Orifice plate for a jet device

Abstract

An orifice plate for a jetting device has at least one fluid channel extending radially outward from a central region of the orifice plate and at least one orifice extending axially through the orifice plate. The at least one orifice has an entry region adjacent the at least one fluid channel, the entry region having a first diameter in the radial direction; an intermediate region adjacent the entry region on a side facing away from the fluid channel, the intermediate region having a second diameter in the radial direction, the second diameter being smaller than the first diameter; and an exit region adjacent the intermediate region on a side facing away from the entry region, the exit region having a third diameter in the radial direction, the third diameter being smaller than the second diameter. An entire inner boundary of the entry region, the intermediate region, and the exit region on an inner side of the orifice facing the central region extends along a straight line.

Description

Technical Field

[0001] The present invention relates to a nozzle disc for an injection device, particularly for an injection device configured to inject a liquid reducing agent into the exhaust gas system of an internal combustion engine. Background Technology

[0002] In order to reduce nitrogen oxides (NOx) in the exhaust gas of internal combustion engines, especially diesel engines. x The liquid reducing agent, in the form of an aqueous solution of urea (“AdBlue”®), is injected into the exhaust system of the internal combustion engine.

[0003] To produce the most uniform spray possible, it is essential to ensure that the reducing agent mixes well with the exhaust gas.

[0004] DE 10 2017 209 520 discloses a nozzle disk for an injection device configured to inject fluid, the nozzle disk having at least one discharge opening. A recess is constructed in the nozzle disk around the at least one discharge opening such that fluid can flow through the recess to the discharge opening, thereby causing at least a portion of the fluid to overflow the discharge opening and at least a portion of the overflowing fluid to be guided back into the discharge opening. Summary of the Invention

[0005] The objective of this invention is to provide a nozzle disk that provides a spray with high uniformity and clearly (or sharply) defined edges.

[0006] The nozzle disk constructed according to the invention has at least one fluid channel extending radially outward from a central region of the nozzle disk and at least one nozzle extending through the nozzle disk in an axial direction orthogonal to the radial direction. The at least one nozzle includes: an inlet region adjacent to the at least one fluid channel, the inlet region having a first diameter D1 radially; an intermediate region adjacent to the inlet region on a side opposite to the fluid channel, the intermediate region having a second diameter D2 radially, the second diameter being smaller than the first diameter D1; and an outlet region adjacent to the intermediate region on a side opposite to the inlet region, the outlet region having a third diameter D3 radially, the third diameter being smaller than the second diameter D2. The entire inner boundary of the inlet region, the intermediate region, and the outlet region, defined on the inner side of the nozzle facing the central region, extends along a straight line.

[0007] Embodiments of the present invention also include an injection device for injecting fluid into the exhaust gas system of an internal combustion engine, having a valve seat and a nozzle disk constructed according to the present invention, wherein a fluid discharge opening capable of being closed by a sealing element is formed in the valve seat, the nozzle disk being arranged on the side of the valve seat opposite to the sealing element.

[0008] Embodiments of the invention also include a system for injecting a fluidized reducing agent into the exhaust system of an internal combustion engine, comprising a fluid reservoir for storing the fluidized reducing agent, an injection device according to the invention arranged on the exhaust system, and a delivery module configured to deliver the reducing agent from the fluid reservoir to the injection device. Such a system particularly also includes a catalyst arranged downstream of a metering module in the exhaust system.

[0009] The spraying device equipped with the nozzle disk of the present invention produces a spray with high uniformity, thereby avoiding localized excess of the reducing agent. Furthermore, the spray produced using the nozzle disk of the present invention has a scharf-like boundary. This scharf-like spray reduces the amount of reducing agent reaching the relatively cold wall of the metering connector where the spraying device is installed. This reduces or avoids undesirable deposition of the reducing agent on the wall of the metering connector.

[0010] In one embodiment, the straight line that defines the entry region, the intermediate region, and the discharge region on the inner side of the nozzle facing the central region extends axially orthogonally to the plane of the nozzle disk.

[0011] A nozzle with an inner boundary extending orthogonally to the plane of the nozzle disk can be manufactured particularly easily and produces a spray with high uniformity and clear boundaries.

[0012] In one embodiment, the outer boundaries of the inlet region, the intermediate region, and the outlet region, which are defined on the outer side of the nozzle away from the central region, are constructed in a stepped manner. Here, the outer boundary has a plurality of adjacent regions that extend alternately in the axial and radial directions.

