KR20170000799A - Low pressure egr device - Google Patents

Abstract

A valve housing (11) of a low pressure EGR device (1) has a valve chamber (110) accommodating a valve body (10) and a concave seal surface (113) sliding and coming in contact with a convex seal surface (103) of the valve body (10). An EGR duct (12) and an air duct (13) guide EGR gas and intake air, respectively. At least one among the EGR gas and the intake air is discharged from the valve chamber (110) through a mixing duct (14). In an angle range from a complete closing rotation position (P1) of the valve body (1) where the valve body (10) completely closes the EGR duct (12) to an intermediate rotation position of the valve body (10) where the valve body (10) partially opens the EGR duct (12), the valve body (10) completely opens the air duct (13) from a virtual air area connecting a gap between an inlet (130) of the air duct (13) and an outlet (140) of the mixing duct (14).

Description

[0001] LOW PRESSURE EGR DEVICE [0002]

The present invention relates to a low-pressure exhaust gas recirculation (EGR) apparatus applied to an internal combustion engine equipped with a turbocharger.

Generally, in an internal combustion engine equipped with a turbocharger, a turbine of a turbocharger is installed in an exhaust passage, and a compressor of a turbocharger is installed in an intake passage. The turbine is rotated by the internal energy of the exhaust gas discharged from the cylinder into the exhaust passage, and the compressor is rotated by the turbine to compress the intake air (also referred to as intake gas) guided through the intake passage. By doing so, the compressed suction air is supplied to each cylinder of the internal combustion engine, so that the thermal efficiency of the internal combustion engine becomes high. Therefore, the engine output per unit displacement of the internal combustion engine is effectively increased.

Recently, a low pressure EGR apparatus is provided in an internal combustion engine equipped with a turbocharger. The low pressure EGR apparatus is a device for recirculating a part of the exhaust gas to a flow merging section located on the upstream side of the in-intake path compressor from the flow branching section located on the downstream side of the turbine of the exhaust passage to mix the portion of the exhaust gas with the intake gas . As a result, a part of the exhaust gas can be supplied to the cylinder as the EGR gas mixed with the intake gas without reducing the energy of the exhaust gas given to the turbine. Therefore, generation of NOx and generation of pumping loss can be suppressed while increasing turbo efficiency.

In the case of the above-described low pressure EGR apparatus, the EGR gas is recycled from the flow branching portion having a low exhaust pressure to the flow merging portion having a low intake pressure. By doing so, the recirculation flow rate of the EGR gas can be limited to only a small flow rate. In consideration of the above points, the low pressure EGR apparatus of JP2012-237306A (corresponding to US2012 / 0272646A1) has a flow merging section in which EGR gas is supplied from an EGR duct having an EGR valve rotatably installed in the EGR duct, . Thus, from the fully closed rotational position of the EGR valve that completely closes the EGR duct to the predetermined intermediate rotational position of the EGR valve that partly opens the EGR duct, the suction air throttle valve is moved over the entire rotational angle range of the EGR valve, Make the passage fully open. Therefore, in a state in which the pressure loss of the intake air is minimized, the recirculation flow rate of the EGR gas is zero or the minimum necessary flow rate is reduced. On the other hand, the suction air throttle valve restricts the intake passage from the fully opened rotational position of the EGR valve that completely opens the EGR duct to the above-described intermediate rotational position where the EGR duct is partly opened, (For example, the intake air throttle valve reduces the opening degree of the intake passage). Therefore, the intake negative pressure increases and the recirculation flow rate of the EGR gas increases.

However, in the low pressure EGR apparatus of JP2012-237306A (corresponding to US2012 / 0272646A1), the operation of the intake air throttle valve differs for each angular range of the EGR valve. Therefore, the EGR valve and the intake air throttle valve are coupled to each other through the cam mechanism. As a result, the number of parts increases. As a result, the structure of the low-pressure EGR apparatus can be unfavorably complicated, and the size of the low-pressure EGR apparatus can be disadvantageously increased.

In addition, in the low pressure EGR apparatus of JP2012-237306A (corresponding to US2012 / 0272646A1), the intake air throttle valve is provided in the flow merging section constituting a part of the intake passage. Therefore, even when the suction air throttle valve is fully opened, the flow of the suction air is interrupted. As a result, the engine efficiency of the internal combustion engine deteriorates. Therefore, improvement is required to satisfy the required characteristics of the low-pressure EGR apparatus.

The present invention has been made in view of the above points. It is therefore an object of the present invention to provide a low-pressure EGR apparatus which can simplify the structure of the low-pressure EGR apparatus, reduce the size of the low-pressure EGR apparatus, and satisfy the required characteristics.

According to the present invention, the EGR gas is recirculated from the flow branching portion of the exhaust passage located on the downstream side of the turbine of the turbocharger provided in the internal combustion engine to the flow merging portion of the intake passage located on the upstream side of the compressor of the turbocharger , And a low-pressure EGR apparatus for mixing the EGR gas with the intake air guided in the intake passage is provided. The low pressure EGR apparatus includes a valve body, a valve housing, an EGR duct, an air duct, and a mixing duct. The valve body has a convex seal face that is partially spherical in shape. The valve body is rotatable about a rotational axis extending through the center of curvature of the convex seal surface. The valve housing has a valve chamber and a concave sealing surface. The valve chamber forms a flow merging portion and receives the valve body. The concave sealing surface is in the form of a partial spherical surface and is exposed to the valve chamber. The concave sealing surface is in sliding contact with the convex sealing surface. The EGR duct guides the EGR gas supplied from the flow branching portion to the valve chamber. The air duct forms a passage portion of the intake passage located on the upstream side of the flow merging portion. The air duct guides the suction air to the valve chamber. The mixing duct forms a passage portion of the intake passage located on the downstream side of the flow merging portion. At least one of the EGR gas and the intake air flows out from the valve chamber through the mixing duct. The concave sealing surface is located between the EGR duct and the air duct. And is formed as a virtual region connecting the inlet of the air duct into which the intake air flows into the valve chamber and the outlet of the mixing duct in which at least one of the EGR gas and the intake air flows out to the valve chamber, . The valve body is displaced from the virtual air region and is moved from the fully closed rotational position of the valve body that completely closes the EGR duct to the predetermined intermediate rotational position of the valve body that partially opens the EGR duct, Open the duct completely.

