Air Gap-Insulated Muffler

Abstract

A muffler, in particular an end muffler, is provided for an exhaust system in a vehicle. The muffler has a muffler housing that has an exhaust intake pipe via which exhaust flows into the muffler housing as well as an exhaust discharge pipe via which exhaust flows out of the muffler housing. At least part of the muffler housing or the entire muffler housing is surrounded by an outer housing, and an air gap is provided between the muffler housing and the outer housing.

Claims

1. A muffler for an exhaust gas system of a vehicle, comprising: a muffler housing having an exhaust gas inlet pipe, via which exhaust gas flows into the muffler housing, and an exhaust gas outlet pipe, via which exhaust gas flows out of the muffler housing; a casing housing surrounding at least part of the muffler housing or an entirety of the muffler housing, wherein an air gap is provided between the muffler housing and the casing housing.

2. The muffler as claimed in claim 1, wherein the casing housing is held spaced apart from the muffler housing by way of spacer elements.

3. The muffler as claimed in claim 1, wherein the casing housing is spaced apart from the muffler housing by between 0.3 cm and 2.0 cm

4. The muffler as claimed in claim 1, wherein the casing housing is spaced apart from the muffler housing by between 0.8 cm and 1.2 cm.

5. The muffler as claimed in claim 1, wherein the casing housing has an inlet for fresh air.

6. The muffler as claimed in claim 5, wherein the inlet for fresh air is designed in a funnel or fan-shaped manner or as an air guide blade, and is provided for guiding incident fresh air into the air gap of the casing housing.

7. The muffler as claimed in claim 5, further comprising: a blower which delivers fresh air from the surroundings via the inlet for fresh air into the casing housing.

8. The muffler as claimed in claim 1, wherein the casing housing has an air outlet, via which air that is heated by the muffler housing can flow out into the surroundings from the casing housing.

9. The muffler as claimed in claim 1, wherein the exhaust gas outlet pipe ends within the casing housing, which results in a suction jet pump effect that delivers heated air out of the air gap via the air outlet into the surroundings.

10. The muffler as claimed in claim 1, wherein the casing housing is of tubular design in a region of the exhaust gas outlet pipe and is arranged coaxially with respect to the exhaust gas outlet pipe, and the exhaust gas outlet pipe ends within a tubular section of the casing housing.

11. The muffler as claimed in claim 1, wherein the muffler housing is made of steel or a titanium alloy.

12. The muffler as claimed in claim 1, wherein the casing housing is made of steel or a titanium alloy.

13. The muffler as claimed in claim 1, wherein the muffler is an end muffler of the exhaust gas system.

14. A vehicle, comprising: an internal combustion engine; and an exhaust gas system having a muffler, the muffler comprising: a muffler housing having an exhaust gas inlet pipe, via which exhaust gas flows into the muffler housing, and an exhaust gas outlet pipe, via which exhaust gas flows out of the muffler housing; a casing housing surrounding at least part of the muffler housing or an entirety of the muffler housing, wherein an air gap is provided between the muffler housing and the casing housing.

15. The vehicle as claimed in claim 14, further comprising: a fan which blows fresh air from the surroundings via an inlet for fresh air into the casing housing.

16. The vehicle as claimed in claim 14, wherein the muffler has a longitudinal direction which is parallel to either a transverse direction of the vehicle or a longitudinal direction of the vehicle.

17. The vehicle as claimed in claim 14, wherein the muffler is arranged in either a front car region or a rear car region of the vehicle.

18. The vehicle as claimed in claim 14, wherein the muffler is arranged in a lower front car region, the lower front car region is separated from an upper front car region via a bulkhead, and the bulkhead is composed completely or partially of a fiber-reinforced plastic material.

19. The vehicle as claimed in claim 15, wherein the fan is arranged in front of the muffler viewed in a driving direction of the vehicle.

20. The vehicle as claimed in claim 15, further comprising: an air-refrigerant heat exchanger of a refrigerant circuit of the vehicle, the heat exchanger being arranged in front of the muffler and/or in front of the fan as viewed in a vehicle driving direction of the vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 illustrates a fundamental principle of the invention in a diagrammatic illustration.

[0030] FIG. 2 also illustrates a fundamental principle of the invention in a diagrammatic illustration.

