Internal combustion engine

Abstract

An internal combustion engine may include a housing and at least one cavity arranged therein for receiving a coolant flow. An exhaust gas cooler may be provided for cooling an exhaust gas flow. The exhaust gas cooler may be configured as a stacked disc cooler including at least two stacking discs, an exhaust gas inlet, a cover plate and a screw-mounting plate for screw-mounting to the housing. The exhaust gas cooler may protrude into the cavity of the housing when the screw-mounting plate is mounted to the housing. The screw-mounting plate may have a spacer element disposed at the exhaust gas inlet. The spacer element may protrude in a direction of the at least two stacking discs and enlarge a distance between the screw-mounting plate and an adjacent stacking disc of the at least two stacking discs to position the exhaust gas cooler further into the cavity.

Claims

1. An internal combustion engine, comprising: a housing and at least one cavity arranged in the housing for receiving a coolant flow; an exhaust gas cooler for cooling an exhaust gas flow to be supplied to a combustion process; the exhaust gas cooler configured as a stacked disc cooler including at least two stacking discs, an exhaust gas inlet, a cover plate and a screw-mounting plate for screw-mounting to the housing; the exhaust gas cooler protrudes into the at least one cavity of the housing through which the coolant flow is received; wherein the screw-mounting plate includes a spacer element disposed at least at the exhaust gas inlet, the spacer element defining at least part of the exhaust gas inlet for guiding the exhaust gas flow into the exhaust gas cooler, wherein the spacer element protrudes in a direction of the at least two stacking discs and enlarges a distance between the screw-mounting plate and an adjacent stacking disc of the at least two stacking discs to position the exhaust gas cooler further into the cavity; and wherein the spacer element is structured as a baffle element for influencing the exhaust gas flow through the exhaust gas cooler.

2. The internal combustion engine according to claim 1, wherein the at least two stacking discs and the screw-mounting plate are secured together via at least one of a soldered connection, a welded connection and a bolted connection.

3. The internal combustion engine according to claim 1, wherein the spacer element has an internal cross-section defining an extent smaller in a region of the adjacent stacking disc than a region of the screw-mounting plate.

4. The internal combustion engine according to claim 1, wherein a depth of the spacer element is at least 5 mm.

5. The internal combustion engine according to claim 1, wherein a distance between an exhaust gas channel defined by the at least two stacking discs and the screw-mounting plate is at least 8 mm.

6. The internal combustion engine according to claim 1, wherein a height of an exhaust gas channel formed by the at least two stacking discs is between 4 mm and 8 mm.

7. The internal combustion engine according to claim 1, wherein a height of a coolant flow channel defined by the at least two stacking discs is between 2 mm and 10 mm.

8. The internal combustion engine according to claim 1, wherein the exhaust gas cooler further includes an exhaust gas outlet, and wherein at least one of: an embossed deflection channel is disposed on the screw-mounting plate in a region of the exhaust gas outlet, and an intermediate plate is arranged between the screw-mounting plate and an adjacent stacking disc of the at least two stacking discs, and wherein the intermediate plate has another spacer element arranged at the exhaust gas outlet and protruding in a direction of the adjacent stacking disc.

9. The internal combustion engine according to claim 1, further comprising an exhaust gas recirculation valve arranged on the screw-mounting plate in a region of the exhaust gas inlet.

10. The internal combustion engine according to claim 9, wherein the exhaust gas recirculation vale is secured to the screw-mounting plate via threaded bolts, and wherein the threaded bolts are arranged on the screw-mounting plate.

11. The internal combustion engine according to claim 1, further comprising a surface-enlarging structure disposed on an external side of the spacer element with respect to the exhaust gas flow.

12. The internal combustion engine according to claim 1, wherein the spacer element has a dish shape defining an internal cross-section that decreases in the direction of the at least two stacking discs.

13. The internal combustion engine according to claim 12, wherein the spacer element is a separate spacer piece connected to the screw-mounting plate via at least one of a welded connection, a soldered connection and a bolted connection.

14. The internal combustion engine according to claim 13, wherein the separate spacer piece includes at least one of a plate, a ring, a bush and a sleeve.

15. The internal combustion engine according to claim 11, wherein the surface-enlarging structure includes at least one of a bead, a stud and a rib.

16. The internal combustion engine according to claim 12, wherein the spacer element is integral with the screw-mounting plate.

