GB2340087A

GB2340087A - Vehicle body

Info

Publication number: GB2340087A
Application number: GB9917632A
Authority: GB
Inventors: Matthias Ehm; Gunter Siegel
Original assignee: DaimlerChrysler AG
Current assignee: Mercedes Benz Group AG
Priority date: 1998-07-29
Filing date: 1999-07-27
Publication date: 2000-02-16
Anticipated expiration: 2019-07-27
Also published as: DE19834131C2; FR2781725A1; ITRM990475A1; DE19834131A1; GB9917632D0; IT1309122B1; ITRM990475A0; GB2340087B

Description

2340087 Vehicle Body The invention relates to a vehicle body having a

front wall which partitions a passenger compartment from an engine compartment, closable by a bonnet, and together with a windscreen limits the passenger compartment at the front, having a plenum chamber which is sealed off from the engine compartment in front of the front wall and is limited at the top by a section of the bonnet having an air passage port and by a water collection channel beginning at the windscreen, and having a fan accommodated in the plenum chamber for the ventilation of the passenger compartment, which aspirates fresh air from the plenum chamber through a filter apparatus.

In a known motor vehicle, having an engine compartment and a passenger compartment (DE 196 32 714 Al), a plenum chamber extends from the region of a closed bonnet sufficiently far downwards to form a double-walled separation between passenger compartment and engine compartment and hence a separate dividing space. In the plenum chamber, designed as an installed module, components of a heating and ventilation or air conditioning system, especially fan, heat exchanger, condenser, pollen filter and/or appropriate air ducts, are arranged. Some of these components, especially the ventilation ducts, are installed in an equipment module connected to the plenum chamber module and connected to each other via appropriate connecting apertures in the two modules.

In a known vehicle body (DE 43 13 783 Cl), a trough-shaped fresh air duct, beginning at the air intake port in the bonnet, is suspended below the bonnet and fresh air is fed thereto from the top of the bonnet through the air passage port. The fresh air flowing into the fresh air duct is guided to the fresh air transition region of the fresh air duct, with precipitation of water, and there makes a transition into a duct mounted in front of the front wall which extends over the entire width of the equipment space or plenum chamber mounted in front of the front wall. The duct is composed of a lower bowl and an upper bowl, from which the water catchment channel is shaped. The channel ends in the region of the centrally arranged windscreen wiper unit, where the water runs away to the lower bowl. The lower bowl is provided with an aperture below the windscreen wiper unit, through which the water present passes into a furaiel-shaped ran-off. An additional channel is also formed on the lower bowl, receiving leakage water passing between the upper bowl and the windscreen and passing it to the aperture in the lower bowl connected to the run-off. The lower bowl has an air outlet port which rests flush on a front wall 2 aperture in the front wall and is connected via a filter device to the intake system of a fan. The filter device and the fan, in this arrangement, are arranged beyond the front wall in the vehicle interior.

In a vehicle body of the type referred to initially, provision has already been made (198 11 189.4-42) for the filter device to be accommodated in the plenum chamber. The filter device possesses a dust filter or an odour filter, e.g. an active charcoal filter, or what is known as a combination filter which is received in a filter housing. The filter housing is designed so that the air intake lies on the side of the filter housing facing away from the bonnet with the air intake port and is covered by the horizontally arranged filter. As a result, first the filter is protected against moisture penetrating through the air intake port, and secondly there is a bottom-to-top flow through the filter. As a result of its flow resistance, the filter causes uniform distribution of the air flow at the air intake of the filter housing, so that water drops contained in the fresh air are not entrained by local speed peaks at the air intake of the filter housing but precipitate on the bottom of the equipment space or plenum chamber.

The present invention seeks, in a vehicle body of the type referred to initially, to enlarge the space available in the vehicle interior by further reduction of the installed space requirement for the ventilation and/or air conditioning of the vehicle interior.

