional view of the bushing portion shown in Fig.
6 is an enlarged view of a main part of an EGR valve assembly according to another embodiment of the present invention.
7 is a view showing a preferred modification of the shield portion shown in Fig.
8 is an enlarged view of a main part of an EGR valve assembly according to another embodiment of the present invention.
9 is a view showing a preferable modification of the shield portion shown in Fig.

Hereinafter, the terminology used in the specification is used only to describe a specific embodiment and is not intended to limit the present invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. It is to be understood that the terms "comprises", "having", and the like in the specification are intended to specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.

Also, the terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

In addition, the terms " part, "" unit," " module, "and the like, which are described in the specification, refer to a unit for processing at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software .

In the following description with reference to the accompanying drawings, the same reference numerals are given to the same constituent elements, and a duplicate description thereof will be omitted. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

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

4 is a cross-sectional view of an EGR valve assembly according to an embodiment of the present invention.

Referring to FIG. 4, the EGR valve assembly according to the embodiment of the present invention mainly comprises a housing 20 and an actuator unit 10 on the upper portion of the housing 20. An exhaust gas flow passage 23 is formed in the housing 20 to connect the suction port 22 to the exhaust port 24 and the exhaust port 24 to connect the suction port 22 and the exhaust port 24. The actuator portion may be configured to be of a negative pressure type or an electric type.

Hereinafter, a solenoid type electric actuator will be described as an example.

Referring again to FIG. 4, the actuator section 10 includes an armature 13 that moves up and down through interaction with the coils 12 and the coils 12. The coil 12 is wound on the bobbin 15 protected by the actuator body 11 in a predetermined pattern and the armature 13 is wound around the bobbin 15 by the electric field generated when a current flows through the coil 12, (15).

At the center of the armature 13, a bar-shaped pin-fulcrum portion 14 which moves up and down together with the armature 13 is engaged. One side of the pin fence 14 is coupled to the armature 13 in the center so that the other side of the pin fence 14 extends toward the housing 20. 4 shows a configuration in which the pintle portion 14 and the suction port 22 are located on the same line so that the pintle portion controls the opening and closing of the suction port.

The pin frame portion 14 extending toward the suction port 22 side of the housing 20 integrally includes an opening and closing member 15 (valve plug) for opening and closing the suction port 22 Respectively. At this time, the opening and closing member 15 is brought into close contact with the valve seat (not shown) on the suction port 22 in accordance with the ascending and descending movement of the pin frame portion 14, or is separated from the valve seat to open and close the suction port 24.

The housing 20 is provided with a bushing portion 17 formed with a guide hole 170 for guiding the lifting and lowering of the pin frame portion 14 in a stable manner. A position sensor 19 for detecting the axial position of the armature 13 and providing a signal for feedback control to the control unit is provided on the actuator unit 10. Here, the position sensor 19 may be electrically connected to the coil 12 through a terminal terminal.

A shield portion 30 is provided between the housing 20 and the actuator portion 10. At this time, the shield portion 30 forms a discharge passage 35 for preventing foreign matter from penetrating from the outside and discharging the exhaust gas from the outside smoothly to the outside. The shield portion 30 applied to the present invention mainly includes an upper shield member 32 installed on the actuator unit 10 and a lower shield member 32 mounted on the housing 20 corresponding to the upper shield member 32. [ (34).

FIG. 5 is an enlarged view of a main part showing an essential part of the present invention, and is an enlarged view of a preferred embodiment of a shield part between the housing and the actuator part.

5, the upper shield member 32 is tightly fixed to the lower surface of the actuator unit 10 so as to surround a part of the pin frame unit 14. As shown in FIG. The coil spring 37 having an elasticity provided between the upper shield member 32 and the bushing 17 as shown in the figure may be used to prevent the shield member 30 from contacting the actuator 10 And can be fixed to the lower surface in a state of being elastically contacted.