[0013] This produces a spray that meets the desired requirements of high uniformity and clear boundaries.

[0014] In one embodiment, the entry area has a diameter D1 of less than 1 mm, particularly a diameter D1 of 0.3 mm, and ends above the outer end side of the nozzle disk at a height H1 of 0.1 to 0.3 mm, particularly a height H1 of 0.15 mm.

[0015] In one embodiment, the intermediate region has a diameter D2 of less than 0.1 to 0.4 mm, particularly a diameter D2 of 0.19 mm, and ends above the outer end side of the nozzle disk at a height H2 of 0.05 to 0.25 mm, particularly at a height H2 of 0.1 mm.

[0016] In one embodiment, the discharge area has a diameter D3 of 0.08 to 0.3 mm, particularly a diameter D3 of 0.14 mm, and ends above the outer end side of the nozzle disk at a height H3 of 0.03 to 0.15 mm, particularly at a height H3 of 0.14 mm.

[0017] In one embodiment, the outer boundary of the inlet region, the intermediate region, and the outlet region, which are defined on the outer side of the nozzle away from the central region, has at least one inclined region that extends at an acute angle relative to the axial direction.

[0018] In one embodiment, the inclined region is oriented at an angle α between 30° and 60° relative to the axial direction, particularly at an angle of 45° relative to the axial direction.

[0019] A spray is produced by a nozzle that is bounded by an inclined region on the outer side of the nozzle, away from the central region, which satisfies the desired requirements of high uniformity and clear boundary of the spray.

[0020] In one embodiment, the nozzle disk has n nozzles, where n is a positive integer greater than or equal to "1".

[0021] In one embodiment, the nozzle disk is constructed with rotational symmetry around the central region of the nozzle disk by a factor of n.

[0022] By combining multiple nozzles, especially those arranged in a rotationally symmetrical manner, a spray can be produced in which the desired characteristics of clear boundaries and high uniformity are particularly prominent. Attached Figure Description

[0023] Embodiments of the present invention will now be described with reference to the accompanying drawings.

[0024] Figure 1 : A schematic diagram of a device for injecting a reducing agent stored in a tank into the exhaust gas system of an internal combustion engine;

[0025] Figure 2 : A schematic cross-sectional view showing the area on the exhaust gas system side of the injection device of the present invention;

[0026] Figure 3 : Show Figure 2 A cross-sectional view of the nozzle disk of the injection device shown;

[0027] Figure 4 : Shows a longitudinal cross-sectional view of the nozzle disk constructed according to the first embodiment;

[0028] Figure 5 : Shows a longitudinal cross-sectional view of the nozzle disk constructed according to the second embodiment. Detailed Implementation

[0029] Figure 1 A schematic diagram of an apparatus is shown for injecting a fluid reducing agent 18 (fluid 18) stored in a storage tank 26, in particular an aqueous urea solution (“AdBlue”®), into the exhaust system 20 of an internal combustion engine 22, in particular a diesel engine 22.

[0030] During operation of the device, the reducing agent 18 is taken from the storage tank 26 and delivered by the transfer pump 30 under increased pressure via a suitable pressure line 32 to the injection device 2 installed on the metering connector 34 of the exhaust gas system 20. The injection device 2 sprays the reducing agent 18 as a spray 19 into the exhaust gas system 20. In the exhaust gas system 20, the injected reducing agent 18 mixes with the exhaust gas 24 flowing through the internal combustion engine 22 and reacts with the nitrogen oxides contained in the exhaust gas 24 in a catalytic converter 36 located downstream of the injection device 2 in the exhaust gas system 20.

[0031] Figure 2 A schematic cross-sectional view showing the area on the exhaust system side of the injection device 2.

[0032] The injection device 2 includes a nozzle disk 8 facing the exhaust gas system 20, in which a plurality of nozzles 10 are formed. Through these nozzles 10, the fluidized reducing agent 18 can flow from the interior of the injection device 2 into the exhaust gas system 20.

[0033] A valve seat 6, including a fluid discharge opening 7, is constructed on the side of the nozzle disk 8 facing away from the exhaust gas system 20. This fluid discharge opening 7 can be opened and closed by a closing element (valve ball) 4 movably supported in the valve sleeve 5 along the longitudinal axis A. Thus, the injection of the fluid reducing agent 18 into the exhaust gas system 20 can be controlled and directed.

