DE1294393B - Muffler for motor vehicles - Google Patents

Description

The invention relates to a muffler with a cylindrical Housing, at one end an exhaust gas inlet pipe and at the other end a Exhaust outlet pipe are attached, the exhaust gas inlet pipe over approximately the entire length of the housing protrudes into this and with a tangential passage opening is provided for the exhaust gases in a surrounding annular space, the wall of which is perforated and is surrounded by a further annular space filled with porous material.

In addition to the silencing in the mufflers on motor vehicles essentially the task of the still very hot exhaust gases emerging from the engine to clean, if necessary to detoxify and finally to cool down so far that they can no longer cause any harmful effects when leaking into the open air.

There are already numerous designs of various types of exhaust systems become known, all of which essentially consist of a housing in which Cross walls and layers are arranged so that the exhaust gases labyrinthine paths have to flow. Due to the multiple zigzag deflection, the gases in the generally perpendicularly hit transverse walls or impact surfaces, a jam occurs the exhaust gases in the muffler, which significantly reduces the performance of the engine. Additional noises occur due to the impact of the exhaust gas flow on the baffle walls which counteracts the main task of the exhaust system, noise reduction are directed.

The fact that the exhaust gases through in the known exhaust systems Pipelines, deflection channels, partition walls, etc. have to squeeze through, there is the There is a risk that residues from unburned parts will accumulate in undesired places and thereby increase the disadvantages explained above.

It has already become known a muffler in which the Silencer housing an adjoining room filled with porous material is switched on is into which the exhaust gas flow can enter through openings. That silencer is equipped with a cylindrical housing at one end of which an exhaust gas inlet pipe and at the other end of which an exhaust gas outlet pipe is attached, which over about the entire length of the housing protrudes into this and with a tangential passage opening is provided for the exhaust gases in a surrounding annulus, which is from another with porous material filled annular space is surrounded, the wall of the inner Annular space is perforated. The inlet tube, however, only has to be relatively at the two ends short nozzles through which the exhaust gases can pass. As a result of the great Exhaust gas, the speed in these nozzles must be extremely large, so that the two exhaust gas streams collide to achieve a turbulence. The exhaust gases then emerge in very complicated ways and leave the exhaust gas outlet pipe. The same disadvantages occur here as described above. It is coming added that the porous material in the annulus does not act as a mechanical filter can, since the exhaust gas flow does not flow through this space; rather, the perforated Wall only serve to counteract the resulting from the meeting of the partial flows Let pressure escape into the adjoining room. An exhaust system is also known with spark arrester for internal combustion engines, in which the glowing particles by centrifugal action the rotating exhaust gases are thrown off.

In another muffler for internal combustion engines occur Gases enter an expansion vessel through slit-shaped openings and collide with one another, so that the gas plate formed in the impact against the outlet end of a cylindrical or conical expansion vessel advances and over the edge of the tube in flows over in the opposite direction.

Another known muffler for internal combustion engines exists from a slotted tube, which lies in an outer tube, the flow cross-section between the two pipes from the inflow point gradually increases to itself then suddenly to narrow sharply and then to increase again, the gas being a carries out continuous rectified rotary movement around the longitudinal axis of the pot.

Furthermore, a silencer for internal combustion engines has become known, in which the exhaust gas flow in different gas flows with a helical progression Movement is divided, further dividing it into several gas streams of approximately the same Screw diameter and roughly the same thickness split exhaust gases with the same direction Movement move with different inclines, lag behind each other, overtake and penetrate.

Finally, there is a very complicated dual flow muffler arrangement has been proposed which consist of two symmetrically formed in a drum and housed muffler units with disposed at the ends of the drum Inlet channels and common outlet channel in the middle, each silencer unit a combination of a baffle connected to the inlet chamber, which the inflowing gas against the outer surface of the drum and there helically moved forward, and one or more chambers forming guide surfaces with the gas movement represents only insignificantly inhibiting breakthroughs.

The object of the invention is to create a muffler that was explained at the beginning To create kind that is not only geared towards good sound absorption, but which in addition, a significant reduction in power losses and above all also results in sufficient cleaning and detoxification of the exhaust gases.

The object is achieved according to the invention in that the Exhaust gas inlet pipe within the housing over its entire length, seen in cross section, as an open spiral with at least one turn and one that also extends over the entire length extending slot, is formed that both the exhaust gas inlet pipe as well as the wall of the inner annular space at its end face with a gas-tight one Plate is provided, and that the exhaust gas outlet pipe is connected to the outer annulus is.

In this way a flow of the exhaust gases is achieved, which initially finds time on the spiral flow path, chemically in the sense of post-combustion to react under the heat inherent in the exhaust gases, and then mechanically to be subjected to a filtering process. An advantageous embodiment the invention is achieved in that the exhaust gas inlet pipe is known per se Way is arranged eccentrically in the inner annulus that the slot is at its narrowest point.

A further advantageous embodiment of the invention is thereby achieved that the exhaust gas inlet pipe and the wall of the inner annular space in the direction are tapered to the exhaust outlet pipe.

Finally, it is also useful to reduce the flow conditions to improve that the exhaust gas inlet pipe several spiral turns with outwardly narrower increasing channel height.

In the drawing, embodiments of the invention are in the scheme shown, namely shows F i g. 1 shows a longitudinal section through the inventive Muffler, fig. 2 shows a cross section through this muffler according to FIG. 1 according to section line II-II, F i g. 3 shows a plan view of the muffler according to FIG G. 1 in the direction of arrow III, F i g. 4 shows a longitudinal section through another designed muffler, F i g. 5 with a cross section through a muffler eccentrically arranged exhaust gas inlet pipe, F i g. 6 shows a cross section through a Muffler with an exhaust gas inlet pipe with a spiral cross-section with several Turns and F i g. 7 shows a cross section through an exhaust gas inlet pipe, its channel height between the turns to narrow from the inside out.