According to the present invention there is provided a vehicle body having a front wall which partitions a passenger compartment from an engine compartment, closable by a bonnet, and together with a windscreen limits the passenger compartment at the front, having a plenum chamber which is sealed off from the engine compartment in front of the front wall and is limited at the top by a section of the bonnet having an air passage port and by a water collection channel beginning at -the windscreen, and having a fan accommodated in the plenum chamber for the ventilation of the passenger compartment, which aspirates fresh air from the plenum chamber through a filter apparatus, wherein fan and filter apparatus are combined to form a ventilation module, a filter housing, receiving at least one air filter and having an air passage port arranged on the underside facing away from the bonnet and a removable filter lid covering the filter being attached to the axial air intake of a fan housing which is connected by an outlet connector, enclosing a tangential air outlet, to a wall aperture in the front wall.

3 The invention also provides vehicle body having a front wall which partitions a passenger compartment from an engine compartment, closable by a bonnet, and together with a windscreen limits the passenger compartment at the front, having a plenum chamber which is sealed off from the engine compartment in front of the front wall and is limited at the top by a section of the bonnet having an air passage port and by a water collection channel beginning at the windscreen, and having a fan accommodated in the plenum chamber for the ventilation of the passenger compartment, which aspirates fresh air from the plenum chamber through a filter apparatus, wherein the fan and the filter apparatus are combined to form a ventilation module, two filter boxes, each receiving at least one filter and each provided with an air intake port and an air outlet port on both end faces of a fan housing having an axial air intake and tangential air outlet enclosed by an outlet connector being attached on the fan housing and rotatable thereon so that their air outlet ports are coaxial with the air intake of the fan housing and the fan housing is attached by its outlet connector to a wall aperture in the front wall.

The vehicle body according to the invention has the advantage that, as a result of the combination of fan and filter apparatus to form a ventilation module, the filter apparatus and fan are available as an extremely compact installed unit which can readily be accommodated in a non-bulky plenum chamber of the vehicle body and can very easily be removed in order to change the filter. As a result of the space-saving design of the plenum chamber thus achieved, the space available for the vehicle interior can be increased. The arrangement and fixing of the module comprising the fan and filter apparatus in the plenum chamber permits a significantly quieter ventilation and/or air conditioning of the vehicle interior. Also, the vibrations of the fan motor are not transmitted to the body and the steering. By opening the bonnet, the ventilation module and hence the filter apparatus, which contains a dust filter'or combination filter and can optionally be additionally fitted with an odour filter, become freely accessible so that the filter can be changed quickly, simply and conveniently.

Advantageous embodiments of the vehicle body according to the invention, with expedient designs and developments of the invention, are apparent from the additional claims.

According to an advantageous embodiment of the invention, a plateshaped dust filter covering the air intake port and an odour filter designed as a body of revolution are arranged within the filter housing one behind the other in the direction of 4 air flow, so that the body of revolution lies coaxially to the air intake of the fan housing and its axis is aligned approximately at right angles to the normal of the plate of the dust filter. According to alternative embodiments of the invention, the body of revolution may be designed as a hollow cylinder or as a paraboloid which is generated by the rotation of a parabola about an axis of rotation running through its apex.

If the body of revolution is designed as a hollow cylinder, its external surface is open to radial flow and its clear interior space covers the air intake of the fan housing, a bypass valve which can be pivoted into two end pivot positions being arranged at the end of the interior space of the hollow cylinder remote from the air intake of the fan housing so that it completely masks the clear cross section of the interior space of the hollow cylinder in one of its end pivot positions and exposes it to the maximum in its other end pivot position. With the bypass valve closed, the odour filter is active, flow passing through the external surface of the hollow cylinder from outside to inside, while with the bypass valve open the air flows, circumventing the odour filter, directly through the interior space of the hollow cylinder to the fan housing, since the minimum pressure loss is obtained by this path.

If the body of revolution is designed as a paraboloid, its external surface is open to flow and its circular aperture covers the air intake of the fan housing. With this design of the odour filter, the bypass valve is lacking, so that the filter always remains in the air flow path, but in this case the contact surface of the filter is about 45% greater than when the odour filter is designed as a hollow cylinder, because in this case the space not taken up by the absent bypass valve can be fully used for the filter surface.

