CN215370007U

CN215370007U - Screw connection device for fastening an exhaust manifold to a cylinder head and multi-cylinder internal combustion engine

Info

Publication number: CN215370007U
Application number: CN202022238725.8U
Authority: CN
Inventors: 托马斯·绍佩; 米夏埃尔·梅森; 奇普里安·伊万·德内茨
Original assignee: FEV Europe GmbH
Current assignee: FEV Europe GmbH
Priority date: 2019-10-10
Filing date: 2020-10-10
Publication date: 2021-12-31
Anticipated expiration: 2030-10-10
Also published as: DE102020005936A1

Abstract

The utility model relates to a screw connection device for fastening an exhaust manifold (40) to a cylinder head (10), wherein a first screw fastening device is provided on a first side of an exhaust gas duct (15). Here, a clamping plate (50) is arranged on a second side of the exhaust channel (15) and a second screw fastening means (30) of the clamping plate (50) is accessible from the first side. The utility model also relates to a multi-cylinder internal combustion engine.

Description

Screw connection device for fastening an exhaust manifold to a cylinder head and multi-cylinder internal combustion engine

Technical Field

The utility model relates to a screw connection device for fastening an exhaust manifold to a cylinder head and to an internal combustion engine having a corresponding screw connection device.

Background

Even if the utility model can be used for internal combustion engines of any size, a construction form is preferably considered which is relatively large and in which more than just one cylinder head is used. For example, one cylinder head can be used for each cylinder. A plurality of cylinders can also share a common cylinder head. Thus, for example, in an eight cylinder engine, four cylinder heads can be used. Such an engine can be used in a relatively large vehicle such as a relatively large truck, an earth moving machine, a crane, or the like, or in a marine diesel engine. In such engines, different or separate cylinder heads are used, so that in the case of maintenance, when maintenance should be carried out at one cylinder, only the respective cylinder head needs to be removed. A further advantage is that in the case of the separate construction type, the overall weight of the cylinder head is correspondingly low, which in turn makes mounting or dismounting easier for the fitter. Another major advantage is the reduction of temperature (or also load) related material stresses. I.e. the rate of heating up of components such as the engine block, the cylinder head and the inlet channel and the exhaust manifold can be different at engine start-up, and can also have different coefficients of thermal expansion and various material stresses may occur in an engine with a one-piece cylinder head. Usually, the exhaust manifold is screwed to the cylinder head by means of, for example, 4 bolts. Here, two bolts are located at the upper part and are therefore easy to reach, while the other two bolts are located at the lower part and are therefore difficult to reach. Furthermore, it is known from DE000004205454a1, DE102008029020A and WO002015088397 to be able to fasten using a tensioning device such as a clamping plate.

SUMMERY OF THE UTILITY MODEL

The object of the present invention is to provide a new connection of an exhaust manifold to a cylinder head, which is easy to open and close. The connection of these components should preferably also be optimized as follows: the thermally induced dimensional changes are well absorbed and no impermissible stresses are built up. The preferred solution should be able to be used optimally in particular under the spatial conditions of larger engines.

Said object is achieved by means of the screwing device according to the utility model. Preferred modifications are also described in the present invention.

The screw fastening means for fastening the exhaust manifold with the cylinder head includes a first screw fastening means provided on a first side of the exhaust passage. The clamping plate is arranged on the second side of the exhaust channel and the screw fastening means of the clamping plate are accessible from the first side. The second side is in particular the side opposite the first side with respect to the exhaust duct. The first side is in particular the upper or accessible side, while the second side is the side which, viewed from above, is located behind or below the exhaust gas duct. With the described construction it is possible to simply disassemble the exhaust manifold and the cylinder head for maintenance purposes, since it is not necessary to loosen bolts which are difficult to reach, for example, from below.

The screw connection for fastening the exhaust manifold to the cylinder head can also be provided with two screw connections, namely a first screw connection and a second screw connection, which have at least proportionally opposite tensioning directions. This results in a floating bearing which is able to better absorb or dissipate the forces which occur when the components to be screwed heat up to different extents.