The upper shield member 32 may be formed in a cylindrical shape, preferably a cylindrical shape, the lower end of which is spaced apart from the upper surface of the housing 20 by a certain distance and the lower portion thereof is opened. The upper shield member 32 may be made of a synthetic resin or a corrosion resistant metal having high heat resistance and a through hole 320 is formed at the center of the upper surface of the upper shield member 32 so as not to interfere with lifting and lowering of the pin frame 14 .

The lower shield member 34 is mounted and fixed on the upper surface of the housing 20. Preferably, the lower portion of the housing 20 is fixed between the housing 20 and the bushing 17 as shown in FIG. A portion of the lower shielding member 34 may be fixedly coupled to the housing 20 through a bushing 17 mounted on the housing 20.

The lower shield member 34 may be formed in a cylindrical shape, preferably a cylindrical shape, the top of which is opened so that its upper end is located at a height spaced apart from the lower surface of the actuator unit 10 by a certain distance. At this time, as shown in the example of FIG. 5, a part of the upper shield member 32 is overlapped with the axial direction of the fin portion 14 so that the discharge passage 35 may be formed between the upper shield member 32 and the upper shield member 32 .

The shield portion 30 according to one embodiment may be a structure in which a portion of the upper end surface of the lower shield member 34 is surrounded by the upper shield member 32 at an arbitrary interval, as shown in FIG. In this case, the discharge passage 35 may be formed in a vertical direction (vertical direction in the figure) in a section D where a part of the lower shielding member 34 overlaps with a part of the upper shielding member 32.

According to one embodiment of the present invention, the exhaust gas introduced into the shielding portion 30 through the above-described gap (see FIG. 3 related to the related art) when the valve is opened is separated from the upper shielding member 32, Can be smoothly discharged to the outside through the discharge passage (35) between the discharge port (34). Particularly, the lower shield member 34 can prevent the external corrosive fluid from entering the inside of the shield portion 30 by riding on the upper surface of the housing 20.

Fig. 6 is an enlarged view of a main part showing another preferred embodiment of the shield portion. Fig.

6, the side of the upper shield member 32 surrounding a part of the upper end surface of the lower shield member 34 is opened at an arbitrary angle? Radially outwardly, The exhaust gas inside the shield portion 30 can smoothly and smoothly escape to the outside without congestion if the area is enlarged toward the outlet side.

FIG. 7 is an enlarged view showing another preferred embodiment of the shielding portion. The shielding portion 30 includes a sheath 33 formed in the upper shielding member 32 and positioned inside the lower shielding member 34 . In this case, the discharge passage 35 is formed in the shape of a labyrinth continuously bent downward and upward by the seal pin 33, so that the inflow of the corrosive fluid from the outside can be blocked more reliably.

8, which shows another preferred embodiment of the shield 30, the lower end of the upper shield member 32 surrounding the lower shield member 34 is bent inside the shield 30, The upper end of the shielding member 34 may be configured to be bent outwardly of the shielding portion 30 so that the discharge passage 35 is formed in a labyrinth shape in the radial direction of the shielding portion 30. [

9 to 11 are views illustrating various other embodiments of the shield portion.

9, a portion of the lower end of the lower end of the upper shield member 32 may be surrounded by the lower shield member 34 at a certain distance, as opposed to the embodiment of FIG. 5, so that the outer lower shield member 34 The discharge passage 35 may be formed in the vertical direction (the vertical direction in the figure) in a section D where a part of the inner upper shield member 32 overlaps with a part of the inner upper shield member 32.

In the case of the structure in which the lower shielding member 34 surrounds the upper shielding member 32, the lower shielding member 32 surrounding the lower end portion of the upper end shielding member 32, as in the above- The passage area of the discharge passage 35 may be widened toward the outlet side (see FIG. 10) by configuring the discharge passage 35 to be inclined at an arbitrary angle (?) Such that the side of the discharge passage 35 spreads radially outward.