According to another embodiment of the invention, only one filter is provided in the filter housing and is designed as a plate-shaped dust or combination filter covering the air intake port. In the region between the filter end and the air intake of the fan housing, the filter housing and filter lid are designed so that they form a circular swirl duct. In this swirl duct the air, excited by the blade wheel of the fan, is caused to rotate, which results in the fan being well filled with air. As a result the power requirement of the fan motor falls. A similar generation of turbulence to that produced by the swirl duct is achieved in the examples of embodiment referred to above with the odour filter designed as a body of revolution.

According to an advantageous embodiment of the invention, the filter housing has an air induction connector placed over a ftirther front wall aperture, referred to as the air circulation port, which air induction connector, viewed in the direction of air flow, opens in the filter housing behind the filter covering the air intake port. A hemispherical air circulation valve, which is associated with the air induction connector, is arranged in the filter housing to be pivotable into two end pivot positions so that the opening of the air induction connector is completely masked in one of its end pivot positions and completely exposed in its other end pivot position. The spherical shape of the air circulation valve acts to assist the generation of the air turbulence previously mentioned in front of the air intake of the fan housing, doing so by supplying the fan with filtered fresh air and also with circulating air aspirated through the air-circulation port in the front wall from the vehicle interior, if, according to a further embodiment of the invention, the arrangement of the hemispherical air circulation valve is such that it completely blocks the flow path from the plate-shaped filter to the fan in its end pivot position, in other words blocks the supply of fresh air, exposing the opening of the air induction connector and completely exposes it in its end pivot position masking the opening of the air induction connector.

According to a further advantageous embodiment of the invention, the fan has a fan housing with an axial air intake and a tangential air outlet enclosed by an outlet connector and the filter apparatus has two filter housings each receiving at least one filter and each having an air intake port and an air outlet port. The two filter boxes are attached on both sides of the fan housing and rotatable thereon so that their air outlet ports are coaxial with the axial air intakes of the fan housing. The fan housing is in turn attached by its outlet connector to a wall aperture in the front wall, to which an air conditioning box or an air distribution system in the vehicle interior is connected. As a result of a symmetrical structure with two identical filter boxes, the ventilation or installed module is extremely compact and has a 35% smaller installed volume than conventional fan and filter apparatuses. Since the two filter boxes are rotatably fixed by appropriate fixing members to the fan housing, variations of structural shape are possible within the module, so that the module can be adapted to the structural space available within the plenum chamber and installation clashes with adjoining components and units can be circumvented. The module can thus be used unchanged in a great many different vehicle models.

According to another advantageous embodiment of the invention, a plateshaped dust filter and a hollow cylindrical odour filter, e.g. an active charcoal filter, are 6 arranged one behind the other, viewed in the airflow direction, in each filter box. On the end face of the odour filter facing the dust filter, a bypass valve is arranged to be pivotable into two end pivot positions so that it completely masks the clear interior space of the hollow cylindrical odour filter in one of its end pivot positions and exposes it to the maximum in its other end pivot position. When the bypass valve is closed, flow takes place through the external surface of the odour filter from outside to inside, and after opening of the bypass valve the air flows directly into the fan with a greatly reduced pressure loss.

According to a further embodiment of the invention, within each hollow cylindrical odour filter, a quarter of the cylinder shell is cut away and replaced by a housing wall in the shape of a quarter of an arc of a circle. An air induction connector formed in each case on the filter housing and connected to an air circulation port in the front wall opens in the region of the cut-away portion. An air circulation valve is arTanged in each case at the opening of the air induction connector to be pivotable into two end pivot positions so that the clear cross section of the opening is completely masked in one end pivot position and exposed to the maximum in the other end pivot position. The cutaway portion in the hollow cylindrical odour filter or the incompletely closed hollow cylindrical odour filter permits the air circulation valve to pivot into the assigned filter, which results in a shortening of the overall structural length of the module. To right and left of the fan, either fresh air can be aspirated via the fresh air valves installed in front of the dust filters or circulating air can be aspirated via the opened circulating air valves, can pass through the odour filter or, circumventing the odour filter, can flow to the fan. To the right and left of the fan, however, the fresh air can also be combined independently with the circulating air and the mixed air passed via the odour filter or directly to the fan depending on the position of the bypass valves.