Accordingly, there is preferably a floating connection such that an increase in the connection force of one of the threaded fastening means tends to cause an increase in the connection force of the other threaded fastening means. The term "tend" means in particular: there is a tendency or tendency, even if this can be the case: the increase mentioned is also maintained in the case of the increase mentioned, for example, since no corresponding increase in the static friction occurs.

In particular, alternatively, a stop can be provided for at least one of the screw fastening devices, which stop limits or prevents an increase in the coupling force of the other screw fastening device when the coupling force of one of the screw fastening devices increases. Simplified mounting can thus be achieved.

Alternatively or additionally, a centering region, such as in particular at least one centering surface, can be provided for visual or form-fitting positional orientation of the exhaust manifold relative to the cylinder head, wherein this is advantageous in particular in the case of floating bearings, since otherwise the positioning of the component to be screwed may become more difficult. The centering region can include bores oriented with respect to one another. It is also possible to use at least one face, preferably two faces, said faces preferably making an acute angle of more than 45 ° with respect to the contact plane of the parts to be screwed. Preferably, in the case of an exhaust manifold, a maximum of two centering regions can be used on all cylinders in total, which centering regions are preferably arranged on cylinders which are as far away from one another as possible. The centering region is determined or oriented such that no hyperstatic occurs, as it causes internal stresses. Thus, the centering region may be centered, for example, in the x and y directions, while a second centering region distant in the x direction may be centered in the y direction.

It is furthermore advantageous if the clamping plate comprises a wedge-shaped contact region and the first threaded fastening means exert a clamping force on this region. By means of the first threaded fastening means, it is thus also achieved: the component is tensioned on the underside, so that a sufficient contact pressure is also generated here from the cylinder head to the exhaust manifold.

In particular, the clamping plate has its tightening region in the central position and from there on one side a contact or clamping region with the cylinder head, while on the side opposite it there is a contact or clamping region with the exhaust manifold. A see-saw-like element is thus provided, which is tensioned centrally via the bolt and presses the screwed elements toward one another like an arch.

In particular in the case of an internal combustion engine having a plurality of cylinders, a clamping plate can be provided for each of the cylinders. At least two clamping plates are then connected to one another by means of a coupling element. This is advantageous because the clamping plate is not permanently or non-releasably connected to the cylinder head and to the exhaust manifold, but in this case only the mentioned screw connection of the coupling piece has to be disconnected in order to remove the cylinder head and/or the exhaust manifold. In order that in this state the clamping plates do not fall off and must be positioned in a complex manner in the region which is difficult to access during the renewed fastening, the clamping plate is preferably fastened to the adjacent clamping plate via a coupling. In this case, it is advantageous if the coupling parts can be easily elastically and/or plastically deformable or at least comprise elastically and/or plastically deformable regions in order to compensate for an orientation and/or an angular deviation of the clamping plates from one another.

Drawings

Preferred embodiments are described below by way of example with reference to the accompanying drawings. The figures show:

fig. 1 shows an exploded view of a section of a cylinder head 10 and an exhaust manifold 40;

fig. 2 shows a plan view of an assembly with a section of the cylinder head 10 and the exhaust manifold 40;

fig. 3 shows a side sectional view through the threaded fastening device in a first embodiment;

fig. 4 shows a detail of the embodiment of fig. 3;

fig. 5 shows a side sectional view through a second embodiment of a threaded fastening device;

FIG. 6 shows a top view of the splint 50;

FIG. 7 shows a side cross-sectional view of the splint of FIG. 6;

FIG. 8 shows a perspective view illustrating the centering area;

FIG. 9 shows a cross-sectional view through the centering region of FIG. 8;

FIG. 10 shows an assembly with two cleats 50;

FIG. 11 shows a perspective view of an internal combustion engine; and

fig. 12 shows a variant in the region of the

centering region

14, 44.