The following drawings are for illustrative purposes only and are not intended to limit the scope of the invention.
1 is a schematic view showing a structure of a system in which a low-pressure EGR apparatus according to a first embodiment of the present invention is applied to an internal combustion engine for a vehicle equipped with a turbocharger.
2 is a cross-sectional view of the low-pressure EGR apparatus according to the first embodiment taken along line II-II in Fig.
3 is a front view of the low-pressure EGR apparatus according to the first embodiment taken along the line III-III in FIG.
4 is a side view of the low-pressure EGR apparatus according to the first embodiment taken along the line IV-IV in Fig.
5A to 5C are schematic diagrams showing one operating state of the low-pressure EGR apparatus according to the first embodiment and corresponding to FIGS. 2 to 4, respectively.
Figs. 6A to 6C show another operating state of the low-pressure EGR apparatus according to the first embodiment, and are schematic views respectively corresponding to Figs. 2 to 4. Fig.
Figs. 7A to 7C show another operating state of the low-pressure EGR apparatus according to the first embodiment, and are schematic views respectively corresponding to Figs. 2 to 4. Fig.
Figs. 8A to 8C are schematic views corresponding to Figs. 2 to 4 respectively showing still another operating state of the low-pressure EGR apparatus according to the first embodiment. Fig.
Figs. 9A to 9C show another operating state of the low-pressure EGR apparatus according to the first embodiment, and are schematic views corresponding to Figs. 2 to 4, respectively.
10 is a graph showing the characteristics of the low-pressure EGR apparatus according to the first embodiment.
Fig. 11 is a cross-sectional view taken along the line XI-XI in Fig. 12, showing a cross-section of the low-pressure EGR apparatus according to the second embodiment of the present invention.
12 is a front view showing the low-pressure EGR apparatus according to the second embodiment taken along the line XII-XII in FIG.
13 is a side view showing the low-pressure EGR apparatus according to the second embodiment taken along line XIII-XIII in Fig.
Figs. 14A to 14C are schematic views corresponding to Figs. 11 to 13 showing one operating state of the low-pressure EGR apparatus according to the second embodiment. Fig.
Figs. 15A to 15C are schematic views corresponding to Figs. 11 to 13 showing another operating state of the low-pressure EGR apparatus according to the second embodiment. Fig.
Figs. 16A to 16C are schematic views corresponding to Figs. 11 to 13 showing another operating state of the low-pressure EGR apparatus according to the second embodiment. Fig.
17 is a cross-sectional view taken along the line XVII-XVII in Fig. 18, showing a cross section of the low-pressure EGR apparatus according to the third embodiment of the present invention.
18 is a front view of the low-pressure EGR apparatus according to the third embodiment taken along the line XVIII-XVIII in Fig.
19 is a side view of the low-pressure EGR apparatus according to the third embodiment taken along the line XIX-XIX in Fig.
20A to 20C are schematic views corresponding to Figs. 17 to 19, respectively, showing one operating state of the low-pressure EGR apparatus according to the third embodiment.
Figs. 21A to 21C are schematic views corresponding to Figs. 17 to 19, respectively, showing still another operating state of the low-pressure EGR apparatus according to the third embodiment.
22A to 22C are schematic views corresponding to FIGS. 17 to 19, respectively, showing still another operating state of the low-pressure EGR apparatus according to the third embodiment.
FIG. 23 is a cross-sectional view taken along line XXIII-XXIII of FIG. 24, showing a cross-section of the low-pressure EGR apparatus according to the fourth embodiment of the present invention.
24 is a front view of the low-pressure EGR apparatus according to the fourth embodiment taken along the line XXIV-XXIV in Fig.
25 is a side view of the low-pressure EGR apparatus according to the fourth embodiment taken along line XXV-XXV in Fig.
26A to 26C are schematic views corresponding to FIGS. 23 to 25, respectively, showing one operating state of the low-pressure EGR apparatus according to the fourth embodiment.
27A to 27C are schematic views corresponding to FIGS. 23 to 25, respectively, showing still another operating state of the low-pressure EGR apparatus according to the fourth embodiment.
28A to 28C are schematic views corresponding to FIGS. 23 to 25, respectively, showing still another operating state of the low-pressure EGR apparatus according to the fourth embodiment.
29 is a cross-sectional view taken along the line XXIX-XXIX of Fig. 30 showing the low-pressure EGR apparatus according to the fifth embodiment of the present invention.
Fig. 30 is a front view of the low-pressure EGR apparatus according to the fifth embodiment taken along the line XXX-XXX in Fig.
31 is a side view of the low-pressure EGR apparatus according to the fifth embodiment taken along the line XXXI-XXXI in FIG.
32A to 32C are schematic views corresponding to FIGS. 29 to 31, respectively, showing one operating state of the low-pressure EGR apparatus according to the fifth embodiment.
33A to 33C show still another operating state of the low-pressure EGR apparatus according to the fifth embodiment, and are schematic views respectively corresponding to Figs. 29 to 31. Fig.
FIGS. 34A to 34C are schematic views corresponding to FIGS. 29 to 31, respectively, showing still another operating state of the low-pressure EGR apparatus according to the fifth embodiment.
35 is a sectional view showing a modification of Fig.
Fig. 36 is a sectional view showing a modification of Figs. 11 and 17. Fig.
37 is a sectional view showing a modification of Figs. 23 and 29. Fig.

Various embodiments of the present invention will be described with reference to the accompanying drawings. In the following embodiments, similar components will be denoted by the same reference numerals, and may not be redundantly described for the sake of clarity. Hereinafter, in each embodiment, when only a part of the structure is described, the remaining part of the structure is the same as the structure of the embodiment (s) explained earlier. Furthermore, unless explicitly described in the following description, components of one or more of the following embodiments may be used in combination with one or more other implementations, as well as combinations of components explicitly described in the embodiments, Can be partially combined with the elements of the form.

(First Embodiment)

1, a low-pressure EGR device (also referred to as a low-pressure loop EGR device) 1 is provided in an internal combustion engine 3 for a vehicle (e.g., a motor vehicle) equipped with a turbocharger 2 do.

In the present embodiment, the internal combustion engine 3 is a diesel engine, and burns diesel fuel (serving as fuel of the present invention) in the cylinder 30. The internal combustion engine 3 has an intake passage 31 for supplying intake air (also referred to herein as intake gas) to the cylinder 30. The internal combustion engine 3 also has an exhaust passage 32 for exhausting the exhaust gas generated by the combustion in each cylinder 30 to the outside. The internal combustion engine 3 also has an EGR passage 33 for recirculating a part of the exhaust gas discharged from the exhaust passage 32 (serving as the EGR gas) to the intake passage 31.

An air cleaner 34, an intercooler 35, and a throttle valve 36 are provided in the intake passage 31. The air cleaner 34 collects solid particulate matter (foreign matter) such as dust contained in the air introduced from the outside. The intercooler 35 is compressed by the compressor 21 of the turbocharger 2 to expand the intake air having a high temperature, thereby cooling the intake air. The throttle valve 36 is driven to regulate the valve opening degree to regulate the amount of intake air supplied to each corresponding cylinder 30.

An exhaust treatment device 37 is provided in the exhaust passage 32. The exhaust treatment device 37 purifies the exhaust gas discharged into the exhaust passage 32. Here, it should be noted that a diesel particulate filter (DPF) may be employed as the exhaust treatment device 37 for trapping the particulate matter contained in the exhaust gas. Alternatively or additionally, a selective catalytic reduction (SCR) device, an LNT (Lean NOx Trap) device, and / or an NSR (NOx Storage Reduction) device may be used as an exhaust treatment device 37 for reducing NOx contained in exhaust gas .