The invention is described in detail below with reference to embodiments of the invention shown in the drawing, in which:

Fig. I shows part of a perspective view of a vehicle body in the front structural region with front wall, windscreen and plenum chamber and of a ventilation module inserted in the plenum chamber, Fig. 2 shows a perspective view of the ventilation module according to Fig. I with the filter lid taken off, 7 Fig. 3 shows a perspective view of the ventilation module with the filter lid taken off and the filters removed, Fig. 4 shows a perspective view of the fan housing of the ventilation module remaining after removal of the filter housing, Fig. 5 shows part of a longitudinal section of the vehicle body in the front structural region according to the line of section V-V in Fig. 1, Fig. 6 shows a section along the line VINI in Fig. 5, Fig. 7 shows a section along the line VII-VU in Fig. 5, Fig. 8 shows a section along the line VHI-VHI in Fig. 1, Figs. 9 each show the same view as in Figs. 6 and 7 and 10 with a modified odour filter, Figs. 11 each show the same view as in Figs. 6 and 7 and 12 with a modified filter housing, Fig. 13 shows a longitudinal section through a ventilation module according to a further embodiment, pictured diagrammatically, Fig. 14 shows a cross section of the ventilation module according to Fig. 13, pictured diagrammatically, Fig. 15 shows a front view of the ventilation module according to Figs. 13 and 14, Fig. 16 shows a plan view of the ventilation module according to Fig. 15, Fig. 17 shows a lateral view of the ventilation module according to Fig. 15, Fig. 18 shows a cross section through the ventilation module along the line of section XVHI-XVHI in Fig. 14 with the bypass valve opened, pictured diagrammatically, Fig. 19 shows the same view as in Fig. 18 with the bypass valve closed, and Fig. 20 shows the same view as in Fig. 13 of a third embodiment of the ventilation module.

In a vehicle body of a private car shown in longitudinal section in Fig. 5, a vehicle interior or passenger compartment I I and an engine compartment 12 are shown which are partitioned from one another by a front wall 13. In this arrangement, the front wall 13 extends, starting from a crossmember 14, downwards to the A vehicle body floor 10, while above the crossmember 14 the passenger compartment 11 is limited at the front by a windscreen 15 extending as far as the crossmember 14. The engine compartment 12, receiving an engine which is not shown here, is closed at the top by a bonnet 16 which has a transverse air passage port 17. The air passage port 17, masked by a flush-fitting 8 grill 18, serves to aspirate fresh air through a ventilation module 20 in order to supply air to an air conditioning box 19 of an air conditioning unit integrated in the passenger compartment 11. With a different finish of the passenger compartment 11, a heating box or merely an air distributor may be provided instead of the air conditioning box 19.

The ventilation module 20 is arranged in a plenum chamber 21 formed in front of the front wall 13 and sealed off from the engine compartment 12, and supplied at its lowest point with run-off spouts to remove water entering into the plenum chamber 21 via the air passage port 17, these spouts being designed, for example, as non-return valves and positioned at the lowest point of the plenum chamber. The run-off spouts are not shown in Fig. 5. The plenum chamber 21 serves as a water and air collection space and, at the same time, as an equipment space for receiving various items of equipment, e.g. the windscreen wiper unit 22. In addition, however, boxes with instrumentation electronics, fuse boxes, servo-braking aids and the like can also be accommodated in the plenum chamber.