17. The internal combustion engine according to claim 1, further comprising an intermediate plate arranged between the screw-mounting plate and one stacking disc of the at least two stacking discs, and wherein the intermediate plate at an exhaust gas outlet of the exhaust gas cooler includes another spacer element arranged in a direction of the one stacking disc.

18. An internal combustion engine, comprising: a housing and at least one cavity disposed in the housing for receiving a coolant flow; an exhaust gas cooler for cooling an exhaust gas flow supplied to a combustion process, the exhaust gas cooler including a plurality of stacking discs, an exhaust gas inlet, and exhaust gas outlet, a cover plate and a mounting plate for connecting the exhaust gas cooler to the housing; the exhaust gas cooler protrudes into the cavity of the housing; a spacer element projecting from the mounting plate at the exhaust gas inlet, the spacer element defining at least part of the exhaust gas inlet for guiding the exhaust gas flow into the exhaust gas cooler, wherein the spacer element protrudes in a direction of the at least two stacking discs and enlarges a distance between the mounting plate and a proximate stacking disc of the plurality of stacking discs to position the exhaust gas cooler further into the cavity; and wherein the spacer element has a dish shape defining an internal cross-section that decreases in the direction of the at least two stacking discs.

19. The internal combustion engine according to claim 18, wherein the spacer element is structured as a baffle element in a region of the proximate stacking disc for influencing the exhaust gas flow through the exhaust gas cooler.

20. The internal combustion engine according to claim 18, further comprising a surface-enlarging structure disposed on an external side of the spacer element in a region defining at least part the exhaust gas inlet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The drawings show diagrammatically,

(2) FIG. 1 a cross-section view through an internal combustion engine according to the invention,

(3) FIG. 2 a depiction of a detail in the region of an exhaust gas inlet from FIG. 1 with a spacer element formed as a dish,

(4) FIG. 3 a front view of an exhaust gas cooler,

(5) FIG. 4 a top view and a section view through an exhaust gas cooler with exhaust gas recirculation valve,

(6) FIG. 5 a depiction of a detail in the region of an exhaust gas inlet with a spacer element formed a separate spacer piece.

DETAILED DESCRIPTION

(7) According to FIGS. 1, 2 and 5, an internal combustion engine 1 according to the invention has a housing 2 with a cavity 3 arranged therein. A coolant 12 flows through the cavity 3 and thus cools the internal combustion engine 1. Furthermore, the internal combustion engine 1 according to the invention has an exhaust gas cooler 4 (see also FIGS. 3 and 4) for cooling an exhaust gas to be supplied to a combustion process. Due to the exhaust gas recirculation, in particular the nitrous oxides and particulate emissions are reduced.

(8) Looking further at FIGS. 1 to 5, we see that the exhaust gas cooler 4 is formed as a stacked disc cooler and has a plurality of stacking discs 5, a cover plate 6 and a screw-mounting plate 7 for screw-mounting to the housing 2 of the internal combustion engine 1.

(9) As can be seen particularly clearly from FIG. 1, in the state mounted, i.e. screw-mounted, on the housing 2, the exhaust gas cooler 4 protrudes into the cavity 3 of the housing 2 through which the coolant 12 flows, so that coolant 12 flowing into the cavity 3 can flow through the stacking discs 5.

(10) According to the invention, the screw-mounting plate 7, at least at an exhaust gas inlet 8, also has a spacer element 9 formed in the direction of the adjacent stacking disc 5, i.e. here in the Y-direction, which increases the distance between the screw-mounting plate 7 and the adjacent stacking disc 5, and hence positions the gas cooler 4 more deeply in the cavity 3 in the Y-direction. This achieves in particular a better flow of coolant 12 through the stacking discs 5, i.e. the heat transmission block of the exhaust gas cooler 4, and hence these are cooled better. The spacer element 9 may be configured either as a dish 24 (see FIG. 2) formed integrally from the screw-mounting plate 7, or as a separate spacer piece 25 (see FIG. 5), in particular a plate, a ring, a sheet metal element, a sleeve or a bush. The latter is then connected, in particular bolted, soldered or welded, to the screw-mounting plate 7. In addition or alternatively, it may also be connected to the first stacking disc 5.

(11) Independently of the embodiment of the spacer element 9, this may have a surface-enlarging structure 26 on the outside, in particular beads, studs or ribs, as shown for example in FIGS. 2 and 5. In this way, because of the enlarged surface area, the heat transmission can be significantly improved in particular in the temperature-critical region of the exhaust gas inlet 8.