[0034] The sealing element 4 is moved by an actuator (not shown) which is driven by a control device (also not shown) to inject a desired amount of fluid reducing agent 18 into the exhaust gas system 20.

[0035] Figure 3 Showing the orifice disk 8 along Figure 2 The cross-sectional view of the cutting line BB is shown in the figure.

[0036] exist Figure 3In the embodiment shown, the nozzle disk 8 has four nozzles 10, which are arranged in a four-fold symmetry, that is, in an equilateral and right-angled cross shape around the center Z of the nozzle disk 8. Figure 1 The longitudinal axis A shown is perpendicular to Figure 3 The drawing plane passes through the center Z of the nozzle disk 8.

[0037] In other embodiments not shown in the figures, more or fewer than four nozzles 10 may be constructed in the nozzle disk 8. Preferably, up to ten nozzles 10 may be constructed in the nozzle disk 8.

[0038] Starting from the fluid discharge opening 7 in the valve seat 6, the reducing agent 18 passes through the fluid channel 9 constructed between the valve seat 6 and the nozzle plate 8 (see...). Figure 2 ) flows to nozzle 10.

[0039] exist Figure 3 The possible flow path 40 of the reducing agent 18 is shown by streamline 40. Figure 3 As can be seen, the flow path 40 does not simply extend in a straight line from the center Z of the nozzle disk 8 to the nozzle 10. A portion of the reducing agent 18 first flows past the nozzle 10 in the area of ​​the nozzle disk 8 without the nozzle 10, so that it then flows in a star-shaped pattern into one of the nozzles 10. The advantageous effect of this flow pattern is that the reducing agent 18 flows into the corresponding nozzle 10 with high turbulence. This turbulence results in the formation of particularly small reducing agent droplets, which mix particularly well with the exhaust gas 24 in the exhaust gas system 20.

[0040] Figure 4 A longitudinal cross-sectional view of a nozzle disk 8 constructed according to an embodiment of the present invention is shown.

[0041] The nozzle disk 8 typically has a diameter D0 of 2 to 6 mm, particularly about 4 mm, and a height H0 of 0.15 to 0.4 mm, particularly about 0.2 mm.

[0042] exist Figure 4 The diagram shows two nozzles 10. These nozzles 10 are constructed relative to the longitudinal axis A at a spacing R of, for example, 0.2 to 1.5 mm, and particularly at a spacing of about 0.8 mm, which extends axially through the center Z of the nozzle disk 8.

[0043] Each nozzle 10 has an inner boundary 10a on its inner side facing the center Z, which extends linearly in the axial direction and parallel to the longitudinal axis A and thus extends orthogonally to the flat outer end side 8a of the nozzle disk 8.

[0044] Each nozzle 10 has an outer boundary 10b, 10c opposite the inner boundary 10a, which is constructed in a stepped or stair-like shape. The outer boundaries 10b, 10c have alternating adjacent horizontal regions 10b and vertical regions 10c, the horizontal regions extending radially orthogonal to the longitudinal axis A, and the vertical regions extending axially parallel to the longitudinal axis A.

[0045] Due to the stepped or stair-shaped outer boundaries 10b and 10c, the nozzle 10 has three axially adjacent regions 12, 14, and 16, which have other diameters D1, D2, and D3 respectively:

[0046] The nozzle 10 has: an inlet region (first or uppermost region) 12 directly adjacent to the fluid channel 9, the inlet region having a first diameter D1 < 1 mm in the radial direction; an intermediate region 14 (second or middle region) adjacent to the inlet region 12 on the side opposite to the fluid channel 9, the intermediate region having a second diameter 0.1 mm < D2 < 0.4 mm in the radial direction, the second diameter being smaller than the first diameter D1; and an outlet region 16 (third or lower region) adjacent to the intermediate region 14 on the side opposite to the inlet region 12, the outlet region having a third diameter 0.08 mm < D3 < 0.3 mm in the radial direction, the third diameter being smaller than the second diameter D2.

[0047] That is, for each nozzle 10, the following applies: D3 < D2 < D1.

[0048] The discharge area 16 has a height H3 between 0.03 mm and 0.15 mm, particularly 0.05 mm, measured from the end side 8a of the nozzle disk 8 in the axial direction, that is, in the direction parallel to the longitudinal axis A.