In the ventilation module 20, which is shown in various stages of assembly in Figs. I to 4, a fan 23 and a filter apparatus 24 are structurally combined. In this arrangement, the ventilation module 20 forms an extremely compact installed unit which can easily be accommodated in the plenum chamber 21 without clashing for space with the equipment present there. In Fig. 1, the windscreen wiper unit 22, diagrammatically illustrated in Fig. 5, which sits above the ventilation module 20 is omitted for the sake of clarity, only the wiper linkage 25 with the two wiper arms 26 and 27 being shown. The fan 23 has a fan housing 28 with an axial air intake 29 (Figs. 3 and 4) and a tangential air outlet 31 enclosed by an outlet connector 30. The filter apparatus 24 has a filter housing 32 with an air intake port 33 arranged on the underside, facing away from the bonnet 12 (Figs. 3 and 7), and a removable filter lid 34 covering the' filter housing 32. The filter housing 32 with filter lid 34 is attached to the air intake 29 of the fan housing 28, and the fan housing 28 is fixed by its outlet connector 30 to a wall aperture 35 in the front wall 13 (Fig. 5). Two air filters are received in the filter housing 32, specifically a plate-shaped dust filter 36 and an odour filter 37 designed as a hollow cylinder which may, for example, be an active charcoal filter. The plate-shaped dust filter 36 completely covers the air intake port 33 of the filter housing 32, while the odour filter 37, arranged behind the dust filter 36 viewed in the direction of air flow, is arranged coaxial to the air intake 29 and encloses the air intake 29 with one of its end faces. The axis of the odour filter 37, 9 in this arrangement, is oriented at right angles to the normal of the plate-shaped dust filter 36. Also formed on the filter housing 32 is an air induction connector 38 for aspirating circulating air from the passenger compartment 11 and opening, viewed in the direction of air flow, behind the dust filter 36 in the filter housing 32. As is not visible here, the air induction connector 38 is placed on a further wall aperture in the front wall 13, completely covering that aperture, which is arranged parallel to and at a distance from the wall aperture 35 covered by the outlet connector 30 of the fan housing 28. While, as shown in Fig. 5, the air conditioning box 19 of the air conditioning unit is attached to the wall aperture 35 and, in a known manner, possesses an evaporator 40, a heat exchanger 41 and numerous air distribution valves 42, the wall aperture covered by the air induction connector 38 is left free, as what is known as an air circulation port, so that air from the passenger compartment I I can flow through. Arranged at the opening 39 on the housing side of the air induction connector 38 within the filter housing 32 is a circulating air filter 43 or filter screen.

In order to illustrate the construction of the ventilation module 30, various components of the module 20, shown completely in Fig. 1, are removed in Figs. 2 to 4. In Fig. 2, only the filter lid 34 has been taken away, so that the filters 36, 37 and 43 can be changed. In Fig. 3, the said filters have been removed, so that the air intake port 33, otherwise covered by the plate-shaped dust filter 36, the opening 39 of the air induction connector 38, covered by the circulating air filter 43, and the air intake 29 of the fan housing 28 can be clearly seen. In Fig. 4, the filter housing 32 with filter lid 34 is completely removed and only the fan 23 remains. The air intake 29 and the outlet connector 30 of the fan housing 28 enclosing the air outlet can be clearly seen. The fan wheel 45 of the fan 23, identifiable in the sectional illustration of Fig. 5, is driven by an electric motor 44. For rapid filter exchange, the filter lid'34 is clipped onto the filter housing 32, as is identifiable in the sectional view of Fig. 8.

For metering of the fresh air aspirated from the plenum chamber 21 and the circulating air aspirated from the passenger compartment 11, a bypass valve 46 and an air circulation valve 47 are provided in the ventilation module 20, specifically in the region of the filter apparatus 24, and can be identified in the sectional illustrations of Figs. 6 and 7. The bypass valve 46, of two-bladed design, is arranged on the end face of the hollow cylindrical odour filter 37 remote from the air intake 29 of the fan housing 28. It is pivotable between two end pivot positions, completely masking the clear cross section of the interior space of the hollow cylinder of the odour filter 37 in one of its end pivot positions (Fig. 7) and exposing it to the maximum in its other end pivot position (Fig. 6). With the bypass valve 46 closed, the fresh air coming from the air intake port 33 or - with the air circulation valve 47 opened - the circulating air flowing in via the induction connector 3 8 flows through the hollow cylindrical odour filter 3 7 radially, from outside to inside, and passes via the air intake 29 into the fan housing 28. With the bypass valve 46 opened (Fig. 6) the fresh or circulating air flows directly through the interior space of the odour filter 37 into the air intake 29 of the fan housing 28.

