DE1084081B - Exhaust engine braking device for four-stroke internal combustion engines with exhaust gas turbocharging - Google Patents

Description

The invention relates to an exhaust braking device for four-stroke internal combustion engines with exhaust gas turbocharging and with at least two of the cylinder outlet openings depending on the number of cylinders Turbine leading exhaust lines that can be shut off in front of the turbine. For the operation of such exhaust gas turbines the kinetic energy of the exhaust gas flow is essentially used. It is therefore intended to reduce of energy losses, the volume of the exhaust line upstream of the turbine must be as small as possible and depending on the number of cylinders and the firing order, two or more exhaust pipes must be provided so that the exhaust flows from the cylinders to the turbine do not interfere with each other. A good The effect of an exhaust brake, on the other hand, requires the largest possible volume of the receiving space the shut-off device of the exhaust line, to which the exhaust gas flows from as many cylinders as possible are fed should. It is namely a high exhaust back pressure is required for a strong braking effect, the only can be achieved through the cooperation of as many cylinders as possible with a large intake volume. An expansion of the intake volume by relocating the shut-off devices of the exhaust line behind the turbine is practically impracticable because the turbine lights cannot withstand the high pressure and oil losses occur. The demands for extensive utilization of the energy of the exhaust gases by the exhaust gas turbines are exactly the opposite of those used for a good braking effect Conditions.

The aim of the invention is to provide a simple exhaust braking device which is free from impairment the turbine power gives a strong braking effect.

The invention consists essentially in the fact that the during turbine operation to accommodate the Exhaust gases for each exhaust stroke available space in front of the exhaust openings for the braking process through connection the exhaust lines can be enlarged with one another or with an additional chamber. Therefore the overall arrangement required to achieve a high turbine output is retained, nevertheless but a significantly increased braking effect compared to the known designs is achieved, because the receiving volume is increased during braking, so cylinders in a common barely push out and thus the prerequisites for achieving a high and even exhaust back pressure are fulfilled. Each exhaust line can have its own and tailored to the required volume additional chamber may be provided. However, it is cheaper to have a common additional chamber to arrange for the individual exhaust lines, exhaust engine braking device

for four-stroke internal combustion engines

with exhaust gas turbocharging

Applicant:

Steyr-Daimler-Puch Aktiengesellschaft,
Steyr (Austria)

Representative: Dipl.-Ing. F. Schnell, patent attorney,
Ingolstadt / Danube, Feselenstr. 52

Claimed priority:
Austria from May 22, 1958

Dipl.-Ing. Gerhard Götz and Dipl.-Ing. Hans Tomala,

Steyr (Austria),
have been named as inventors

so that these are connected to one another via the chamber. Because of the mostly very cramped conditions in motor vehicles Installation conditions, however, is the direct connection between the exhaust lines most expedient, especially since there is also a significant reduction in construction costs. At the immediate Connection of the exhaust lines will increase the intake space sufficiently achieved because for each exhaust process the volume of both or all exhaust lines for pressure storage is available, whereas so far only one exhaust line has served as a pick-up space.

In a further embodiment of the invention, there is a closable connection opening between the exhaust lines provided, wherein the closure member of the connection opening od by a linkage. Like. is coupled to the shut-off devices of the exhaust lines in such a way that it is when the shut-off devices are open assumes its closed position, so that the separation of the exhaust lines in normal driving and their connection is guaranteed during braking. The exhaust lines are directly adjacent to one another and the closable connection opening in the partition wall does not noticeably increase the size of the harmful space with it.

In order to achieve the same length of paths for the gas streams to the common receiving space as possible, this is according to the invention the connection opening approximately in the

009 547/120

Arranged in the middle of the cylinder bank. A particularly simple and practical construction results, if the closure or shut-off elements of the connection opening and the exhaust lines are on parallel axes mounted flaps are formed, which open when the connection opening is closed or open Exhaust lines lie in parallel planes.

In multi-cylinder, slot-controlled two-stroke internal combustion engines with exhaust gas turbocharging, it is already known that the exhaust pipe supports two cylinders each, whose ignition distance is not less than 90 °, to be connected by a cross line and in the connecting line a throttle valve or the like to be provided. By this measure, the before Turbine inlet resulting pressure mountain through the exhaust line back via the connecting line in a nozzle with low pressure and into the turbine or turbine chamber downstream of the nozzle migrate, whereby the subsidence of the pressure mountain accelerates and at the same time those present in the exhaust gases Energy is better used. With the well-known facility, it becomes a completely different one Purpose sought and achieved. It is also known in internal combustion engines with multiple exhaust lines to provide shut-off devices in the latter, which are designed as flaps mounted on parallel axes and in their different positions lie in parallel planes. Here, however, there is neither exhaust gas turbocharging an exhaust engine braking device is also provided, and the flaps in the exhaust pipes serve only to adjust the clearance of the exhaust pipes depending on the respective To change the flow rate in order to influence the scavenging from the exhaust side.

In the drawing, the subject matter of the invention is shown, for example, namely shows

Fig. 1 shows the part of an exhaust system in front of the exhaust gas turbine schematically in the diagram, and

Fig. 2 is a cross-section along the line H-II of Fig. 1 on a larger scale.

With 1, 2, 3 and 4 the exhaust ports of the four cylinders of a four-stroke internal combustion engine are designated, a common exhaust line 5 for the outlet openings 1 and 4 and a common exhaust line for the outlet openings 2 and 3 a common exhaust line 6 are provided. In the two exhaust lines 5 and 6 an exhaust flap 7 and 8 is arranged just in front of the exhaust gas turbine (not shown). With 9 is a connection opening between the two exhaust lines arranged approximately in the middle of the cylinder row 5 and 6, which can be closed by a flap 10. The flaps 7 and 8 are each in the open position when the flap 10 is closed and vice versa. the Flaps 7 and 8 and the flap 10 are coupled to one another by a linkage 11 and become common actuated. It can be seen that the axes 12, 13 and 14 of the flaps 7, 8 and 10 are arranged in parallel are and that these flaps are in parallel planes during normal driving.

Claims (4)

Patent claims: 1. Exhaust engine braking device for four-stroke internal combustion engines with exhaust gas turbocharging and, depending on the number of cylinders, at least two leading from the cylinder outlet openings to the turbine Exhaust lines with exhaust openings that can be shut off in front of the turbine for engine braking, characterized in that the during turbine operation for receiving the exhaust gases space available in front of the exhaust openings for the braking process for each exhaust cycle Connection of the exhaust lines (5, 6) with one another or with an additional chamber can be enlarged is. 2. Device according to claim 1, characterized in that that between the exhaust lines (5, 6) a closable connection opening (9) is provided, wherein the closure organ (10) of the connection opening by a linkage (11) Od. Like. Is coupled to the shut-off devices (7, 8) of the exhaust lines in such a way that it is open when Shut-off elements (7, 8) is in its closed position. 3. Device according to claim 2, characterized in that the connecting opening (9) approximately in the middle between the cylinder outlet openings (1, 4) of the first and last cylinder is arranged in a row, so that the gas flows are of approximately the same length during engine braking operation Paths from the cylinder outlet openings (1 to 4) to the common receiving space (5, 6) result. 4. Device according to claim 2 or 3, characterized in that the closure or shut-off elements the connection opening (9) and the exhaust lines (5, 6) as mounted on parallel axes Flaps (10, 7, 8) are formed, which when the connection opening is closed or open Exhaust lines lie in parallel planes. Considered publications:
German Auslegeschrift No. 1 004 861;
U.S. Patent No. 2,717,583. 1 sheet of drawings © 009 547/120 6.60