[0049] The upper edge of the intermediate region 14 is constructed along the axial direction above the end side 8a of the nozzle disk 8 at a height H2 between 0.05 mm and 0.25 mm, particularly 0.1 mm.

[0050] The upper edge of the entry area 12 is constructed along the axial direction above the end side of the nozzle disk 8 at a height H1 between 0.1 mm and 0.3 mm, particularly 0.15 mm.

[0051] The diameters D1, D2, D3 and heights H1, H2, H3 described above are merely exemplary and can be adapted as needed to generate spray 19 as well as possible to the corresponding exhaust gas system 20.

[0052] In other embodiments not shown in the figure, the outer boundaries 10b, 10c of the nozzle 10 may also have more than [missing information]. Figure 4The two steps shown. That is, instead of... Figure 4 The only intermediate area 14 shown can also be provided with more stair-shaped intermediate areas 14 that are adjacent to each other and have different diameters D1, D2, D3.

[0053] exist Figure 4 The flow of reducing agent 18 is also schematically shown through streamlines 42 and 44.

[0054] The asymmetric configuration of nozzle 10 described earlier has the following consequences: asymmetric flow through nozzle 10:

[0055] The flow through the nozzle 10 includes, in particular, a flow portion 42 flowing from the outside to the inside of the nozzle 10 and a flow portion 44 flowing from the inside to the outside of the nozzle 10.

[0056] Compared to the flow portion 42 that flows from the outside to the inside through the nozzle 10, the flow portion 44 that flows from the inside to the outside through the nozzle 10 flows through the nozzle 10 at a steeper angle, that is, at a smaller angle relative to the axial direction / longitudinal axis A.

[0057] Compared to the flow portion 42 that flows from the outside to the inside through the nozzle 10 (for which the nozzle 10 has a larger width D1 (D1 > D3) in the entry region 12), the ratio L / D3 between the length (height) L=H1 and the diameter D3 of the nozzle 10 is greater for the flow portion 44 that flows from the inside to the outside through the nozzle 10.

[0058] Therefore, the flow portion 44 flowing from the inside out is more strongly guided compared to the flow portion 42 flowing from the outside in, resulting in less turbulence. Due to the less turbulence, the outer boundary of the spray 19 has sharper edges on the outer side opposite to the longitudinal axis A.

[0059] Compared to the flow portion 44 which flows from the inside out, the ratio L / D1 between the length (height) L=H1 and the diameter D1 of the nozzle 10 is smaller for the flow portion 42 which flows from the outside in.

[0060] As a result, less of the flow portion 42 flowing from the outside to the inside is guided, which results in greater turbulence.

[0061] Due to the greater turbulence, the edges of the spray 19 are less scharfkantiged inward, that is, towards the center Z or longitudinal axis A of the nozzle disk 8, which results in greater uniformity of the spray 19.

[0062] This produces a spray 19 that not only has high uniformity but also has a clear (or sharp) outer edge.

[0063] Figure 5 An alternative embodiment of the nozzle disk 8 of the present invention is shown.

[0064] According to Figure 5 In the nozzle disk 8 of the embodiment shown, the outer boundary 10b of the nozzle 10 is not straight in the intermediate region 14, but is constructed inclined to the axial direction or longitudinal axis A, so that the outer boundary 10b has at least one inclined region 10d.

[0065] The outer boundary 10b of the intermediate region 14 is oriented relative to the axial direction or longitudinal axis A, for example at an angle α between 30° and 60°, particularly at an angle α of 45°.

[0066] In this embodiment, the diameters D1 and D3 of the entry area 12 and the heights H2 and H3 of the discharge area 16 are also correspondingly... Figure 4 The corresponding dimensions of the embodiments shown are in this Figure 4 In one embodiment, the outer boundary of the nozzle 10 is constructed in a stepped shape.

[0067] No. 8 nozzle plate Figure 5 The embodiment shown also produces a spray 19 that not only has the desired high uniformity but also has a clear (or sharp) outer edge.

