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(11) | EP 3 561 283 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | EXHAUST-GAS VALVE FOR AN EXHAUST-GAS CONTROL DEVICE |
| (57) An exhaust-gas valve (3) has two valve bodies (14, 15), which are manufactured in
one piece with a shaft (16), and two valve seats (12, 13), which are fastened to in
each case one insert (18, 19). The inserts (18, 19) have an interference fit (20),
and can be aligned relative to the valve bodies (14, 15) at a preassembly stage. The
sealing action of the exhaust-gas valve (3) is also tested at the preassembly stage.
After the preassembly stage, the inserts (18, 19) are welded to one another and are
pressed into a housing (11) of the exhaust-gas valve (3).
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[0001] The invention relates to an exhaust-gas valve for an exhaust-gas control device of an internal combustion engine, having a housing, having a first valve body for controlling the flow to a first outlet duct, and having a second valve body for controlling the flow to a second outlet duct, having a common shaft for holding the two valve bodies, having valve seats respectively facing the valve bodies, and having an actuating device for driving the shaft.
[0002] Exhaust-gas control devices are commonly used in modern motor vehicles for conducting exhaust gas of the internal combustion engine to a bypass duct, to a catalytic converter, to an exhaust-gas recirculation arrangement or to a turbocharger, and are known from practice. The exhaust-gas valve known from practice has a central inlet duct and two outlet ducts. The outlet ducts are controlled by the valve bodies. The shaft is displaced by an actuating device, and the position of the two valve bodies relative to the valve seats is thus controlled. The arrangement of the valve bodies of the exhaust-gas valve on a common shaft however requires very narrow tolerances, because each of the valves faces a dedicated valve seat. In the exhaust-gas valve known from practice, both valve bodies are fastened to the shaft so as to face valve seats which are fixedly arranged in the housing, which involves a high level of assembly effort.
[0003] The invention is based on the problem of further developing an exhaust-gas valve of the type mentioned in the introduction such that it is particularly easy to assemble.
[0004] Said problem is solved according to the invention in that the two valve bodies are formed as a prefabricated unit with the shaft.
[0005] By means of this design, the assembly of the valve bodies within the housing is avoided, because the prefabricated unit composed of valve bodies and shaft can be inserted into the housing. There is therefore no need for welded connections to be made within the housing, which is normally poorly accessible. The positioning of the valve bodies on the shaft in relation to the positions of the valve seats is furthermore particularly straightforward. The exhaust-gas valve can thus be assembled in a particularly simple manner.
[0006] In another advantageous refinement of the invention, the positioning of the valve bodies in the exhaust-gas valve is particularly exact if the shaft and the valve bodies are manufactured in one piece. Owing to the unipartite form, the shaft and valve bodies can for example be manufactured as a turned part. In this way, exact parallelism of disk-shaped valve bodies with respect to one another is furthermore ensured.
[0007] In another advantageous refinement of the invention, tilting of the shaft can be easily avoided if the shaft has a guide on the end averted from the actuating device.
[0008] In another advantageous refinement of the invention, it is conducive to a further simplification of the assembly of the exhaust-gas valve if the guide is arranged on a support element which is supported in the housing. In a case which is particularly simple in terms of construction, the support element is formed as a disk.
[0009] In another advantageous refinement of the invention, it is conducive to a further simplification of the assembly of the exhaust-gas valve if the support element is pressed into the housing.
[0010] In another advantageous refinement of the invention, the exhaust-gas valve is particularly compact if the support element is arranged in one of the outlet ducts and has dimensions for the throughflow of exhaust gas. In this way, the support element requires no separate structural space.
[0011] In another advantageous refinement of the invention, the valve seats can be positioned in the housing in a highly exact manner if the valve seats are arranged on inserts fastened in the housing, and if the inserts bear against one another. By virtue of the inserts being designed so as to bear against one another, an exact spacing of the two valve seats is furthermore ensured. The exhaust-gas valve thus has a reliable sealing action.
[0012] In another advantageous refinement of the invention, the exhaust-gas valve exhibits particularly high stability if the inserts of the valve seats are cohesively connected to one another. Furthermore, during the assembly process, the valve seats can firstly be aligned relative to the two valve bodies fastened to the shaft. Since the valve bodies already have a fixed spacing to one another owing to the unit with the shaft, the positions of the valve seats relative to the valve bodies are permanently fixed as a result of the welding of the inserts.
[0013] In another advantageous refinement of the invention, the valve seats can be easily aligned relative to one another at a preassembly stage if the inserts are connected to one another by means of an interference fit. The interference fit permits the alignment of the valve seats with the valve bodies manufactured as a unit with the shaft. The valve seats can be easily set to the valve bodies outside the housing, allow the sealing action to be tested, and can in particular be permanently fixed as a result of welding of the inserts.
[0014] In another advantageous refinement of the invention, it is conducive to a further simplification of the assembly of the exhaust-gas valve if the inserts are inserted into the housing from the side of the actuating device. The actuating device is preferably formed as a housing cover of the housing.