(12) Suitably, at least the stacking discs 5 and the screw-mounting plate 7 are soldered, welded or bolted together. Evidently, normally the entire exhaust gas cooler 4, consisting of the cover plate 6, stacking discs 5 and screw-mounting plate 7, is soldered so that the exhaust gas cooler 4 can not only be produced reliably sealed and systematically, but also at the same time preassembled.

(13) In a further advantageous embodiment of the solution according to the invention, the spacer element 9 is simultaneously configured as a baffle element 10 and in this way forces an even flow of exhaust gas 11 through the exhaust gas cooler 4 which is optimal in regard to heat transmission. A depth a of the spacer element 9 here is at least 5 mm, as shown according to FIG. 2, whereby it is possible to install the exhaust gas cooler 4 deeply in the cavity 3 of the housing 2 of the internal combustion engine 1 and hence arrange the exhaust gas cooler 4 in the main coolant flow. A distance b between an exhaust gas channel 13 formed by two stacking discs 5 and the screw-mounting plate 7 is at least 8 mm.

(14) A coolant channel 14 through which the coolant 12 flows is in each case arranged between two adjacent exhaust gas channels 13. A height h.sub.AGK of an exhaust gas channel 13 formed by two stacking discs 5 is here between 4 and 8 mm, whereas a height h.sub.KFK of a coolant channel 14 formed between two stacking discs 5 is between 2 mm and 10 mm, in particular between 2 mm and 5 mm. Evidently turbulence inserts 15 may be provided in the exhaust gas channel 13 which force an eddying of the exhaust gas 11 flowing in the exhaust gas channel 13 and thus improve the heat transmission. In the same way, studs 16 (see FIG. 2) may be arranged in the coolant channel 14 and cause an eddying of the coolant 12 and hence also improve the heat transmission.

(15) Looking again at FIG. 2, we see that an intermediate disc 17 is arranged between the screw-mounting plate 7 and the immediately adjacent stacking disc 5, which at an exhaust gas outlet 18 (see FIGS. 1 and 3 and 4) has a dish 9′ formed in the direction of the adjacent stacking disc 5. In this way it is possible to form a deflection channel 19 between the intermediate disc 17 and the screw-mounting plate 7, by means of which the cooled exhaust gas 11 emerging from the exhaust gas cooler 4 may for example be conducted into an exhaust gas overflow channel 20 (see FIG. 1), and guided in the housing 2 of the internal combustion engine 1, i.e. in the engine block, on the cold side of the internal combustion engine 2. Furthermore, passage openings 21 (see in particular FIGS. 3 and 4) are provided in the screw-mounting plate 7, which are designated as screw holes and via which the screw-mounting plate 7 and hence the exhaust gas cooler 4 can be screw-mounted to the housing 2 of the internal combustion engine 1.

(16) In order to be able also to attach an exhaust gas recirculation valve 22 (see FIG. 4) to the screw-mounting plate 7 and hence to the exhaust gas cooler 4 as easily and quickly as possible, threaded bolts 23 may be provided on the screw-mounting plate 7, on which the exhaust gas recirculation valve 22 is positioned and secured by means of nuts (not shown). In this way, in particular, preassembly of the exhaust gas recirculation valve 23 to the exhaust gas cooler 4 is possible. The two threaded bolts 23 also allow positioning of the exhaust gas recirculation valve 22 relative to the screw-mounting plate 7, wherein the exhaust gas recirculation valve 22 is bolted directly to the engine block, i.e. the housing 2 of the internal combustion engine 1, at the other passage openings 21, via the screw-mounting plate 7.

(17) With the internal combustion engine 1 according to the invention, the following advantages can be achieved: a high degree of integration, a significantly improved thermal fatigue strength due to excellent flushing of the exhaust gas inlet 8 and the achieved distance b between a screw-mounting plane and the plane of the first exhaust gas channel 13, simple mounting of an exhaust gas recirculation valve 22 by corresponding threaded bolts 23 on the screw-mounting plate 7, simple bolting of the exhaust gas recirculation valve 22 to the housing 2 (as far as possible) of the internal combustion engine 1, whereby low vibration loads are transmitted to the exhaust gas cooler 4, preassembly of the exhaust gas recirculation valve 22 to the screw-mounting plate 7 by the threaded bolts 23, integration of a deflection channel 19 by the use of an additional intermediate disc 17.