WO2001031179A1

WO2001031179A1 - Suction pipe with a drum controller

Info

Publication number: WO2001031179A1
Application number: PCT/EP2000/009976
Authority: WO
Inventors: Jürgen KOSICKI; Helmut Neuschwander
Original assignee: Filterwerk Mann+Hummel Gmbh
Priority date: 1999-10-23
Filing date: 2000-10-11
Publication date: 2001-05-03
Also published as: DE19951082B4; DE19951082A1

Abstract

The invention relates to a suction pipe, especially for the intake air of an internal combustion engine, which comprises a rotatably mounted drum controller for varying the suction channel length. Said drum controller (12) is received by bearing bushes (20) that are placed on the shaft ends (19a, 19b) and that are fixated in annular grooves (21). Said bearing bushes (20) are flexibly anchored in the suction pipe (15) by means of O rings (23). The shaft end (19b) projects from the interior of the suction pipe, thereby providing an interface (27) for a drive (26). The advantage of this arrangement is that the drive can be exchanged while it is not necessary to open the housing (28) of the drum controller, thereby preventing the interior of the suction pipe from being soiled when the drive is exchanged.

Description

Intake pipe with a shift drum

description

The invention relates to an intake manifold, in particular for the intake air of an internal combustion engine, in the housing of which a switching drum is provided for changing the length of the intake duct.

State of the art

Such suction pipes are known from the prior art, for example from DE 43 44 505 A1. According to this document, the shift drum used is installed in a longitudinal bore, which cuts the respectively shorter channels to the individual cylinders of an internal combustion engine. The short channels can be switched on or off by turning this shift drum. The shift drum is mounted in the intake manifold housing for this purpose. Needle and ball bearings are used here. However, this bearing technique poses problems in the practical use of the intake manifold. The combustion air, which is drawn through the individual suction channels, is strongly pressurized by pulsation. As a result, vibrations are also transmitted to the shift drum, which must be absorbed by the bearing. In order to be able to cope with this task, the needle bearings must be dimensioned accordingly, which disadvantageously increases the costs for the intake manifold. In addition, the vibrations are also transmitted to the intake manifold housing by the storage, which leads to increased structure-borne noise and also requires a stronger dimensioning of the intake manifold walls. This also results in additional costs or a higher component weight. Both reduce the economy of the proposed solution. In order to achieve a limited elastic storage of the shift drum, it is proposed according to EP 691 461 A1 to mount the shift drum overhung on one side. The shift drum can then be elastically supported via the radial sealing rings provided, which separate the suction channels from one another. As a result, however, these sealing rings are stressed more by the pressure pulsation, which impairs their function. In addition, the flying bearing principle on the side of the shift drum, where it has an interface to the drive, cannot be realized. Therefore, a roller bearing is provided at this point in the manner already described, which is placed in a cover, which also serves to close the installation opening for the shift drum. The bearing of the shift drum on the side of the roller bearing is thus still rigid, so that the disadvantage that vibrations can be transmitted to the housing due to the pressure pulsation of the intake air cannot be completely avoided.

The object of the invention is therefore to provide a suction tube with a shift drum which is easy to assemble, is inexpensive to manufacture and has a high level of reliability in operation. This object is achieved by the features of patent claim 1 and patent claim 3.

Advantages of the invention

According to the invention, the object is achieved in that the at least one sliding bushing which is provided for mounting the shift drum in the intake manifold housing has an elastic mounting fixture which corresponds to an annular groove in the shaft end. To make assembly easier, the bushing can be pushed onto the shaft end in the intake manifold before final assembly of the shift drum, whereby the assembly fixation engages. The mounting fixture can advantageously be formed by lugs that extend into the inner diameter of the bush. The assembly force of the bushes on the shaft end can be kept small by selecting the appropriate nose geometry. Since the mounting fixture is designed as part of the socket, additional components for fixing the socket are saved. In particular, for example, circlips can be omitted, which in addition to the socket on the Shaft ends would have to be installed and, in addition to increased assembly effort, would also result in an increase in the component weight.

The shift drum is provided for changing the length of the suction channel in the suction pipe. This change can be made continuously or in stages. Essentially two types of shift drums are used. In one case, the shift drum penetrates the shorter suction channels of two suction channels leading to the cylinder, so that they can be switched off by rotating the shift drum. In this case, the intake air takes the way through the longer suction channel. If the shift drum is opened, the intake air takes the path of lower resistance, i.e. through the shorter suction channel.

