SE1650338A1 - Sealing arrangement and seal for an air inlet pipe at an internal combustion engine - Google Patents

Abstract

A sealing arrangement (32) for an air inlet pipe (12) at an internal combustion engine comprises a recess (48) for a sealing ring and a sealing ring (39). The recess is formed at an end surface (29) of one of two interconnectable connectable flanges in a flange joint and extends around an air passage opening (52). The sealing ring (39) is provided with projections (59) adapted to be pressed into the recess (48) during assembly and is connected to a support member (38) with a through hole (40) corresponding to the flow area (41) of the air inlet pipe (12) and a number of mounting holes (42, 43) through which fastening means are adapted to extend to enable correct positioning of the sealing ring (39) in the recess (48). (Fig. 5)

Description

TECHNICAL FIELD The present invention relates to a sealing arrangement for an air inlet pipe to an internal combustion engine, a seal for a sealing arrangement and a vehicle comprising a sealing arrangement according to the appended claims.

BACKGROUND AND PRIOR ART Turbochargers in vehicles typically include a turbine driven by the exhaust gases of an internal combustion engine and a compressor that compresses air passed to the internal combustion engine to increase the fuel efficiency and power of the engine by forcing additional air into the engine combustion chamber. The internal combustion engine may also include an EGR system where exhaust gases are recirculated and mixed with the air intended to be supplied to the internal combustion engine. By mixing recirculated exhaust gases with air that is led to the combustion engine, the combustion temperature in the combustion chambers can be lowered and thus also the content of nitrogen oxides (NOX) that are formed during the combustion engine's combustion processes. To achieve the desired result, however, it is required that there is no leakage along the air inlet pipe between an air intake and the respective combustion chamber and / or along the pre-exhaust gas recirculation line. Such a leak can mean that the compressor compresses air which means that without exhaust gas mixing it cannot be used for improved combustion. This in turn can mean that noise occurs, poorer engine power, increased fuel consumption or poorer exhaust gas cleaning. If a leak occurs where a negative pressure prevails, e.g. inside the turbocharger, there is a risk that dirt can be sucked into the air inlet pipe and reach the internal combustion engine, which can cause engine damage.

It is known to connect an air inlet pipe with an exhaust gas recirculation line to an inlet manifold on the internal combustion engine with e.g. a för end joint at which a seal, e.g. an o-ring, is arranged to prevent leakage. The seal can be partially immersed in a guide groove. A problem with such arrangements is that it can be difficult to check whether the seal has ended up in the correct sealing position between the ends of the joints after the joints have been pressed against each other with screw joints or if the seal has slipped out of the guide groove and ended up in a position where the sealing ability is poorer. reassembly after a repair or the like because the end joint can be relatively difficult to access.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sealing arrangement and a seal for an air inlet pipe at an internal combustion engine, which sealing arrangement and seal ensures that the seal is kept in place in the correct position in connection with assembly. Another object is to provide a sealing arrangement and a seal which is easy to assemble. A further object is to provide a sealing arrangement and a seal which can be used together with conventional guide grooves for e.g. O-rings. These and other objects are achieved by the features set forth in the appended claims.

By utilizing the invention, the risk of leakage at an air inlet pipe in front of the internal combustion engine is reduced. This means that the air compressor compresses can be utilized for improved combustion in an efficient manner. The projections ensure that the sealing ring is in the correct position during an assembly process and the support means ensures that the sealing ring is not moved from the correct position when the fl ends of the fl end joint are pressed against each other.

In one embodiment the sealing ring is formed with radially outwardly directed projections and radially inwardly directed projections and in another embodiment the distance between two adjacent projections in the circumferential direction of the sealing ring is of a certain size. By doing so, the abutment surface between the sealing ring and the side walls of the recess is limited, which in turn limits the force needed to pressurize the sealing ring in the recess while the projections are still able to retain the sealing ring in the recess.

In one embodiment, the projections are arranged opposite each other, which ensures that the sealing ring presses equally against each side wall and does not bend in the recess.

In one embodiment the sealing ring has a substantially rectangular cross-sectional shape and in another embodiment the recess has a cross-sectional shape which substantially corresponds to the cross-sectional shape of the sealing ring. By making these, a wide sealing surface and a stability of the sealing ring are maintained which prevents it from rotating in the recess.

In one embodiment, the support member comprises two sides and a sealing part projecting from each side, which ensures that the sealing ring is compressed during assembly and fills the recess in a sealing-effective manner.

In one embodiment, at least two mounting holes are formed with an outwardly open slot which corresponds to a corresponding outwardly open slot in the end when the sealing ring is correctly mounted. The slots and fastening means make it easier to position the sealing ring relative to the recess during an assembly process and ensure that the sealing ring is mounted in the correct position and not moved from the correct position when the ends in the joint are pressed against each other.