The in the F i g. 1 to 3 shown muffler has a cylindrical housing 1, through one of which, expediently spherical, end face 1 a, the exhaust gas inlet pipe 2 is passed. The spherical cap 1 a is expediently welded tightly to the exhaust gas inlet pipe 2. The tube 2 has a longitudinal outlet slot 2 a, which according to FIG. 2 is designed so that the exhaust gases exit approximately tangentially over the entire length of the slot and a spiral movement according to the dash-dotted arrow in FIG. 2 run. The free space between the exhaust gas inlet pipe 2 and another surrounding pipe 3 is dimensioned so that an intense spiral movement of the exhaust gases can develop. The tube 3 is on the in F i g. 1, the left side shown is closed by an end disk 5, which can be connected to the tube 3 and to the housing 1 by welding. It goes without saying that the spherical cap 1 a does not have to consist of one piece with the cylindrical housing 1, but can be flanged, for example. Between the tube 3 and the housing 1 there is a cylindrical annular space which is filled with a heat-resistant filler layer 4, preferably made of glass wool.

After the vortex movement, the exhaust gases enter the filler layer preferably at the left end of the pipe 3 through numerous bores 3a and flow through it from left to right (FIG. 1) in an axially parallel direction, where they pass through slots or bores 6a in the end wall 6 can flow out. For easy replacement of the filler layer 4, the end wall 6 is screwed onto an end plate 2b of the exhaust gas inlet pipe 2 by means of a screw connection 2c. The spherical cap 7 absorbs the exhaust gases and directs them via a pipe socket 7 b to the adjoining exhaust gas outlet pipe. The easily exchangeable attachment of the spherical cap 7 takes place according to FIG. 1 and 3 expediently with the help of a pipe clamp 8 with clamping screw 8 c, which engages the pipe clamp lugs 8 a, 8 b in a manner known per se. After unscrewing the clamping screw 8c, the pipe clamp 8 can be removed so that the cap 7 can easily be pushed off to the right, and the end wall 6 unscrewed so that the filler layer 4 and all other parts of the muffler are accessible.

F i g. 4 shows a further advantageous embodiment of the invention. Here, the exhaust gas inlet pipe 9 is passed through an opening in the end face 12 and connected to it. In the interior of the housing 11 , the exhaust gas inlet pipe tapers so that an approximately trapezoidal longitudinal section results. The tube also has, as explained above, a longitudinal section 9 a; it is surrounded at a distance by a tube 10 , which is also trapezoidal in longitudinal section, the tapering of which is made in the sense of tube 9b, but somewhat stronger. In this case, it is expedient to provide the entire, or at least a larger part of the pipe surface over the circumference and viewed in the axial direction with gas outlet openings 10 a. The space between the pipe 10 and the housing 11 is in turn filled with a filler layer 15 , the cross section of which, however, widens more and more from left to right. A large annular surface of the end plate 15 is provided with gas passage openings 13a, this plate 13 also being fastened in a manner similar to that described above for the plate 6. This is in turn followed by a cap 14 with a gas outlet nozzle 14a.

In the advantageous embodiment according to FIG. 5, a perforated pipe 16 is in turn arranged within a housing 19 and an exhaust gas inlet pipe 17 with a spiral cross-section is arranged eccentrically in this. The eccentricity is denoted by the reference symbol 18. The gas outlet slot 17a is expediently directed in such a way that after exiting the slot the exhaust gases initially have a space which increases as a result of the eccentricity. A vortex movement can thus develop, after which the gases can, however, immediately exit to the outside through the holes in the tube 16, as described above.

F i g. 6 shows inside the housing 23 and the perforated tube 20 an exhaust gas inlet pipe 21 which has a plurality of spiral turns so that the gases inevitably guided in the direction of the dash-dotted arrow drawn will.

If it is desired that the pulsating pressure is reduced as continuously as possible to a uniformly high gas velocity, the exhaust gas inlet pipe 22 can, as shown in FIG. 7 are narrowed in such a spiral form from the inside to the outside that the channel height 22a, 22b, 22c becomes smaller and smaller. Strut-shaped reinforcements 24 can expediently be provided at individual points, which hold the individual windings together.

Claims (4)

Claims: 1. Muffler for motor vehicles with a cylindrical Housing having an exhaust gas inlet pipe at one end and an exhaust gas inlet pipe at the other end a Exhaust outlet pipe is attached, the exhaust gas inlet pipe over approximately the entire length of the housing protrudes into this and with a tangential passage opening is provided for the exhaust gases in a surrounding annular space, the wall of which is perforated and is surrounded by a further annular space filled with porous material, thereby characterized in that the exhaust gas inlet pipe (2) within the housing (1) via its whole length, seen in cross section, as an open spiral with at least one turn and a slot (2 a) also extending over the entire length is that both the exhaust gas inlet pipe (2) and the wall (3) of the inner annular space is provided on its end face with a gas-tight plate (2 b or 6), and that the exhaust gas outlet pipe (7, 7 b) is connected to the outer annular space (4). 2. Muffler according to claim 1, characterized in that the exhaust gas inlet pipe (17) arranged in a manner known per se in such an eccentric manner in the inner annular space is that the slot (17 a) is at its narrowest point. 3. Muffler according to claim 1 or 2, characterized in that the exhaust gas inlet pipe (9 b) and the wall (10) of the inner annular space is conical in the direction of the exhaust gas outlet pipe (14) are rejuvenated. 4. muffler according to one of the preceding claims, characterized in that that the exhaust gas inlet pipe (22) several spiral turns with outwardly narrowing Having channel height.