The EGR passage 33 communicates between the exhaust passage 32 and the intake passage 31. Specifically, the EGR passage 33 communicates with the flow branching portion 320 formed in the exhaust passage 32 at a position on the downstream side of the turbine 20 and the exhaust treatment device 37 of the turbocharger 2. The EGR passage 33 communicates with the flow merging portion 310 formed in the intake passage 31 at the downstream side of the air cleaner 34 and the upstream side of the compressor 21. With the above-described structure, the EGR passage 33 recirculates the EGR gas, which is a part of the exhaust gas, from the flow branching portion 320 having a low exhaust pressure to the flow merging portion 310 having a low intake negative pressure, Mix with suction air.

An EGR cooler 38 is installed in the EGR passage 33. The EGR cooler 38 cools the EGR gas sucked into the cylinder 30 when recirculating the EGR gas to the intake passage 31, thereby suppressing the generation of NOx.

The turbocharger (2) has at least one set of turbine (20) and a compressor (21). The turbine 20 is installed in the exhaust passage 32 at a position on the upstream side of the exhaust treatment device 37 and the flow branching portion 320. The compressor 21 is installed in the intake passage 31 at a position downstream of the flow merging section 310 and at a position upstream of the throttle valve 36 and the intercooler 35. The turbine 20 drives the compressor 21 connected coaxially with the turbine 20 by rotating by the internal energy of the exhaust gas discharged into the exhaust passage 32. [ As a result, the suction air is compressed and supercharged to each cylinder 30. The turbocharger 2 of the present invention may be a single turbocharger as shown in FIG. 1 or may be a twin-scroll turbocharger, a variable capacity turbocharger, a parallel twin-turbocharger, a sequential turbocharger, It should be noted that it may be another type of turbocharger, such as a supercharger.

The low pressure EGR device 1 is formed in the flow merging portion 310 and the passage portions 311 and 312 of the intake passage 31 and the passage portion 330 of the EGR passage 33. The passage portions 311 and 312 are located on both sides (the upstream side and the downstream side) of the flow merging portion 310 of the intake passage 31, respectively. The passage portion 330 extends toward the flow merging portion 310 of the EGR passage 33. 2 to 4, the low pressure EGR apparatus 1 includes a valve body 10, a valve housing 11, an EGR duct 12, an air duct 13, a mixing duct 14, and an electric actuator (15). In order to facilitate the understanding of the explanation, in Figs. 2 to 4 and Figs. 5 to 9, the X direction, Y direction and Z direction are defined in an orthogonal coordinate system (three-dimensional coordinate system).

 The valve body 10 is a ball valve made of metal. The valve body (10) includes a seat portion (100), a plurality of arm portions (101), and a valve shaft portion (102). The seat portion 100 has a partially spherical shape. Thereby, the outer surface of the sheet portion 100 forms a convex sealing surface 103 which is partially spherical in shape. The seat portion 100 is provided with a rotation shaft (not shown) extending in the Z direction through the center of curvature Cv of the convex sealing surface 103 (e.g., the center of a virtual sphere having an outer surface on which the convex sealing surface 103 is formed) Lv.

The arm portion 101 is rotatable integrally with the seat portion 100, and the number of the arm portions 101 is two in this case. The arm portions 101 are substantially perpendicular to the rotation axis Lv and are substantially parallel to each other. Each of the arm portions 101 has a flat plate shape having a fan shape. The arm portion 101 extends from the two edges of the seat portion 100 facing each other in the Z direction extending along the rotation axis Lv toward the rotation axis Lv in the radial direction of the rotation axis Lv Lv < / RTI > The arm portions 101 are spaced apart from each other in the direction of the rotation axis Lv by a distance larger than the inner diameter of the air duct 13 (more specifically, the inner diameter of the inlet 130 of the air duct 13 is described below) . This distance between the arm portions 101 can alternatively be set to be equal to the inner diameter of the air duct 13 (more specifically, the inner diameter of the inlet 130 of the air duct 13). In some cases, the distance between the arm portions 101 may be set to be smaller than the inner diameter of the air duct 13 (more specifically, the inner diameter of the inlet 130 of the air duct 13), if necessary. The space portion 105 is formed in the valve body 10 so as to extend from the position between the arm portions 101 to the inner peripheral side of the seat portion 100 by the above-described structure.

The valve shaft portion 102 is formed to be rotatable integrally with the seat portion 100 and the arm portion 101. In the present embodiment, the metal member forming the valve shaft portion 102 is fixed to the metal member forming the seat portion 100 and the arm portion 101 so as to be rotatable integrally. The valve shaft portion 102 has a cylindrical shape extending linearly along the rotation axis Lv. The valve shaft portion 102 extends from one of the arm portions 101 toward the other side of the other arm portion 101. [

The valve housing 11 is made of metal and has a corrugated shape. The valve housing 11 has a valve chamber 110 formed in a spherical space. The valve chamber 110 forms the flow merging portion 310 of the intake passage 31. The valve chamber 110 rotatably accommodates the seat portion 100 and the arm portion 101 of the valve body 10. The inner surface of the valve housing 11 forms two planar support surfaces 111 on both sides of the valve body 10 facing each other in the Z direction. The planar support surfaces 111 exposed to the valve chamber 110 are substantially orthogonal to the rotation axis Lv, and are parallel to each other. The flat support surface 111 supports the arm portions 101 in sliding contact with each other when the valve body 10 rotates.

A part of the inner surface of the valve housing 11 located between the planar support surfaces 111 holding the valve body 10 in the Z direction forms a concave sealing surface 113 having a partial spherical shape. The concave sealing surface 113 extends between the EGR duct 12 and the air duct 13 and extends between the EGR duct 12 and the mixing duct 14 and extends between the air duct 13 and the mixing duct 14, / RTI > The concave sealing surface 113 is exposed to the valve chamber 110 and is defined by a center of curvature Ch of the concave sealing surface 113 (e.g., a virtual center of gravity having an outer surface on which the concave sealing surface 113 is formed) Substantially coincides with the center of curvature Cv of the convex sealing surface 103. [ As a result, the concave sealing surface 113 comes into sliding contact with the convex sealing surface 103 when the valve body 10 rotates.