[0031] FIG. 3 is a section view through a front car region of a vehicle, in which an end muffler according to an embodiment of the invention is arranged.

DETAILED DESCRIPTION OF THE DRAWINGS

[0032] FIG. 1 shows an end muffler 1 which is arranged transversely in a vehicle (not shown in greater detail here). “Transversely” means that a longitudinal direction 2 of the end muffler 1 extends transversely or substantially perpendicularly with respect to a driving direction of the vehicle, which driving direction is indicated by way of an arrow 3. The arrow 3 is therefore substantially parallel to the longitudinal direction of the vehicle.

[0033] The muffler 1 has an exhaust gas inlet pipe 4, via which exhaust gas can flow into a housing 1a of the muffler 1. Furthermore, the “muffler housing” 1a has an exhaust gas outlet pipe 5, via which exhaust gas can flow out of the muffler 1.

[0034] As can be seen from FIG. 1, the entire muffler housing 1a is surrounded by a casing (outer) housing 6. The casing housing 6 is arranged at a spacing from the muffler housing 1a, which results in an air gap 7 between the casing housing 6 and the muffler housing 1a. The air gap can lie, for example, in the range between 0.3 cm and 2.0 cm, in particular in the range between 0.8 cm and 1.2 cm. The air gap results in thermal insulation. The surface temperature of the casing housing 6 is therefore considerably lower than the surface temperature of the end muffler housing 1a.

[0035] The end muffler housing 1a and/or the casing housing 6 can consist, for example, of a metal material, such as steel, an aluminum alloy or another sufficiently temperature-resistant material.

[0036] The casing housing 6 is of tubular design in the region of the exhaust gas outlet pipe 5. A tubular section 6a of the casing housing extends substantially coaxially with respect to the exhaust gas outlet pipe 5 of the muffler 1. As can be seen from FIG. 1, however, the exhaust gas outlet pipe 5 ends “within the casing housing 6 or within the tubular section 6a of the casing housing 6”. In other words, the tubular section 6a of the casing housing projects beyond the exhaust gas outlet pipe 5.

[0037] Furthermore, the casing housing 6 has a funnel-like or fan-like inlet 8 for fresh air. As viewed in the driving direction 3 of the vehicle, the inlet 8 is arranged on a front side or in the region of a front side 9 of the muffler 1. Furthermore, two blowers 10a, 10b which blow fresh air from the surroundings in the direction of the inlet 8 are provided in the region of the front side 9.

[0038] The muffler housing 1a is cooled by way of the fresh air which flows into the casing housing 6 via the inlet 8. The air which is heated by the muffler housing 1a exits laterally again via the air outlet 6a.

[0039] A suction jet pump effect results on account of the exhaust gas which flows through the muffler 1 and the fact that the air outlet 6a projects beyond the exhaust gas outlet pipe 5. This suction jet pump effect improves the air circulation from the surroundings via the inlet 8, through the gap of the casing housing 6 to the air outlet 6a. This circulation is additionally assisted by way of the airflow which is produced by the two blowers 10a, 10b.

[0040] FIG. 2 shows one variant, in which the end muffler 1 is installed longitudinally in the vehicle, that is to say a longitudinal axis 2 of the end muffler 1 is parallel here to the driving direction 3 or to the vehicle longitudinal direction.

[0041] FIG. 3 shows an installation situation, in which the muffler 1 is accommodated in a front underbody region of a vehicle. A blower 10a is arranged in front of the end muffler 1 in the driving direction 3. A high temperature cooler 11 is provided in front of the blower, which high temperature cooler can be, for example, a liquid/air heat exchanger, the liquid circuit of which is connected to the cooling circuit of an internal combustion engine of the vehicle. A low temperature cooler 12 is arranged in front of the high temperature cooler 11, which low temperature cooler can be, for example, a refrigerant/air heat exchanger. The low temperature cooler can be coupled thermally, for example, to an electric motor of the vehicle or power electronics of the vehicle, with heat from the electric motor or the power electronics being discharged via the refrigerant circuit to the low temperature cooler 12, and heat being discharged by said low temperature cooler 12 to the surroundings. A condenser 13 of a refrigerant circuit is arranged in front of the low temperature cooler 12.

[0042] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.