Detailed Description

Fig. 1 shows a cylinder head 10 which is provided with a flange via which it can be connected with an exhaust manifold 40. For this purpose, the flange of the cylinder head 10 and the flange of the exhaust manifold 40 each have a flat surface which can be connected to one another via a seal 15 located therebetween and can be permanently connected by means of a threaded fastening device described below and shown in fig. 2 and 3. The flat surfaces mentioned preferably have no centering or positioning shoulders or edges in the contact region. During screwing, in the exhaust manifoldTwo first threaded fastening means 20 are provided on the upper side of the tube 40, which fasten said exhaust manifold to the cylinder head 10. Said first threaded fastening means (see fig. 3) make an angle β of 35 ° with the connection plane. In a preferred embodiment, the angle is between 20 ° and 50 °. Thus, with the illustrated tightening force F of the first threaded fastening device 20, a force F is generated in the force triangle which is perpendicular to the contact plane of the two components as a pressing force_pAnd a lateral force F in the connection plane perpendicular thereto_s. The mentioned upper side of the exhaust manifold is the side which is located at the upper part when it is installed or is easily accessible to the fitter. Fig. 1 shows an exhaust gas duct 45 which starts in the cylinder head 10 at a respective outlet valve (not shown) and conducts the exhaust gas into a respective region of the exhaust manifold 40, where it converges with the respective exhaust gas duct of the other cylinder and leads, for example, to an exhaust gas treatment device. Thus, the term "exhaust passage 45" refers to the interior region of the cylinder head 10 and of the exhaust manifold 40. A clamping plate 50 is arranged on the side of the exhaust duct 45 opposite the upper side, which is also referred to below as the lower side. Said clamping plate 50 is an arcuate component which is fastened to the cylinder head 10 by means of the second threaded fastening means 30 and comprises a free end which surrounds one end of the flange of the exhaust manifold 40, wherein contact between these two components is produced on the clamping surface 51. Preferably, the clamping surface 51 is at an angle α of 30 ° with respect to the mentioned contact plane. For this purpose, the exhaust manifold 40 has corresponding clamping surfaces on its flange. In an advantageous embodiment, the angle α can lie between 20 ° and 60 °. The orientation of the angle β of the first threaded fastening means 20 is directed such that the lateral force F is_sThe exhaust manifold 40 or more precisely its flange is pressed into said clamping surface 51. Thus, the force F is neglected in the case of frictional forces_sActing there, the force causes, via a change in direction along the angle α of the clamping surface 51, a force pressing the flange against the cylinder head 10 there. Because this produces a contact pressure on two opposite sides of the exhaust duct 45 and in each case in front of the exhaust duct in the longitudinal direction of the engineThe first and second

screw fastening devices

20 and 30 mentioned are then provided, so that a pressing force of the two components is induced around four points, which in combination with the sealing element 15 causes a sealing. The contact pressure of the exhaust manifold 40 with the cylinder head 10 can be determined by means of at least the first or the second screw fastening 20 or 30 or preferably the first and the second screw fastening.

For the purpose of illustrating the clamping plate 50, it is shown enlarged in fig. 4. The second threaded fastening means 30 pull said clamping plate 50 with its central zone towards the cylinder head 10. Two arms project oppositely from the central region. One arm terminates in a bearing surface 56 for supporting the clamp plate relative to the cylinder head 10, while the other arm comprises the mentioned clamping surface 51. Assuming substantially equal arm lengths, the reaction force is thus directed along said lateral force F_sActs on the clamping surface 51, said reaction force corresponding approximately to half the pulling force of the second threaded fastening means 30 and thereby generating a clamping force at this location. In the sectional plane shown, the lateral stop of the bearing surface 56 is not visible, which ensures that the clamping plate 50 does not move laterally, which would cause shearing forces acting on the second threaded fastening means 30. In an alternative embodiment, as shown in fig. 10, the bearing surfaces can be placed at an angle opposite to the angle α, so that a lateral displacement of the clamping plate 50 is prevented and a lateral stop is not required. In addition to the first threaded fastening device 20 shown, a contact-surface contact pressure can also be generated by the second threaded fastening device 30, in that: the screwing force is increased there, which causes a force acting in the pressing direction via the angle α of the clamping surface.