The wall portion of the valve housing 11 forming one of the planar support surfaces 111 forms a bearing portion 112. The valve shaft portion 102 is airtight and extends rotatably through the bearing portion 112. The bearing portion 112 rotatably supports the valve shaft portion 102 extending from the arm portion 101 located in the valve chamber 110 to the outside of the valve housing 11. [

The EGR duct 12 is made of metal and has a cylindrical tubular shape. A passage portion 330 extending toward the flow merging portion 310 is formed inside the EGR duct 12. The EGR duct 12 extends from the valve housing 11 toward the opposite side of the rotation axis Lv in the X direction substantially perpendicular to the rotation axis Lv. The EGR duct 12 has the center axis Le extending through the center of curvature Cv, Ch and being substantially orthogonal to the rotation axis Lv. The radius of the inner peripheral surface of the EGR duct 12 measured from the center axis Le is set to be smaller than the radius of curvature of the concave sealing surface 113 measured from the center of curvature Ch of the concave sealing surface 113. [

The EGR duct 12 has an inlet 120 that forms the most downstream end of the passage portion 330. The inner circumferential surface of the inlet 120 is connected to the concave sealing surface 113 over the entire circumferential range of the inner peripheral surface of the inlet 120 so that the passage portion 330 communicates with the flow merging portion 310. Thereby, the inlet port 120 is connected to the EGR gas supplied from the flow branching section 320 (see Fig. 1) in the rotational positions P2 to P5 of the valve body 10 shown in Figs. 6A to 9C to the valve chamber 110). On the other hand, the inlet port 120 is completely closed at the rotational position P1 of the valve body 10 shown in Figs. 5A to 5C, so that the inflow of the EGR gas into the valve chamber 110 is blocked.

2 and 4, a seal member 113a, which is rubber-like and ring-shaped, is provided in the valve housing 11 so as to be connected to a connecting portion between the inner circumferential surface of the EGR duct 12 and the concave sealing surface 113 Respectively. Thereby, at the rotational position (also referred to herein as the fully closed rotational position) at which the valve body 10 fully closes the inlet 120 of the EGR duct 12, the convex sealing surface 103 And the concave seal surface 113 is hermetically sealed by the seal member 113a.

2 to 4, the air duct 13 is made of metal and has a cylindrical tubular shape. The passage portion 311 located on the upstream side of the flow merging portion 310 is formed inside the air duct 13. The air duct 13 extends from the valve housing 11 toward the opposite side of the rotation axis Lv and the center axis Le in the Y direction which is substantially perpendicular to the rotation axis Lv and the center axis Le. The central axis La of the air duct 13 extends through the centers of curvature Cv and Ch and is substantially orthogonal to the rotation axis Lv. The rotary shaft Lv of the valve body 10 intersects both the center axis Le of the EGR duct 12 and the center axis La of the air duct 13. [ A right angle? Ar is formed between the center axis La of the air duct 13 and the center axis Le of the EGR duct 12 as shown in Fig. The radius of the inner circumferential surface of the air duct 13 measured from the center axis La is set to be smaller than the radius of curvature of the concave sealing surface 113. [

As shown in Figs. 2 to 4, the air duct 13 has an inlet 130 forming the most downstream end of the passage portion 311. The inner circumferential surface of the inlet 130 is connected to the concave sealing surface 113 over the entire circumferential range of the inner circumferential surface of the inlet 130 so that the inlet 130 communicates the passage 311 with the flow merging portion 310, . Thereby, when the inlet 130 is opened at each of the rotational positions P1 to P4 of the valve body 10 shown in Figs. 5A to 8C, the inlet port 130 guides the suction air to the valve chamber 110 do. 9A-9C, the inlet 130 is limited to a maximum by the valve body 10 (e.g., the opening of the inlet 130 is minimized) The flow rate of the suction air to the valve chamber 110 through the inlet 130 is maximally limited (for example, the flow rate of the suction air to the valve chamber 110 is minimized).

2 and 3, the mixing duct 14 is made of metal and has a cylindrical tubular shape. The passage portion 312 located on the downstream side of the flow merging portion 310 is formed inside the mixing duct 14. The mixing duct 14 extends from the valve housing 11 in the Y direction toward the opposite side of the air duct 13, the rotation axis Lv and the center axis Le. The central axis Lm of the mixing duct 14 extends through the centers of curvature Cv and Ch and is substantially orthogonal to the rotational axis Lv. A right angle? Mr is formed between the center axis Lm of the mixing duct 14 and the center axis Le of the EGR duct 12 as shown in Fig. The center axis Lm of the mixing duct 14 and the center axis La of the air duct 13 are not offset with respect to the rotation axis Lv and the center of curvature Ch but overlap each other. That is, the center axis Lm of the mixing duct 14 and the center axis La of the air duct 13 are coaxial with each other. The radius of the inner peripheral surface of the mixing duct 14 measured from the central axis Lm is smaller than the radius of curvature of the concave sealing surface 113. In this embodiment, the radius of the inner peripheral surface of the air duct 13 is substantially Is set to be the same.

The mixing duct (14) has an outlet (140) forming the most upstream end of the passageway (312). The inner circumferential surface of the outlet 140 is connected to the concave sealing surface 113 over the entire circumference of the inner peripheral surface of the outlet 140 so that the outlet 140 allows the passage 312 to flow into the flow merging portion 310, . Thereby, at least one of the EGR gas and the intake air is discharged from the valve chamber 110 through the outlet port 140 in accordance with the rotational position of the valve body 10. Concretely, at the fully closed rotational position P1 of the valve body 10 shown in Figs. 5A to 5C, the inhaled air introduced from the air duct 13 having the inlet 130 opened to the valve chamber 110 Gas flows out of the valve chamber 110 into the mixing duct 14, which has an outlet 140 and is always open. On the other hand, the EGR gas supplied from the EGR duct 12 having the inlet port 120 opened to the valve chamber 110 and the EGR gas supplied from the EGR duct 12, which are opened in the valve chamber 110, The intake gas supplied from the air duct 13 having the inlet 130 opened to the valve chamber 110 is mixed in the valve chamber 110 and this mixture of the EGR gas and the intake gas is supplied from the valve chamber 110 Outlet port 140 and is always flowed out to the open mixing duct 14. [

In this embodiment, a virtual air region Aa is formed in the valve chamber 110 of the valve housing 11, as shown in Figs. 5A to 9C. Specifically, as shown in Figs. 5A, 6A, 7A, 8A, and 9A, a cylindrical tubular shape (cylindrical shape) is formed, and the inner periphery edge of the inlet 130 of the air duct 13 and the inner peripheral edge of the mixing duct 14 The virtual air region Aa is formed as a virtual region connecting the inner peripheral edge of the outlet 140 at the shortest distance. In this case, due to the presence of the space portion 105, from the fully closed rotational position P1 of the valve body 10 shown in Figs. 5A to 5C, the inlet of the EGR duct 12 shown in Figs. 7A to 7C (See Fig. 10) of the valve element 10 to the predetermined intermediate rotational position P3 of the valve element 10 partially opening the valve element 10, Is completely displaced from the virtual air area Aa. As a result, the inlet port 130 is held in a fully opened state by the valve body 10 over the entire rotational angle range Rcm of the valve body 10. [ 9A-9C, in which the flow restriction of the inlet port 130 by the valve body 10 is maximized (for example, the opening of the inlet port 130 is minimized) (Hereinafter also referred to as the maximum limit rotational position P5) in the intermediate rotational position P3 through the intermediate rotational position P4 shown in Fig. 8, and is positioned in front of the intermediate rotational position P4 in the intermediate rotational position P3 (See the rotation position P6 in Fig. 10) to the virtual air area Aa in the rotation angle range Rsm (see Fig. 10). The entire valve element 10 overlaps with the virtual air area Aa at the maximum limit rotational position P5. However, as shown in Fig. 9A, the clearance between the convex sealing face 103 and the concave sealing face 113 . As a result, the inlet 130 is positioned partially open or partially closed by the valve body 10 throughout the rotation angle range Rsm.