The air circulation valve 47 assigned to the opening 39 of the air induction connector 38 is of hemispherical design and likewise pivotable between two end pivot positions. In the end pivot position shown in Figs. 6 and 7, the air circulation valve 47 completely covers the opening 39 of the air induction connector 38, so that the circulating air is cut off and only fresh air - as symbolized by the air-flow arrows drawn in - is aspirated via the dust filter 36 from the plenum chamber 21. If the air circulation valve 47 is moved over into its other end pivot position, it pivots upwards through 90 in Fig. 7 and so exposes the opening 39 of the air induction connector 38, while it simultaneously shuts off the flow path from the dust filter 36 to the odour filter 37. In this case, only circulating air is aspirated, passing, depending on the position of the bypass valve 46, through the odour filter 37 or, circumventing the odour filter 37, into the air intake 29 of the fan housing 28.

In the case of the modified ventilation module 20 shown in Figs. 9 and 10, in the same sectional illustration as in Figs. 6 and 7, only the shape of the odour filter 37' has been modified by comparison with the ventilation module 20 described above and the bypass valve has been omitted. Otherwise, the module 20 is unchanged, so that identical components bear identical reference numbers. The odour filter 37' is again designed as a body of revolution, though not as a hollow cylinder but as a paraboloid, the body shape of which is generated by rotating a parabola about an axis of rotation passing through its apex. The circular aperture of the paraboloid covers the air intake 29 and the fresh or circulating air flows through the shell of the paraboloid from outside to inside. As a result of the fact that the structural space for the absent bypass valve is taken up by the odour filter 37, the contact surface of the odour filter 37' is approximately 45% larger than in the case of the hollow cylindrical odour filter 37 in Figs. 6 and 7.

In the ventilation module 20 shown in the same sectional illustrations in Figs. I I and 12 the separate odour filter is omitted and only the plateshaped dust filter 36, which can also be replaced by a combination filter, likewise plate-shaped, is present. The filter housing 32 and filter lid 34 are formed in the region between the filter end of the dust filter 36, in other words the opening 39 of the air induction connector 38, and the air intake 29 of the fan housing 28 as a circular swirl duct 48. As in the case of the bodyof-revolution shape of the odour filters 37 and 37' in the examples of embodiment given in Figs. 6 and 7, or 9 and 10, the air flowing through the filter apparatus 24, excited by the fan wheel 45, is caused to rotate in the circular swirl duct 48, as a result of which the fan 23 is well filled with air and, as a result, the necessary power requirement of this electric motor 44 falls. Otherwise, the structure and action of the fan module 20 are the same as for the fan module 20 described in connection with Figs. I to 8, so that identical components are given identical reference numbers.

The ventilation module 20' shown in various sectional illustrations in Figs. 13 and 14 and in various views in Figs. 15 to 17 is notable for a symmetrical structure with a fan 23 arranged centrally relative to the filter apparatus 24. The fan 23 again has a fan housing 21 with an axial air intake 52 on both sides and with a tangential air outlet 53 enclosed by an outlet connector 54. This outlet connector 54 again covers, in the same way, the wall aperture 35 in the front wall 13 to which the air conditioning box 19 of the air conditioning system with its air intakeport is connected. The filter apparatus 24 has two identically designed filter boxes 55, each with an air intake port 56 and an air outlet port 57, which are attached on the left and the right to the fan housing 51 and fixed to be able to rotate, the air intake ports 56 being oriented coaxially to the air intake 52 on both sides of the fan housing 51. A roof-like housing projection 58 (Figs. 13 and 15) is formed on each filter housing 55 in the region of the air intake port 56 and keeps water entering via the air passage port 17 in the bonnet 16 away from the air intake port 56. Each air intake port 56 is equipped with a fresh-air valve 58 which can be pivoted into two end pivot positions, completely masking the air intake port 56 in one of its end pivot positions and completely exposing it in its other end pivot position. In Fig. 13, both fresh-air valves 58 are shown in their open position. In Fig. 14, the fresh-air valve 58 of the right-hand filter box 55 is closed and that in the left-hand filter box 55 is opened. A plate-shaped dust filter 59 is arranged behind the air intake port 56 in each filter box 55 so that it covers the entire cross section of the air intake port 56. Upstream of the dust filter 59 in 12 the airflow direction a hollow cylindrical odour filter 60, which may for example be an active charcoal filter, is arranged in each filter box 55 so that the filter axis is coaxial with the axis of the air intake 52 of the fan housing 51 and the cylinder shell encloses the air intake 52. On the end face of the odour filter 60 facing the dust filter 59, or remote - from the air intake 52 of the fan housing 51, a bypass valve 61 is pivotably arranged. The bypass valve 61 is again pivotable between two end pivot positions, completely masking the clear cross section of the interior space of the hollow cylindrical odour filter 60 in one end pivot position (in the left-hand filter box 55 in Figs. 13 and 14) and completely exposing it in its other end pivot position (in the right-hand filter box 55 in Figs. 13 and 14).