The other variant consists of a shift drum, which is wound in a spiral shape by the suction channels. By turning the shift drum, a through-hole moves, which connects the collecting space provided in the shift drum with the suction channels, so that the length of the suction channels changes.

An alternative embodiment of the slide bearing provides that the interface for driving the shift drum is provided on one of the shaft ends, this protruding from the bushing of the slide bearing. A drive can be provided at this interface. The advantageous slide bearings can also be used on the side of the shift drum, which must be equipped for the drive. This also eliminates the costly and heavy rolling bearing on this side. In addition, the bushings for the bearing of the shaft ends can be designed such that damping of the pressure pulsation on the shift drum can take place.

The damping properties of the plain bearing can be improved even more if the bushings are supported in the housing by an elastic ring. In particular, this can be an O-ring, which is pre-assembled in a mounting groove in the socket and via which the socket is mounted in the bearing receptacle in the intake manifold housing. This makes relative movements possible, which not only dampen the pressure purification, but are also able to compensate for tolerances that occur on the components. As a result, in particular the Switching roller occurring switching forces reduced, which means that cheaper drives can be used.

In addition to the radial bearing areas, the bushings can also have axial bearing areas according to an advantageous development of the invention. This enables the shift drum to be axially fixed without the bearing friction increasing significantly. Corresponding axial reference surfaces in the housing, which would have to be manufactured with increased demands on the component tolerances, are also unnecessary. The cutting roller can be fixed to the axial contact surfaces using axial pre-tensioning means, e.g. can consist of a coil spring. Of course, other spring elements, e.g. Disc springs, conceivable. The advantage of a fixation via elastic adjustment means is that defined axial forces can be exerted on the bearing of the shift drum. As a result, the friction forces that occur can be kept within defined limits, which simplifies the dimensioning of the drive.

According to an advantageous embodiment of the inventive concept, a deformation zone can be provided on the inner diameter of the bushing. By installing the bushing in the intake manifold, the diameter is reduced because the elastic receptacle exerts pressure on the bushing. This reduction in diameter can be absorbed by the deformation zone, so that this results in the necessary fit for easy adjustment of the shift drum. There is the advantage that soft materials, in particular plastic, can also be selected as the material for the bushing. These components can be manufactured inexpensively. In addition, a suitable pair of materials with favorable tribological properties can be found by appropriate choice of plastics.

A special embodiment of the invention results when the bushing is installed in a bearing cover, which at the same time serves to close a housing opening. In particular, it can be used to close an installation opening that is necessary for the assembly of the shift drum. This results in a unit that represents a sealed system in itself, while the shaft end of the shift drum with its interface to the drive can protrude from the cover. In the event that the drive needs to be replaced, the intake manifold itself cannot be opened. This has the advantage that the interior of the intake manifold cannot be contaminated by such a repair measure, which would reduce the functional reliability. Of course, the cover can also be provided on the side of the shift drum on which no drive is planned. No cover is then required on the interface side, and the corresponding shaft end can be pushed through an opening in the intake manifold housing. This opening can also serve to accommodate the socket. The advantage of this arrangement is the separation of the cover and drive functions, which results in a wider range of variations in the design of the intake manifolds. This can mean, for example, solving space problems in the installation space.

These and other features of preferred developments and inventions are apparent from the claims and also from the description and the drawings, the individual features being implemented individually or in groups in the form of subcombinations in the embodiment of the invention and in other areas, and can represent advantageous and protectable versions for which protection is claimed here.

drawing

Further details of the invention are described in the drawings using schematic exemplary embodiments.

Show here

1 shows the longitudinal section through a suction tube, the shift drum lying in the sectional plane (corresponds to section BB in FIG. 2),

Figure 2 shows a cross section through a suction pipe in a highly schematic representation according to section A - A in Figure 1 and Figure 3 shows a sliding bush with axial stop and lugs for fixing on the shaft end of the shift drum.

Description of the embodiments

In Figure 1, the longitudinal section through a suction pipe is shown, in which suction channels 10 a spiral around a collecting space 1 1. Only the first and last suction channel are shown. Short suction channels 10 b are penetrated by a switching drum 12, which can open or close them by rotation.

The combustion air flows through an inlet 13 into the collecting space 11. The way from there to outlets 14 can best be seen in FIG. From the plenum, the combustion air passes through the long suction channel 10 a or, depending on the position of the shift drum 12, through the short suction channel 10 b. The housing 15 of the intake manifold is attached to the internal combustion engine, not shown, via a cylinder head flange 16. The cylinder head flange is provided with the outlets 14 in order to ensure that the cylinders are supplied with combustion air.