Then, to a small extent, the relative position of the head 40 with respect to the head 10 (transversely to the clamping surface) is not precisely determined, but can be slightly varied by varying the tensioning paths of the first and second threaded fastening means 20 and 30. This can then be seen as a floating bearing. In order to precisely orient the two components during installation, according to fig. 8 and 9, centering

areas

14 and 44 are provided on the cylinder head 10 and on the exhaust manifold 40, respectively. During installation, it is to be noted that the centering regions, which are embodied as bores, are flush with one another. Alternatively, a flush orientation can be achieved by means of a pin which is introduced during installation and which can preferably be removed after tightening of the first and second threaded fastening means 20 and 30.

One advantage of the mentioned floating bearing is that dimensional changes of the cylinder head 10 and of the exhaust manifold 40 can be received better and with less displacement. It is precisely at the start of the engine and during the phases of different engine loads, i.e. at the mentioned components, that different temperatures can occur. This can be partially compensated for by cooling means provided in the cylinder head 10 and/or the exhaust manifold 40. In contrast to the prior art, such as DE 4205454a1 or DE102008029020a 1, in which the region resembling the clamping surface is a one-piece component of the cylinder head, the following advantages result from the current two-piece design with clamping plates and the certain elasticity due to the length of the second threaded fastening means 30: temperature expansions of the different components can be absorbed or conducted away more easily.

Mounting the exhaust manifold 40 to the cylinder head 10 can be performed as follows: first, the components are oriented relative to one another and the first and second threaded fastening means 20 and 30 are screwed in without significant torque transmission so that the centering

regions

14 and 44, as mentioned, are oriented relative to one another. Subsequently, the first and second

screw fastening devices

20 and 30 are tightened at a prescribed torque. Here, the static friction between the cylinder head 10 and the exhaust manifold 40 ensures: the components are not displaced from each other. Subsequently, a bolt locking device, for example a form-fitting locking device, ensures that the bolt does not loosen during operation. This can be done, for example, by a crown nut/cotter pin connection or a locking tab.

Fig. 5 shows an alternative to the screw connection, in which (in contrast to fig. 3 or 4) no distance is produced between the clamping plate 50 and the cylinder head 10 in the region of the screw connection. But here a stop 52 is produced which simply ensures that the desired position of the clamping plate 50 can be set simply. During installation, the clamping plate is first fastened with a predetermined desired force by means of the second threaded fastening means 30 (two bolts) and the assembly is then connected to the exhaust manifold 40 via the first threaded fastening means 20.

As mentioned above, it is advantageous to reach the first and second threaded fastening means 20 and 30 from above. The head of the first threaded fastening means 30 does not necessarily have to be located on the upper side itself, but can also be arranged below, if it is easily accessible, for example, via a socket head wrench. If one of the engine's cylinder heads 10 should be removed, said first and second threaded fastening means 20 and 30 and the connection from the cylinder head to the engine block (not shown) are loosened. The clamp plate 50 is then originally free and will fall into the engine cavity. I.e. for each cylinder, a separate clamp plate 50 is used. To prevent this, the clamping plates of adjacent cylinders are connected via a coupling 55, as this is shown in fig. 10 and 11. The coupling 55 is a connecting member connected to at least two clamping plates 50. For a clamping plate 50 which is not screwed by means of the second threaded fastening means 30, the coupling provides a certain dimensional stability in order to prevent the clamping plate from falling into the engine compartment in this state, and thus to ensure that the corresponding second threaded fastening means 30 easily acquires a matching thread when it is tightened again. However, the coupling 45 is also sufficiently flexible so that the positional tolerance or thermal expansion or vibration of the clamping plate 50 can be easily absorbed. To this end, the coupling according to fig. 10 comprises slits which reduce the tensile strength or torsional rigidity. In particular, the slits allow plastic deformation of the coupling piece 45. This makes it possible to easily remove and reinstall the cylinder head without having to remove the associated exhaust manifold.