Further, in the embodiment of the present invention, as shown in Fig. 9A, the virtual EGR region Ae is formed in the valve chamber 110 of the valve housing 11. Specifically, as shown in Figs. 5A, 6A, 7A, 8A and 9A, a cylindrical tubular shape (cylindrical shape) is formed, and an inner circumferential edge of the inlet port 120 of the EGR duct 12, A virtual EGR region Ae is formed as a virtual region connecting the inner circumferential edge of the outflow opening 140 of the exhaust passage 14 at the shortest distance. In this case, due to the presence of the space portion 105, the rotation position (the rotation position P7 in Fig. 10) located before the maximum limit rotation position P5 from the maximum limit rotation position P5 shown in Figs. 9A to 9C, The valve body 10 is completely displaced from the imaginary EGR region Ae throughout the entire rotational angle range Rss of the valve body 10. [ As a result, the inlet port 120 is held in a fully opened state by the valve body 10 throughout the rotational angle range Rss including the maximum limited rotational position P5. On the other hand, as shown in Figs. 5A to 8C, the valve body 10 overlaps the virtual EGR region Ae in the rotation angle range other than the rotation angle range Rss. As a result, the inlet port 120 is held partially or partially closed by the valve body 10 or fully closed by the valve body 10.

In the present embodiment, the metal member forming half of each of the valve housing 11 and the ducts 12 to 14 is a metal member that forms the other half of each of the valve housing 11 and the ducts 12 to 14, The valve body 10 is fixed in a state interposed therebetween in the Z direction. The metal members are bonded to each other at the interface between these metal members which are fixed to each other, as shown in Figs. 3, 4, 5B, 5C, 6B, 6C, 7B, 7C, 8B, 8C, 9B, Are omitted for clarity.

As shown in Figs. 3 and 4, the electric actuator 15 is formed by combining a reduction mechanism with, for example, an electric motor. The electric actuator 15 has an output shaft portion (not shown) which is coaxially connected to the valve shaft portion 102 on the outside of the valve housing 11. The electric actuator 15 receives a control command from the engine ECU for controlling the internal combustion engine 3 according to the operating state of the internal combustion engine 3. [ The electric actuator 15 rotates the valve shaft portion 102 by outputting the rotational torque from the output shaft portion according to the control command.

The overall operation of the low-pressure EGR apparatus 1 will be described below. 10, both the flow rate of the suction air when the maximum flow rate Famax of the suction air is set to 100% and the flow rate of the EGR gas when the maximum flow rate Femax of the EGR gas is set to 100% Shown on the vertical axis.

For example, in the case where the internal combustion engine 3 is under a high load operation, in accordance with the control command output from the engine ECU, the electric actuator 15 rotates to the fully closed rotational position P1 shown in Figs. 5A to 5C and 10 The valve body 10 is rotated. Thereby, the EGR duct 12 is completely closed, and the air duct 13 is completely opened. At this time, the flow rate of the suction air flowing out from the air duct 13 through the valve chamber 110 to the mixing duct 14 becomes the maximum flow rate Famax shown in FIG. On the other hand, since the EGR gas does not flow out from the EGR duct 12 to the mixing duct 14 through the valve chamber 110, the flow rate of the EGR gas becomes zero as shown in FIG. As a result, the EGR rate, which is the mixing ratio of the EGR gas to the intake air, is adjusted to zero (zero value).

For example, in the case where the internal combustion engine 3 is operated with a low EGR rate, the electric actuator 15 is operated in accordance with the control command output from the engine ECU, And rotates the valve chamber 110 to the position P2. Thereby, the air duct 13 is kept in the fully opened state, and the EGR duct 12 starts to open. At this time, the flow rate of the suction air flowing out from the air duct 13 through the valve chamber 110 to the mixing duct 14 becomes the maximum flow rate Famax shown in FIG. On the other hand, the flow rate of the EGR gas flowing out from the EGR duct 12 to the mixing duct 14 through the valve chamber 110 is limited to the minimum flow rate (Femin) shown in FIG. As a result, the EGR rate is limited to a low rate close to zero (zero value).

For example, in the case where the internal combustion engine 3 is operated with the EGR rate higher than the above-described low rate, in accordance with the control command output from the engine ECU, the electric actuator 15 is operated as shown in Figs. 7A to 7C and 10 And rotates the valve body 10 to the intermediate rotational position P3. Thus, the EGR duct 12 is maintained at the intermediate rotational position P2 at the opening degree of the EGR duct 12 which is set when the valve element 10 is held at the intermediate rotational position P2 The large open road is partially open. At this time, the flow rate of the suction air flowing out from the air duct 13 through the valve chamber 110 to the mixing duct 14 becomes the maximum flow rate Famax shown in FIG. 10, the flow rate of the EGR gas flowing from the EGR duct 12 to the mixing duct 14 through the valve chamber 110 is smaller than the minimum flow rate Femin, . As a result, the EGR rate is adjusted to a range smaller than the maximum rate.

For example, in a case where the internal combustion engine 3 is operated at a high EGR rate in a state where the exhaust pressure is satisfied, in accordance with the control command outputted from the engine ECU, the electric actuator 15 is shown in Figs. 8A to 8C and 10 And rotates the valve body 10 to the intermediate rotational position P4. Thus, the air duct 13 starts to be closed, and the EGR duct 12 is opened at a part of the open road which is larger than the opening degree of the EGR duct 12 in a state where the valve body 10 is located at the intermediate rotational position P3. do. At this time, the flow rate of the suction air flowing out from the air duct 13 through the valve chamber 110 to the mixing duct 14 is limited to the flow rate Fal smaller than the maximum flow rate Famax shown in Fig. On the other hand, the flow rate of the EGR gas flowing out from the EGR duct 12 through the valve chamber 110 to the mixing duct 14 is substantially equal to the flow rate Feu which is substantially greater than the minimum flow rate Femin do. As a result, the EGR rate is increased to a range smaller than the maximum rate.