[0015] The invention permits numerous embodiments. To further illustrate its basic principle, one of these embodiments is illustrated in the drawing and will be described below. In the drawing:
- figure 1
- schematically shows an exhaust-gas control device of an internal combustion engine with an exhaust-gas valve,
- figure 2
- shows components of the exhaust-gas valve from figure 1 in the closed state on an enlarged scale and in a sectional illustration,
- figure 3
- shows a support element of the exhaust-gas valve from figure 1 before the assembly process, on an enlarged scale and in a side view,
- figure 4
- shows the support element from figure 3 in a further view,
- figure 5
- shows a partial region of two inserts of the exhaust-gas valve on a greatly enlarged scale.
[0016] Figure 1 schematically shows an internal combustion engine 1 with an exhaust-gas control device 2 and an exhaust-gas valve 3. An internal combustion engine 1 has an exhaust-gas pipe 4 and an intake duct 5. An inlet duct 6 of the exhaust-gas valve 3 is connected to the exhaust-gas pipe 4. The exhaust-gas valve 3 has two outlet ducts 7, 8, via which partial streams of the exhaust gas of the internal combustion engine 1 are supplied to two schematically illustrated devices 9, 10. The devices 9, 10 may be a turbocharger, a bypass duct, an exhaust-gas recirculation arrangement or the like.
[0017] The exhaust-gas valve 3 has a housing 11 with two valve seats 12, 13 fastened therein. Two valve bodies 14, 15 face the valve seats 12, 13. The valve bodies 14, 15 are arranged on a common shaft 16. The shaft 16 can be displaced by an actuating device 17, and the valve bodies 14, 15 can thus be adjusted relative to the valve seats 12, 13. The actuating device 17 is formed as a housing cover of the housing 11. The valve bodies 14, 15 have different cross sections. The valve seat 13 situated closest to the actuating device 17 has a larger cross section than the valve seat 12 remote from the actuating device 17.
[0018] Figure 2 shows the exhaust-gas valve 3 from figure 1 in an enlarged sectional illustration. The shaft 16 is manufactured in one piece with the two valve bodies 14, 15 as a turned part. The valve seats 12, 13 are arranged in each case on an insert 18, 19. The inserts 18, 19 are welded to one another and are furthermore pressed into the housing 11. For the assembly process, the inserts 18, 19 can be preassembled, and aligned with the valve seats 12, 13 relative to the valve bodies 14, 15, outside the housing 11. Furthermore, the sealing action of the valve bodies 14, 15 against the valve seats 12, 13 can be tested outside the housing 11. During the preassembly stage, an interference fit 20 holds the two inserts 18, 19 in their position until they are permanently fixed to one another by welding. The inserts 18, 19 with the valve seats 12, 13 can subsequently be pressed into the housing 11 from the side of the actuating device 17. On the side averted from the actuating device 17, the shaft 16 has a support element 21. The support element 21 is of disk-shaped form and has a guide 22 for the free end of the shaft 16.
[0019] Figure 3 shows, in an enlarged illustration of the support element 21 from a side elevation, that said support element has recesses 23 for the throughflow of the exhaust gas. For illustrative purposes, figure 4 illustrates the support element 21 in a position rotated in relation to figure 3. It can be seen here that the support element 21 has, on its ends, claws 24 for the fastening in the housing 11 illustrated in figure 2.
1. An exhaust-gas valve (3) for an exhaust-gas control device (2) of an internal combustion
engine (1), having a housing (11), having a first valve body (14) for controlling
the flow to a first outlet duct (7), and having a second valve body (15) for controlling
the flow to a second outlet duct (8), having a common shaft (16) for holding the two
valve bodies (14, 15), having valve seats (12, 13) respectively facing the valve bodies
(14, 15), and having an actuating device (17) for driving the shaft (16), characterized in that the two valve bodies (14, 15) are formed as a prefabricated unit with the shaft (16).
2. The exhaust-gas valve as claimed in claim 1, characterized in that the shaft (16) and the valve bodies (14, 15) are manufactured in one piece.
3. The exhaust-gas valve as claimed in claim 1 or 2, characterized in that the shaft (16) has a guide (22) on the end averted from the actuating device (17).
4. The exhaust-gas valve as claimed in claim 3, characterized in that the guide (22) is arranged on a support element (21) which is supported in the housing
(11) .
5. The exhaust-gas valve as claimed in claim 4, characterized in that the support element (21) is pressed into the housing (11).
6. The exhaust-gas valve as claimed in claim 4 or 5, characterized in that the support element (21) is arranged in one of the outlet ducts (7) and has dimensions
for the throughflow of exhaust gas.
7. The exhaust-gas valve as claimed in at least one of claims 1 to 6, characterized in that the valve seats (12, 13) are arranged on inserts (18, 19) fastened in the housing
(11), and in that the inserts (18, 19) bear against one another.
8. The exhaust-gas valve as claimed in claim 7, characterized in that the inserts (18, 19) of the valve seats (12, 13) are cohesively connected to one
another.
9. The exhaust-gas valve as claimed in claim 7 or 8, characterized in that the inserts (18, 19) are connected to one another by means of an interference fit
(20).
10. The exhaust-gas valve as claimed in at least one of claims 7 to 9, characterized in that the inserts (18, 19) are inserted into the housing (11) from the side of the actuating
device (17).