Fig. 12 shows a variant of the centering

region

14, 44. An additional threaded fastening means 47 is used here. The screwing direction can be perpendicular to the connection plane of the exhaust manifold 40 and the cylinder head 10. The additional threaded fastening means 47 can be used to orient the mentioned

components

10, 40 with respect to each other. For this purpose, a close fit with respect to a (for example cylindrical) section of the additional threaded fastening device 47 can be provided in the centering region 44 of the exhaust manifold 40. As already described above, the first threaded fastening means 20 of each cylinder preferably comprises in principle two bolts. Alternatively, in this embodiment, for example, one of the two screws can be replaced by an additional threaded fastening device 47. Alternatively, the first threaded fastening means 20 can also be omitted entirely. Optionally, the additional screw fastening can comprise an expansion compensator 48, which has a certain elasticity and thus always ensures a sufficient contact pressure of the screwed

components

10, 40. The mounting is advantageously carried out such that the additional threaded fastening means 47 are first locked and then the first and second threaded fastening means 20 and 30 are locked.

Functional reversal is possible and is encompassed by the inventive concept as follows: the cylinder head and the exhaust manifold are interchanged. Then, for example, the second threaded fastening means 30 will pass through the exhaust manifold and the clamping surface 51 of the clamping plate will come into contact with the flange of the cylinder head. The term "above" as used above is applicable in the case of an engine typically mounted in a corresponding working apparatus, such as a (preferably larger) internal combustion engine.

Claims

1. A screw-on device for fastening an exhaust manifold (40) to a cylinder head (10), having a first and a second screw-on device (20, 30),

it is characterized in that the preparation method is characterized in that,

the first and second threaded fastening means (20, 30) having at least partially opposite tensioning directions,

the first threaded fastening means (20) being provided on a first side of an exhaust gas channel (45) and fastening the exhaust manifold (40) on the cylinder head (10) by means of the first threaded fastening means (20), and

a clamping plate (50) is arranged on a second side of the exhaust gas duct (45), said clamping plate being fastened to the cylinder head (10) by means of the second screw fastening means (30) and the second screw fastening means (30) being accessible from the first side.

2. A screwing device according to claim 1, wherein the screwing device is a floating coupling such that an increase in the coupling force of one of the first and second threaded fastening devices (20, 30) tends to cause an increase in the coupling force of the other threaded fastening device.

3. Screwing device according to claim 1 or 2, wherein for at least one of said first and second threaded fastening means (20, 30) a stop (52) is provided, which limits or prevents the increase of the connection force of one of said first and second threaded fastening means (20, 30) when the connection force of the other threaded fastening means increases.

4. Screwing device according to claim 1 or 2, characterized in that it comprises a centering area (14, 44) for visual or positive position orientation of the exhaust manifold (40) with respect to the head (10).

5. A screwing device according to claim 4, characterized in that said centering area (14, 44) is at least one centering surface.

6. A screwing device according to claim 1 or 2, characterized in that said clamping plate (50) comprises a wedge-shaped contact zone and in that said first threaded fastening means (20) exerts a clamping force on said contact zone.

7. Screwing device according to claim 1 or 2, characterised in that said clamping plate (50) has its screwing region in a central position and, starting therefrom, a contact or clamping region with said cylinder head (10) on one side and a contact or clamping region with said exhaust manifold (40) on the side opposite to this side.

8. A multi-cylinder internal combustion engine having a screw joint arrangement according to any one of the preceding claims for each cylinder, characterized in that the two clamping plates (50) of the different cylinders are connected by means of a coupling piece (55).

9. A multi-cylinder internal combustion engine according to claim 8, wherein the coupling members (55) are or comprise elastically and/or plastically deformable areas in order to compensate for orientation and/or angular deviations of the clamping plates (50) from each other.