For example, in a case where the internal combustion engine 3 is operated at a high EGR rate in a state where the exhaust pressure is insufficient, in accordance with the control command output from the engine ECU, the electric actuator 15 is operated as shown in Figs. 9A to 9C and 10 And rotates the valve body 10 to the maximum limit rotational position P5. Thereby, the restriction of the air duct 13 is maximized (for example, the opening degree of the air duct 13 is minimized) and the EGR duct 12 is fully opened. At this time, the flow rate of the suction air flowing out from the air duct 13 through the valve chamber 110 to the mixing duct 14 is reduced to the minimum flow rate Famin shown in FIG. On the other hand, the flow rate of the EGR gas flowing out from the EGR duct 12 to the mixing duct 14 through the valve chamber 110 is increased to the maximum flow rate Femax shown in FIG. As a result, the EGR rate is adjusted to the maximum rate.

The operation and effect of the first embodiment will be described below.

According to the first embodiment, the concave sealing surface 113 is partially spherical in shape and exposed to the valve chamber 110 accommodating the valve body 10. The concave sealing surface 113 is in sliding contact with the partially spherical convex sealing surface 103 and is formed between the EGR duct 12 of the valve housing 11 and the air duct 13. The valve body 10 commonly used for controlling the opening degree of both the EGR duct 12 and the air duct 13 is formed to have a center of rotation Lv extending through the center of curvature Cv of the convex sealing face 103 The opening degree of the EGR duct 12 and the opening degree of the air duct 13 can be controlled simultaneously at different opening degrees. More specifically, the valve body 10 is configured such that the valve body 10 moves from the fully closed rotational position P1 of the valve body 10 which completely closes the EGR duct 12 to the EGR duct 12, The air duct 13 can be opened in the rotational angle range Rcm of the valve body 10 up to the predetermined intermediate rotational position P3 of the valve body 10 partially opening the valve body 10. [ The valve element 10 is displaced from the virtual air region Aa connecting between the inlet 130 of the air duct 13 and the outlet 140 of the mixing duct 14. The air duct 13 forming the passage portion 311 located on the upstream side of the flow merging portion 310 of the intake passage 31 is maintained in the fully opened state and does not impede the flow of the intake air. Therefore, in a state in which the pressure loss of the intake air is minimized, the recirculation flow rate of the EGR gas is reduced to zero or a necessary minimum flow rate. On the other hand, the valve body 10 has an angular range Rsm from the fully opened rotational position P5 for fully opening the EGR duct 12 to the rotational position located before the intermediate rotational position P3 described above, It is possible to restrict the air duct 13 (i.e., the valve body 10 can reduce the opening of the air duct 13). The air duct 13 is connected to the valve chamber 110 as compared with the EGR duct 12 that smoothly supplies the EGR gas to the valve chamber 110 forming the flow merging portion 310 in the intake passage 31. [ Thereby limiting the flow rate of the suction air supplied to the suction port. Therefore, the intake negative pressure increases, and accordingly, the recirculation flow rate of the EGR gas increases.

According to the first embodiment, the low-pressure EGR device 1 (1) satisfies the required operating characteristics required of the low-pressure EGR device 1 and uses the valve element 10 in common with the EGR duct 12 and the air duct 13 ) And the size of the low-pressure EGR apparatus 1 can be reduced.

According to the first embodiment, when the valve body 10 is located at the maximum restricting rotational position P5 at which the air duct 13 is limited to the maximum, the valve body 10 is closed at the inlet of the EGR duct 12 Is displaced from the virtual EGR region (Ae) connecting between the outlet (120) of the mixing duct (14) and the outlet (140) of the mixing duct (14). Thus, the valve body 10 fully opens the EGR duct 12. Therefore, when the EGR duct 12 is fully opened to increase the recirculating flow rate of the EGR gas, the pressure loss of the EGR gas can be reduced without impeding the flow of the EGR gas. Furthermore, the probability of collision with the hot EGR gas containing steam is reduced with respect to the valve body 10 displaced in the virtual EGR region Ae. Therefore, even when the intake air collides against the valve body 10 held at the maximum limit rotational position P5, the collision of the EGR gas against the valve body 10 can be suppressed and the EGR Condensation of water vapor contained in the gas can be suppressed. In this way, as the condensate reaches the compressor 21 located on the downstream side of the low-pressure EGR apparatus 1 in the intake passage 31, it becomes possible to avoid occurrence of abnormality such as erosion.

(Second Embodiment)

As shown in Figs. 11 to 13, the second embodiment of the present invention is a modification of the first embodiment. The center axis Le of the EGR duct 2012 of the second embodiment is offset from the opposite side of the air duct 13 in the Y direction with respect to the rotation axis Lv and the curvature centers Cv and Ch of the valve body 10 And is set to extend through the position Se. The remaining structure of the EGR duct 2012 other than the above-described points is substantially the same as that of the EGR duct 12 of the first embodiment.

In the second embodiment as well, the full-closed rotation position P1 of the valve body 10 shown in Figs. 14A to 14C is changed to the predetermined intermediate rotation position P3 of the valve body 10 shown in Figs. 15A to 15C The valve element 10 is completely displaced from the virtual air area Aa to maintain the air duct 13 in a fully opened state. Also in the second embodiment, the rotation angle range of the valve body 10 from the maximum limit rotation position P5 shown in Figs. 16A to 16C to the rotation position located before the maximum limit rotation position P5 The valve element 10 is completely displaced from the virtual EGR region Ae to maintain the EGR duct 2012 in a fully opened state.

According to the second embodiment, the EGR duct 2012 includes a central axis Le extending through a position Se offset from the rotation axis Lv of the valve body 10, which is directed to the opposite side of the air duct 13 in the Y- ). Therefore, the EGR duct 2012 is separated from the air duct 13 as much as possible. In other words, compared with the EGR duct 12 of the first embodiment, the EGR duct 2012 is further separated from the air duct 13. [ The rotation angle range Rcm of the valve body 10 from the fully closed rotation position P1 of the valve body 10 to the predetermined intermediate rotation position P3 of the valve body 10 can be increased . Therefore, it is possible to satisfy the required characteristics of reducing the pressure loss of the intake air.

(Third Embodiment)

As shown in Figs. 17 to 19, the third embodiment of the present invention is a modification of the first embodiment. The center axis La of the air duct 3013 of the third embodiment is offset from the center of curvature Cv and Ch and the rotational axis Lv of the valve element 10 toward the opposite side of the EGR duct 12 in the X direction And is set to extend through the position Sa. The center axis Lm of the mixing duct 3014 of the third embodiment is offset from the center of curvature Cv and Ch and the rotational axis Lv of the valve element 10 toward the opposite side of the EGR duct 12 in the X direction And is set to extend through the position Sm. The position Sm that is the offset position of the center axis Lm of the mixed duct 3014 and the position Sa that is the offset position of the center axis La of the air duct 3013 are the center of curvature Cv, Ch is offset from the center of curvature Cv, Ch and the rotational axis Lv of the valve body 10 on the same side (for example, on the opposite side of the EGR duct 12 in the X direction) That is, the position Sm and the position Sa coincide with each other (for example, the position Sm is the same as the position Sa). With this structure, the central axis Lm of the mixing duct 3014 and the central axis La of the air duct 3013 are substantially coaxial with each other. The remaining structures of the air duct 3013 and the mixing duct 3014 not described above are the same as those of the air duct 13 and the mixing duct 14 of the first embodiment.