Other features and advantages of the invention will be apparent from the claims, the description of exemplary embodiments and the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS In the following, embodiments of the invention are described by way of example with reference to the accompanying drawings, in which: Fig. 1 shows a vehicle with an internal combustion engine and an air intake.

Fig. 2 schematically shows an overcharged internal combustion engine with an EGR system whereby exhaust gases are recirculated and mixed with air which is intended to be supplied to the internal combustion engine.

Fig. 3 shows a connection between an air inlet pipe and an inlet manifold at an internal combustion engine.

Fig. 4 shows a perspective view of an air inlet pipe and an inlet manifold at a single-combustion engine and a sealing arrangement arranged therebetween according to an embodiment.

Fig. 5 shows a perspective view of an air inlet pipe with a sealing arrangement according to an embodiment.

Fig. 6 shows a seal with a sealing ring and a support member for a sealing arrangement according to an embodiment.

Fig. 7 shows a cross section through a seal with a sealing ring and a support member for a sealing arrangement according to an embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION Fig. 1 shows a motor vehicle 1 with a vehicle frame 2 at which a single-combustion engine 3 is arranged. An air intake 4 is arranged at an air duct 5 for supplying the internal combustion engine 3 with air. The motor vehicle 1 can be a heavy vehicle, e.g. a single truck or a bus or a lighter vehicle e.g. a car. Internal combustion engine 3 edge.ex. be a diesel engine or an Otto engine. In alternative embodiments, the internal combustion engine 3 may be intended for industrial or marine use, e.g. in a ship.

Fig. 2 schematically shows an overcharged internal combustion engine 3 with an EGR system 22 where exhaust gases are recirculated and mixed with air intended to be supplied to the internal combustion engine 3. By mixing recirculated exhaust gases with air passed to the internal combustion engine 3 the combustion temperature in the internal combustion engine nitrogen oxides (NOX) formed during the combustion processes of the internal combustion engine 3.

The combustion engine 3 in this example is a straight six-cylinder engine. Exhaust gases from the combustion engine 3 cylinders are led via an exhaust collector 6 and an exhaust line 7 to the turbine 8 in a turbocharger 9. The exhaust gases leaving the combustion engine 3 have an overpressure which results in them expanding through the turbine 8. The turbine 8 thereby receives a driving force transmitted via a connection compressor l0 the host turbocharger 9. The compressor l0 thereby compresses air which is sucked into an air inlet pipe l2 via the air intake 4, the air duct 5 (fig. 1) and an air filter ll. The compressed air in the air inlet pipe l2 is cooled in a charge air cooler l3 before it is fed to the internal combustion engine 3. An exhaust gas return line l4 extends between the exhaust line 7 and the air inlet pipe l2 to recirculate some of the exhaust gases in the exhaust line 7.

The return line 14 may comprise an EGR valve 15 with which it is possible to control the flow of exhaust gases through the return line 14. A control unit 16 may be adapted to control the EGR valve 15 by means of information on the current operating state of the combustion engine 3 so that a desired amount of exhaust gases is recirculated to combustion engine 3. The return line 14 may comprise an EGR cooler 17 in which the exhaust gases are cooled and a mixing device 18 which has the task of mixing the recirculated exhaust gases in the return line 14 with the air in the air inlet pipe 12. The mixing device 18 may be mounted on a first connection 19 between the return line 14 and the air inlet 12. After the recirculated exhaust gases have been mixed with compressed air in the air inlet pipe 12, the mixture is led via an inlet manifold 20 to the respective cylinders of the internal combustion engine 3. The air inlet pipe 12 can be connected to the inlet manifold 20 with a second connection 21. In an alternative embodiment without EGR system, the air inlet pipe 12 can extend from the charge air cooler 13 to the second connection 21 at the inlet branch pipe 20 without intermediate first connection 19.

Fig. 3 shows that the second joint 21 can be constituted by an end joint 25 with a first end 26 formed at a first element, in this example the inlet manifold 20 and a second flange 27 formed at a second element, in this example the air inlet pipe 12. The first joint 19 (Fig. 2) may be similarly formed with a first flange formed at a first element, in this example the exhaust return line 14 and a second fl evenly formed at the second element, in this example the air inlet pipe 12.

Fig. 4 shows that the first end face 26 has a first end surface 28 which is turned towards and adapted to abut against a corresponding second end surface 29 of the second end face 27 after assembly. The first end face 28 may be planar, as shown in the figure, while the second end face 29 may include a groove for a sealing ring, which will be described later. In the alternative embodiment, the second end surface 29 may be flat and the first end surface 28 comprise a groove for the sealing ring. A sealing arrangement 32 is arranged between the first flange 26 and the second end 27. The sealing arrangement 32 can be designed to be compressed to a sealing effect by the second end surface 29 being pressed against the first end surface 28 with a number of fastening means 33 e.g. in the form of screws 33 each adapted to extend through holes 34 in the second end 27 and into the corresponding holes 35 in the first end 26.