The structure and installation of the shift drum 12 can best be seen in FIG. 1. The shift drum consists of a roller body 17 which is equipped with sealing rings 18 for sealing the suction channels 10 b from one another. In the roller body two shaft ends 19 a, 19 b are cast, on which the bushings 20 are fixed by snapping into annular grooves 21. The bushings 20 and the shaft ends 19 a, b result in plain bearings 22 a, b. These plain bearings are elastically fastened via O-rings 23 in the housing 15 or in a bearing cover 24. The O-rings are pre-assembled in the mounting grooves 25 in the sockets 20.

Due to the elastic mounting of the bushes 20 in the intake manifold, good results are achieved with regard to the damping of pressure pulsation vibrations of the intake air, which act directly on the shift drum 12. The vibrations are therefore less transmitted to the housing. An indicated drive 26 is also relieved. This makes it possible to use an electric motor for the drive. Here, for example, a structural unit is conceivable which, in addition to the electric motor, also contains a worm gear, wherein the shaft of the worm can be connected directly to an interface 27 of the shaft end 19b. Alternatively, the interface can be articulated by means of a vacuum box. An electromagnetic or hydraulic form of drive can also be selected.

The shift drum 12 must also be axially fixed in an installation space 28 of the suction tube. For this purpose, the bushings 20 have axial bearing areas 29, on which the shift drum is supported with end faces 30. The axial bearing areas are pressed against the end faces 30 by a helical spring 31. The helical spring 31 is supported on the one hand in a receptacle 32 and on the other hand on a contact surface 33 of the bush 20.

In order to achieve a complete seal of the housing 15 against the environment, the bearing cover 24 is provided with a sealing ring 34 towards the housing and with a shaft seal 35 to the shaft end 19 b carrying the interface 27.

FIG. 3 is a perspective illustration of the bushing 20. In particular, the axial bearing area 29, the contact surface 33, the mounting groove 25 and lugs 36, which serve to fix the bushing 20 in the annular groove 21 (see FIG. 1), can be seen.

Claims

claims

1. Intake pipe, in particular for the intake air of an internal combustion engine, which

- a housing (15) with an inlet (13) and cylinder-side outlets (14) for the combustion air,

- Suction channels (10a, b) which branch off from a collecting space (1 1) and

- A rotatably arranged shift drum (12) for changing the suction channel length, which is provided at at least one end with a shaft end (19a, b) for mounting in a slide bearing (22a, b), characterized in that the slide bearing consists of a bushing ( 20) with an elastic mounting fixture, which forms an interlocking connection with an annular groove (21) in the shaft end (19a, b).

2. Suction pipe according to claim 1, characterized in that the mounting fixture consists of lugs (36) which are arranged in the inner diameter of the socket (20).

3. Intake pipe, in particular for the intake air of an internal combustion engine, which

Suction channels (10a, b) which branch off from a collecting space (11),

- A rotatably arranged shift drum (12) for changing the suction channel length, which is provided with at least one end with a shaft end for mounting in a slide bearing (22b),

- An elastic receptacle for the slide bearing (22b) in the housing (15), characterized in that the slide bearing consists of a bush (20) through which the shaft end (19b) provided with an interface (27) for a drive (26) protrudes.

4. Suction pipe according to one of the preceding claims, characterized in that the switching drum (12) is installed in a cylindrical installation space (28) which penetrates shorter suction channels (10b) to the cylinders.

5. Intake pipe according to one of the preceding claims, characterized in that the bushing (20) has an axial bearing region (29) on which the shift drum is supported.

6. Suction pipe according to one of the preceding claims, characterized in that an elastic ring is provided as the elastic receptacle of the socket (20) in the housing (15), which is pre-assembled in a mounting groove (25) in the socket.

7. Suction pipe according to one of the preceding claims, characterized in that the inner diameter of the sleeve (20) has a deformation zone which allows a reduction in this diameter due to the pressure exerted by the elastic receptacle on the sleeve.

8. Intake pipe according to one of the preceding claims, characterized in that the elastic receptacle is installed in a bearing cover (24) which closes an opening in the housing (15).

9. Intake pipe according to one of the preceding claims, characterized in that the bush (20) has a contact surface (33) for an axial biasing means, in particular a helical spring (31).