In the third embodiment, the predetermined intermediate rotational position P3 of the valve body 10 shown in Figs. 21A to 21C is changed from the fully closed rotational position P1 of the valve body 10 shown in Figs. 20A to 20C, The valve body 10 is completely displaced from the virtual air area Aa and maintains the fully opened state of the air duct 3013 over the entire rotational angle range Rcm of the valve body 10 which is in the state shown in Fig. In the third embodiment as well, the valve body 10 rotates the valve body 10 from the maximum limit rotational position P5 shown in Figs. 22A to 22C to the rotational position located before the maximum limited rotational position P5 Is completely displaced from the virtual EGR zone Ae throughout the angular range Rss to maintain the fully opened state of the EGR duct 12. [

The air duct 3013 is positioned at a position offset from the rotational axis Lv of the valve element 10 toward the opposite side of the EGR duct 12 with respect to the rotational axis Lv of the valve element 10 Sa, < / RTI > As a result, the air duct 3013 is spaced as much as possible from the EGR duct 12. In other words, the air duct 3013 is further separated from the EGR duct 12 as compared with the air duct 13 of the first embodiment. The rotational angle range Rcm of the valve body 10 from the fully closed rotational position P1 of the valve body 10 to the predetermined intermediate rotational position P3 of the valve body 10 can be increased have. Therefore, the required characteristics for reducing the pressure loss of the suction air can be reliably satisfied.

The position Sa at which the center axis La of the air duct 3013 extends through and the position Sm at which the center axis Lm of the mixing duct 3014 extends through the center of the valve body 10 And is offset by the same distance from the rotation axis Lv to the same side of the rotation axis Lv. The pressure loss of the suction air supplied from the air duct 3013 into the valve chamber 110 and output to the mixing duct 3014 is reduced to the fully closed rotational position P1 of the valve body 10 to the intermediate rotational position P3 of the valve body 10 can be reduced over the entire rotational angle range Rcm of the valve body 10. [ Therefore, the low-pressure EGR apparatus 1 of the third embodiment is particularly effective in that it satisfies the required characteristics of reducing the pressure loss of the intake air.

(Fourth Embodiment)

23 to 25, the fourth embodiment of the present invention is a modification of the first embodiment. In the EGR duct 4012 of the fourth embodiment, the central axis Le of the EGR duct 4012 extending through the curvature centers Cv, Ch and substantially perpendicular to the rotational axis Lv of the valve body 10 Forms an obtuse angle &thetas; ab between the central axis La and the central axis Le of the air duct 13. [ The center axis Le of the EGR duct 4012 forms an acute angle? Ms between the center axis Lm and the center axis Le of the mixing duct 14. [ The remaining structure of the EGR duct 4012 other than the above-described points is substantially the same as the structure of the EGR duct 12 of the first embodiment.

26A to 26C to the intermediate rotational position P3 of the valve body 10 shown in Figs. 27A to 27C from the fully closed rotational position P1 of the valve body 10 shown in Figs. 26A to 26C, The valve body 10 is completely displaced from the virtual air region Aa so as to maintain the fully opened state of the air duct 13 over the entire rotational angle range Rcm of the air flow passage 10. 28A to 28C to the rotational position in front of the maximum limit rotational position P5 as shown in Figs. 28A to 28C, the rotational angle range Rss of the valve body 10 The valve body 10 is completely displaced from the virtual EGR region Ae to maintain the fully opened state of the EGR duct 4012 throughout.

According to the fourth embodiment, the EGR duct 4012 having the central axis Le is spaced as much as possible from the air duct 13 having the central axis La and forming the obtuse angle? Ab with respect to the central axis Le do. In other words, the EGR duct 4012 is further separated from the air duct 13 in comparison with the EGR duct 12 of the first embodiment. The rotational angle range Rcm of the valve body 10 from the fully closed rotational position P1 of the valve body 10 to the predetermined intermediate rotational position P3 of the valve body 10 can be increased . Therefore, it is possible to reliably satisfy the required characteristics of reducing the pressure loss of the intake air.

(Fifth Embodiment)

29 to 31, the fifth embodiment of the present invention is a modification of the first embodiment and is a modification of the fourth embodiment. The central axis La of the air duct 5013 which extends through the center of curvature Cv and Ch and is substantially perpendicular to the rotation axis Lv of the valve body 10 in the air duct 5013 of the fifth embodiment, Forms an obtuse angle? Ab between the center axis Le of the EGR duct 12 and the central axis La. The remaining structure of the air duct 5013 other than the above-mentioned points is the same as the structure of the air duct 13 of the first embodiment.

In the fifth embodiment as well, the air duct 5013 is moved from the fully closed rotational position P1 of the valve element 10 shown in Figs. 32A to 32C to the middle of the valve element 10 shown in Figs. 33A to 33C And is completely opened over the entire rotation angle range (Rcm) of the valve body 10 up to the rotational position P3. At this time, the valve body 10 is completely displaced from the virtual air region Aa so as to maintain the fully opened state of the air duct 5013 over the entire rotation angle range (Rcm) of the valve body 10. [ In the fifth embodiment as well, the EGR duct 12 is fully opened at the maximum limit rotational position P5 shown in Figs. 34A to 34C. At this time, the valve body 10 is completely displaced from the virtual EGR region Ae to realize the fully opened state of the EGR duct 12 at the maximum limit rotational position P5.

In the fifth embodiment as well, from the fully closed rotational position P1 of the valve body 10 shown in Figs. 32A to 32C to the intermediate rotational position P3 of the valve body 10 shown in Figs. 33A to 33C, The valve element 10 is completely displaced from the virtual air area Aa so as to maintain the fully opened state of the air duct 5013 over the entire rotation angle range Rcm of the air duct 1013. [ In the fifth embodiment as well, the entire rotation angle range Rss of the valve body 10 from the maximum limit rotational position P5 to the maximum limit rotational position P5 shown in Figs. 34A to 34C The valve body 10 is completely displaced from the virtual EGR region Ae so as to maintain the fully opened state of the EGR duct 12 over the entire area.

According to the fifth embodiment, the EGR duct 12 having the center axis Le is spaced as much as possible from the air duct 5013 having the central axis La and forming the obtuse angle? Ab with respect to the central axis Le do. In other words, the EGR duct 12 is further separated from the air duct 5013 as compared with the EGR duct 12 of the first embodiment. The rotational angle range Rcm of the valve body 10 from the fully closed rotational position P1 of the valve body 10 to the predetermined intermediate rotational position P3 of the valve body 10 can be increased . Therefore, it is possible to reliably satisfy the required characteristics of reducing the pressure loss of the intake air.