In Fig. 5 it is shown that the sealing arrangement 32 comprises a seal which comprises a support member 38 and a sealing ring 39. The support member 38 may be made of metal e.g. steel or of any other material suitable for the purpose, e.g. composite such as carbon fiber. The sealing ring 39 may be made of rubber or of some other elastically compressible material and may have a substantially rectangular cross-sectional shape. In alternative embodiments, the sealing ring 39 may have another cross-sectional shape, e.g. square, circular or oval. The support member 38 is formed with a through hole 40 corresponding to the flow area 41 of the air inlet pipe 12 and a number of through mounting holes 42, 43. The sealing ring 39 extends around the through hole 40 and is attached to the support member 38 in a suitable manner, e.g. by a casting process or by vulcanization. A screw 33 (Fig. 4) is adapted to extend through each of the mounting holes 42,43. To facilitate mounting of the air inlet pipe 12 at the inlet manifold 20 (Fig. 4), at least one but preferably two mounting holes 43 are carried by the support member 38 with an outwardly open slot 44 which is adapted to conform to a corresponding outwardly open slot 45 formed in the second sealing ring 27. 39 is correctly positioned. Two facing slots 44,45 are then adapted to receive a screw 33 (Fig. 4). During assembly, as shown in Fig. 4, two screws 33 are placed in the holes 35 in the first end 26, after which the air inlet pipe 12 is inserted into the counter inlet manifold 20 and the shaft of each screw 33 is inserted into the two opposite slots 44,45 (Fig. 5) resulting in that the sealing ring ends up in the correct position between the air inlet pipe 12 and the inlet manifold 20. Then screws 33 are placed in the other holes 34, 35, after which the air inlet pipe 12 is tightened against the inlet manifold 20.

Fig. 5 shows that the end surface 29 of the second end 27 is formed with an annular recess 48 for receiving the sealing ring 39. The recess 48 extends around an air passage opening 52 and is formed with a first contact surface 49 which is arranged to form a radial outer side wall in the recess. 48 and a second contact surface 50 which is arranged to form a radially inner side wall in the recess 48 and a third contact surface 51 which is arranged to form a bottom wall in the recess 48. The recess 48 may have a width corresponding to the desired width of the sealing ring 39. The recess 48 may be 3 - 6 mm wide and 3 - 6 mm deep but preferably 4.5 mm wide and 4 mm deep and can have a cross-sectional shape which substantially corresponds to the cross-sectional shape of the sealing ring 39.

Fig. 7 shows a cross section through the support member 38 and the sealing ring 39. The support member 38 comprises a first side 54 adapted to face one end surface 28,29 (Fig. 4), this example towards the flat first end surface 28 and a second side 55 adapted to face the second end face 28, 29 in this example the end face 29 (Fig. 5) in which the recess 48 is formed. The sealing ring 39 is arranged in the through-hole 40 and comprises a first sealing part 56 which extends from the front side 54 of the support member 38 and is adapted to be brought into sealing abutment against an end surface 28,29, in the example against the first end surface 28 (fig. 4) and a second sealing part 57 which extends from the other side 55 of the support member 38 and is adapted to be slid into the recess 48 (Fig. 5) during sealing for sealing abutment against the third contact surface 51 of the recess 48, i.e. against the bottom wall of the recess 48. In an advantageous embodiment, the first sealing part 56 in the unassembled state can extend from the first side 54 0.2 - 2 mm but preferably 0.5 mm. The second sealing part 57 can in an advantageous embodiment and in unassembled condition extend from the other side 55 2 - 10 mm by preferably 5 mm.

Fig. 6 shows that the sealing ring 39 is provided with a number of radially outwardly directed projections 58 which are adapted to abut against the first contact surface 49 in the recess 48 (Fig. 5) when the sealing ring 39 is mounted and a number of radially inwardly directed projections 59 which are adapted to abut against the second contact surface 50 in the recess 48 the sealing ring 39 is mounted to ensure that the seal is kept in place in the correct position in connection with mounting. The outwardly directed projections 58 and the inwardly directed projections 59 can be arranged opposite each other and the distance between two adjacent projections 58.59 in the circumferential direction of the sealing ring 39 can be 20-50 mm but preferably 35 mm.

The invention is not limited to the described embodiments, but a number of possibilities for modifications thereof are obvious to the person skilled in the art without this deviating from the basic idea of the invention as defined in the claims.