Claims

1. A nozzle disk (8) having at least one fluid passage (9) extending radially outward from a central region of the nozzle disk (8) and at least one nozzle (10) extending axially through the nozzle disk (8). Its features are, The at least one nozzle (10) has: An entry region (12) adjacent to the at least one fluid channel (9) has a first diameter (D1) in the radial direction. A middle region (14) adjacent to the entry region (12) on the side opposite to the fluid channel (9) has a second diameter (D2) in the radial direction. The discharge area (16) is adjacent to the intermediate area (14) on the side opposite to the entry area (12), and the discharge area has a third diameter (D3) in the radial direction, which is smaller than the second diameter (D2). Wherein, the second diameter (D2) is smaller than the first diameter (D1), or the outer boundary (10b, 10c) of the nozzle (10) defining the entry region (12), the intermediate region (14) and the discharge region (16) on the outer side away from the central region has at least one inclined region (10d), which extends at an acute angle (α) relative to the axial direction. The entire inner boundary (10a) of the inlet region (12), the middle region (14) and the outlet region (16) of the nozzle (10) extending along a straight line on the inner side of the nozzle (10) facing the central region, wherein the straight line extends orthogonally to the plane of the nozzle disk (8) in the axial direction.

2. The nozzle disk (8) according to claim 1, wherein, The outer boundaries (10b, 10c) of the inlet region (12), the middle region (14) and the outlet region (16) of the nozzle (10) are constructed in a stepped manner on the outer side of the nozzle (10) away from the central region, wherein the outer boundaries (10b, 10c) have a plurality of adjacent regions (10b, 10c) that extend alternately in the axial direction and in the radial direction.

3. The nozzle disk (8) according to claim 2, wherein, The entry area (12) has a diameter (D1) of less than 1 mm and ends at a height (H1) of 0.1 to 0.3 mm above the outer end side (8a) of the nozzle disk (8); The intermediate region (14) has a diameter (D2) of 0.1 to 0.4 mm and ends at a height (H2) of 0.05 to 0.25 mm above the outer end side (8a) of the nozzle disk (8); The discharge area (16) has a diameter (D3) of 0.08 to 0.3 mm and ends at a height (H3) of 0.03 to 0.15 mm above the outer end side (8a) of the nozzle disk (8).

4. The nozzle disk (8) according to claim 1, wherein, The inclined region (10d) extends at an angle (α) between 30° and 60° relative to the axial direction.

5. The nozzle disk (8) according to any one of claims 1 to 4, wherein, The nozzle disk (8) has n nozzles (10), where n is an integer greater than "1".

6. The nozzle disk (8) according to claim 3, wherein, The entry area (12) has a diameter (D1) of 0.3 mm.

7. The nozzle disk (8) according to claim 3, wherein, The entry area (12) ends at a height (H1) of 0.15 mm above the outer end side (8a) of the nozzle disk (8).

8. The nozzle disk (8) according to claim 3, wherein, The intermediate region (14) has a diameter (D2) of 0.19 mm.

9. The nozzle disk (8) according to claim 3, wherein, The intermediate region (14) ends at a height (H2) of 0.1 mm above the outer end side (8a) of the nozzle disk (8).

10. The nozzle disk (8) according to claim 3, wherein, The discharge area (16) has a diameter of 0.14 mm.

11. The nozzle disk (8) according to claim 3, wherein, The discharge area (16) ends at a height (H3) of 0.14 mm above the outer end side (8a) of the nozzle disk (8).

12. The nozzle disk (8) according to claim 4, wherein, The inclined region (10d) extends at an angle of 45° relative to the axial direction.

13. The nozzle disk (8) according to claim 5, wherein, The nozzle disk (8) has a central region arranged with rotational symmetry of n times around the nozzle disk (8).

14. An injection device (2) for injecting a fluid reducing agent (18) into an exhaust gas system (20) of an internal combustion engine (22), having a valve seat (6) and a nozzle disk (8) according to any one of claims 1 to 13, wherein a fluid discharge opening (7) capable of being closed by a sealing element (4) is constructed in the valve seat, the nozzle disk being arranged on the side of the valve seat (6) opposite to the sealing element (4).

15. A system for injecting a fluidized reducing agent (18) into an exhaust gas system (20) of an internal combustion engine (22), comprising a fluid storage tank (26) for storing the fluidized reducing agent (18), an injection device (2) arranged on the exhaust gas system (20), and a delivery module (30) configured to deliver the reducing agent (18) from the fluid storage tank (26) to the injection device (2), wherein, The spraying device (2) is the spraying device (2) according to claim 14.

16. A system for reducing harmful substances in the exhaust gas (24) of an internal combustion engine (22), wherein, The system includes a system for injecting a fluid reducing agent into an exhaust gas system (20) of an internal combustion engine (22) as claimed in claim 15 and a catalyst (36) arranged downstream of the injection device (2) in the exhaust gas system (20).

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