(Other Embodiments)

The present invention has been described with reference to the above embodiments. However, the present invention is not limited to the above-described embodiments, and the above-described embodiments can be modified within the principles of the present invention.

Specifically, in the first modification, as shown in Fig. 35, the same mixing duct 3014 as the mixing duct 14 of the first embodiment can be used for the low-pressure EGR apparatus 1 of the third embodiment . In the second modification, as shown in Fig. 36, the EGR duct 2012 of the second embodiment and the air duct 3013 of the third embodiment can be used together. In the case of the second modification, as shown in Fig. 36, the mixing duct 3014 of the third embodiment can be used. Alternatively, although not shown, the mixing duct 14 of the first embodiment can be used in the case of the first modification described above.

In the third modification, the EGR duct 4012 of the fourth embodiment and the air duct 5013 of the fifth embodiment can be used together, as shown in Fig. Two valve shaft portions 102 each projecting from the two arm portions 101 toward the opposite side are formed by two bearing portions 112 each formed by a wall portion each forming two planar support surfaces 111, As shown in Fig.

In the fifth modified example, the valve element 10 is provided in any of the EGR ducts 12 of the first to fifth embodiments, at a portion other than the maximum limited rotational position P5 of the rotational angle range Rss of the valve body 10. [ , 2012, and 4012 may be partially overlapped with the virtual EGR region Ae. In the sixth modified example, in the entire range of the rotation angle range Rss of the valve body 10, the valve body 10 is configured such that any of the EGR ducts 12, 2012, and 4012 of the first to fifth embodiments is partially And can overlap with the virtual EGR region Ae to close it.

In the seventh modification, a gasoline engine using gasoline as fuel burned in each cylinder 30 may be used as the internal combustion engine 3 to which the present invention is applied. In the case of the seventh modification, the specific structure of the internal combustion engine 3 should not be limited to the structure described in the first embodiment.

Claims (8)

From the flow branching portion 320 of the exhaust passage 32 located on the downstream side of the turbine 20 of the turbocharger 2 provided in the internal combustion engine 3 to the upstream side of the compressor 21 of the turbocharger 2 Pressure EGR device for recirculating the EGR gas to the flow merging portion (310) of the intake passage (31) in which the EGR gas is mixed with the intake air guided to the intake passage (31)
A valve body (10) having a convex sealing surface (103) having a partial spherical shape is provided with a valve body (10) rotatable about a rotation axis (Lv) extending through a center of curvature (Cv) of a convex sealing surface (103) ;
As the valve housing 11,
A valve chamber (110) defining a flow merging portion (310) and receiving the valve body (10);
A valve housing (11) having a concave sealing surface (113) partially spherical in shape and exposed to the valve chamber (110) and having a concave sealing surface (113) slidingly contacting the convex sealing surface (103);
EGR ducts (12, 2012, 4012) for guiding EGR gas supplied from the flow branching section (320) to the valve chamber (110);
The air ducts 13, 3013 and 5013 forming the passage portion 311 of the intake passage 31 located on the upstream side of the flow merging portion 310 serve as air ducts for guiding the suction air to the valve chamber 110 Ducts (13, 3013, 5013); And
Wherein at least one of the EGR gas and the intake air is supplied from the valve chamber 110 to the mixing ducts 14 and 3014 forming the passage portion 312 of the intake passage 31 located on the downstream side of the flow merging portion 310, And a mixing duct (14, 3014) flowing out through the mixing duct (14, 3014)
The concave sealing surface 113 is located between the EGR ducts 12, 2012 and 4012 and the air ducts 13, 3013 and 5013,
And an inlet 130 of the air ducts 13, 3013 and 5013 into which the intake air is introduced into the valve chamber 110 and at least one of the EGR gas and the intake air flows out of the valve chamber 110 14, and 3014, the virtual air region Aa is formed as a virtual region that connects the outflow ports 140 of the first,
The valve body 10 is configured such that the valve body 10 is moved from the fully closed rotational position P1 of the valve body 10 which completely closes the EGR ducts 12, 2012 and 4012 to the EGR duct 12 , 2012, 4012 from the virtual air area Aa to the predetermined intermediate rotational position P3 of the valve body 10 partially opening the valve body 10, A low-pressure EGR device that completely opens the ducts (13, 3013, 5013). The method according to claim 1,
The center axis Le of the EGR duct 2012 is located at a position Se offset from the rotation axis Lv of the valve body 10 on the side opposite to the air duct 13 with respect to the rotation axis Lv of the valve body 10. [ Pressure EGR device. The method according to claim 1,
The center axis La of the air duct 3013 is located at a position Sa offset from the rotation axis Lv of the valve element 10 on the side opposite to the EGR duct 12 with respect to the rotation axis Lv of the valve element 10, Pressure EGR device. The method of claim 3,
The center axis La of the air duct 3013 and the center axis Lm of the mixing duct 3014 are connected to the rotation axis Lv of the valve body 10 at the same distance to the rotation axis Lv of the valve body 10 Lv), respectively, through the position (Sa) and the position (Sm). The method according to claim 1,
The obtuse angle? Ab is formed between the center axis Le of the EGR ducts 12 and 4012 and the center axis La of the air ducts 13 and 5013. The low- 6. The method according to any one of claims 1 to 5,
And the inlet 120 of the EGR ducts 12 2012 and 4012 into which the EGR gas flows into the valve chamber 110 and the mixing ducts 120 through which the EGR gas and the intake air flow out of the valve chamber 110 A virtual EGR region Ae is formed as a virtual region connecting the outflow ports 140 of the first and second exhaust ports 14 and 3014 at the shortest distance,
The valve body 10 is displaced from the imaginary EGR region Ae and the maximum restriction position P5 of the valve body 10 in which the flow restriction of the air ducts 13, 3013, 5013 by the valve body 10 is maximized, And the EGR ducts (12, 2012, 4012) are fully opened in the low-pressure EGR apparatus. 6. The method according to any one of claims 1 to 5,
The valve body 10
A sheet portion 100 forming a convex sealing surface 103; And
The rotation axis Lv of the valve body 10 extends from the seat portion 100 in the radial direction of the rotation axis Lv of the valve body 10 and is equal to or greater than the inner diameter of the air ducts 13, Pressure EGR device having two arm portions 101 that are spaced apart from each other in the direction of the arrow. 8. The method of claim 7,
The rotary shaft Lv of the valve body 10 intersects at least one of the central axis La of the air ducts 13,3013 and 5013 and the central axis Le of the EGR ducts 12,202 and 2012,
At least one of the two arm portions 101 includes a valve shaft portion 102 extending along the rotation axis Lv of the valve body 10 through the wall portion of the valve housing 11 and driven by the electric actuator 15, Pressure EGR device.

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