Claims (20)

A sealing arrangement for an air inlet pipe (12) at an internal combustion engine (3), which sealing arrangement (32) comprises a recess (48) for a sealing ring and a sealing ring (39) which recess is formed at an end surface (28, 29) of one of the two interconnectable connectors (26, 27) in an end joint (25) and extending around an air passage opening, characterized in that the sealing ring (39) is provided with projections (58, 59) adapted to be pressed into the recess (48) during assembly and that the sealing ring (39) is fixedly connected to a support member (38) by a through hole (40) corresponding to the flow area of the air inlet pipe (12) and a number of mounting holes (42, 43) through which fastening means (33) are adapted to allow correct positioning the sealing ring (39) in the recess (48). Sealing arrangement according to claim 1, characterized in that the sealing ring (39) is provided with a number of radially outwardly directed projections (58) which are adapted to abut a first contact surface (49) in the recess (48) and a number of radially inwardly directed projections (59) which are adapted to abut against a second contact surface (50) in the recess (48), to ensure that the sealing ring (39) is held in place in the correct position during assembly. Sealing arrangement according to Claim 2, characterized in that the outwardly directed projections (58) and the inwardly directed projections (59) are arranged opposite one another. Sealing arrangement according to Claim 2 or 3, characterized in that the distance between two adjacent projections (58.59) in the circumferential direction of the sealing ring (39) is 20-50 mm, preferably 35 mm. Sealing arrangement according to one of the preceding claims, characterized in that the sealing ring (39) has a substantially rectangular cross-sectional shape. Sealing arrangement according to one of the preceding claims, characterized in that the recess (48) has a cross-sectional shape which substantially corresponds to the cross-sectional shape of the sealing ring (39). Sealing arrangement according to any one of claims 1 to 6, characterized in that the support member (38) comprises a first side (54) and a second side (55) and that the sealing ring (39) comprises a first sealing part (56) extending away from the first side (54) sealing abutment against one end (26,27) and a second sealing member (57) extending away from the second side (55) for sealing abutment against the second flange (26,27). Sealing arrangement according to one of Claims 1 to 7, characterized in that at least two mounting holes (43) are formed with an outwardly open slot (44) which is adapted to correspond to a corresponding outwardly open slot (45) of a shaft (26, 27). when the sealing ring is correctly positioned in the recess (48). Sealing arrangement according to one of Claims 1 to 8, characterized in that the recess (48) is formed at an end connection (25) between the air inlet pipe (12) and an inlet manifold (20) at the internal combustion engine (3). Sealing arrangement according to one of Claims 1 to 8, characterized in that the recess (42) is formed at an end connection (25) between the air inlet pipe (12) and an exhaust gas return line (14) at the internal combustion engine (3). Sealing arrangement according to one of Claims 9 or 10, characterized in that the recess (48) is formed in the end surface (29) of an end (27) at the air inlet pipe (12). Sealing arrangement according to claim 11, characterized in that a recess is formed in the end surface (28) of an end (26) at the inlet manifold (20). Vehicle comprising a sealing arrangement according to any one of claims 1 - 12 A seal for a sealing arrangement (32) for an air inlet pipe (12) at an internal combustion engine (3), which seal comprises a support member (38) formed with a through hole (40) which is adapted to correspond to the flow area of the air inlet pipe (12) and one with the support member fixed connected sealing ring (39) extending around the through hole (40) and adapted to be provided at a recess (48) formed at an end surface (28, 29) of one of two interconnectable connectable ends (26, 27) in a flange joint (25), characterized in that the sealing ring (39) is provided with a number of projections (58, 59) adapted to be pressed into the recess (48) during assembly and that the support member (38) is formed with a number of mounting holes (42, 43). ) through which fastening means (33) are adapted to extend to enable the correct positioning of the sealing ring (39) in the recess (48). Seal according to Claim 14, characterized in that the sealing ring (39) is provided with a number of radially outwardly directed projections (58) and a number of radially inwardly directed projections (59). Seal according to Claim 15, characterized in that the outwardly directed projections (58) and the inwardly directed projections (59) are arranged opposite one another. 17. l7. Seal according to Claim 15 or 16, characterized in that the distance between two adjacent projections (58, 59) in the circumferential direction of the sealing ring (39) is 20-50 mm, preferably 35 mm. 18. l8. Seal according to one of Claims 14 to 17, characterized in that the sealing ring (39) has a substantially rectangular cross-sectional shape. 19. l9. Seal according to one of Claims 14 to 18, characterized in that the support means (38) comprises the first side (54) and a second side (55) and that the sealing ring (39) comprises a first sealing part (56) extending away from the first side (54). ) and a second sealing member (57) extending away from the other side (55). Seal according to one of Claims 14 to 18, characterized in that at least two mounting holes (43) are formed with an outwardly open slot (44) to facilitate mounting.