The upper shield member 32 and the upper shield member 32 may be formed in a structure in which the lower shield member 34 surrounds the upper shield member 32 or alternatively may be formed in the lower shield member 34, And the discharge passage 35 is continuously bent upward and downward with respect to the height direction of the shielding portion 30 by the seal pin 33 to form a labyrinth .

In the foregoing detailed description of the present invention, only specific embodiments thereof have been described. It is to be understood, however, that the invention is not to be limited to the specific forms thereof, which are to be considered as being limited to the specific embodiments, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. .

10: Actuator part 11: Actuator body
12: Coil 13: Amateur
14: pin frame portion 15: opening / closing member
17: bushing 19: position sensor
20: housing 22: inlet
24: exhaust port 30: shield part
32: upper shield member 33: seal pin
34: lower shield member 35: exhaust passage

Claims (11)

An EGR valve assembly applied to an EGR system for reducing nitrogen oxides (NOx)
A housing mounted in an exhaust system of the engine assembly, the housing having a suction port and a discharge port, and a flow passage connecting the suction port and the discharge port;
A rod-shaped pin-pin portion having an opening / closing member for opening / closing the suction port or the discharge port at one end;
An actuator mounted on the housing for driving the pintle to lift and lower the inlet or the outlet;
A bushing portion mounted on the housing and having a guide hole for guiding the pintle portion up and down; And
And a shielding portion which is provided between the housing and the actuator and is provided with a discharge passage for preventing infiltration of foreign matter from the outside and discharging the exhaust gas to the outside,
The shield portion
A top shield member of a tubular structure fixed to the bottom surface of the actuator unit so as to surround a part of the pin frame part and having a lower end spaced apart from an upper surface of the housing by a predetermined distance;
And a lower shield member of a tubular structure mounted on the upper surface of the housing, the upper end of which is spaced apart from the lower surface of the actuator by a certain distance, and the upper part of the upper shield member overlaps with the upper shield member to form the discharge passage therebetween Characterized by an EGR valve assembly.
The method according to claim 1,
Wherein the shield member is elastically brought into close contact with the lower surface of the actuator by a coil spring having an elasticity and provided between the upper shield member and the bushing member.
The method according to claim 1,
Wherein the lower shield member is coupled to the housing through a bushing portion mounted on the housing.
The method according to claim 1,
Wherein the upper shield member surrounds a part of an upper end outer surface of the lower shield member at an arbitrary interval, and the discharge passage is formed therebetween.
5. The method of claim 4,
Wherein a side portion of the upper shield member surrounding a part of an upper end outer surface of the lower shield member is extended radially outward at an arbitrary angle so that the passage area of the discharge passage widens toward the outlet side.
5. The method of claim 4,
Further comprising: a seal pin formed in the upper shield member and positioned inside the lower shield member, wherein the discharge passage is formed in a labyrinth shape by the seal pin.
5. The method of claim 4,
Wherein an upper end portion of the upper shield member surrounding the lower shield member is bent toward the inside of the shield portion and an upper end of the lower shield member is bent to the outside of the shield portion so that the discharge passage is formed in a labyrinth shape.
The method according to claim 1,
Wherein the lower shield member surrounds a part of the lower end outer surface of the upper shield member at an arbitrary interval, and the discharge passage is formed therebetween.
9. The method of claim 8,
Wherein a side portion of a lower shield member surrounding a portion of a lower end outer surface of the upper shield member is extended radially outward at an arbitrary angle so that a passage area of the discharge passage widens toward an outlet side.
9. The method of claim 8,
Further comprising: a seal pin formed on the lower shield member and positioned inside the upper shield member, wherein the discharge passage is formed in a labyrinth shape by the seal pin.
An EGR system for nitrogen oxide (NOx) reduction, comprising an EGR valve assembly as claimed in any one of claims 1 to 10.

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