As is apparent from the diagrammatic sectional illustration in Figs. 18 and 19, one quarter of the cylinder shell is cut away in each hollow cylindrical odour filter 60 and replaced by a housing wall 62 in the shape of one quarter of an arc of a circle, Formed on each filter box 55 is an air induction connector 63, which opens in the region of the cut- away portion of the odour filter 60. As Fig. 14 shows, each air induction connector 63 is placed on one of two air circulation ports 64 in the front wall 13 which are arranged at a distance from the wall aperture 35. Via these air circulation ports 64, circulating air can be aspirated from the passenger compartment 11 by the fan 23. The openings 66 of the two air induction connectors 63 are each equipped with an air circulation valve 65, the cut-away portions in the hollow cylindrical odour filters 60 making it possible for the air circulation valves 65 to pivot into the odour filters 60, which results in a shortening of the overall structural length of the module 20'. Each air circulation valve 65 is in turn pivotably arranged between two end pivot positions so that it completely exposes the opening 66 of the air induction connector 63 in one of its end pivot positions (Fig. 14, right-hand filter box 55, and Figs'. 18 and 19) and completely closes it in its other end pivot position (Fig. 14, left-hand filter box 55). Fig. 18 shows, in the same way as Fig. 14, that with the air circulation valve 65 opened the bypass valve 61 in the righthand filter box 55 is opened. The circulating air aspirated by the fan 23 flows via the air circulation port 64 in the front wall 13 directly into the air intake 52 of the fan housing 5 1, circumventing the odour filter 60. Fig. 19, by contrast, shows that the bypass valve 61 is closed. The circulating air aspirated via the opened air circulation valve 65 now flows radially from outside to inside through the cylinder shell of the odour filter 60 to the air intake 52 in the fan housing 5 1.

13 In Fig. 13 and Fig. 14, air flow arrows in the left-hand filter box 55 illustrate how, with the air circulation valve 65 closed and the freshair valve 58 opened, air from the plenum chamber 21 is aspirated via the dust filter 59, and, with the bypass valve 61 closed, flows radially through the cylinder shell of the hollow cylindrical odour filter 60 from outside to inside and then enters the air intake 52 of the fan housing 51. Corresponding flow arrows in the right-hand filter box 55 in Fig. 13 show how, with the fresh-air valve 58 opened, air aspirated via the dust filter 59 with the bypass valve 61 opened flows directly through the hollow cylindrical interior space of the odour filter 60 into the air intake 52 in the fan housing 5 1, circumventing the filter surface of the odour filter 60.

In all diagrammatic illustrations, the fan wheel in the fan 23 is designated 45 and the electric motor for driving the fan wheel 45 is designated 44.

Fig. 20 shows diagrammatically a modified ventilation module 20' in longitudinal section, in other words in the same view as in Fig. 13. It differs from the module 20' shown in Fig. 13 only in that the plateshaped dust filters 59 are not oriented transversely to the axis of the module and, in the installed position, thus do not stand approximately vertically or slightly inclined to the vertical, but are oriented parallel to the axis of the module and lie approximately horizontally in the installed position. The two dust filters 59 are here combined to form a single filter 59', the filter 59' extending above the two odour filters 60 and the fan housing 51 and parallel to the fan axis and the filter axes. The fresh air aspirated via the air intake ports 56 flows through the filter 59' from top to bottom and then, with the bypass valve 61 closed, through the shell of the hollow cylindrical odour filter 60 or, with the bypass valve 61 opened, circumventing the filter shell, directly via the interior space of the odour filter 60 into the air intake 52 in the fan housing 51. Otherwise, the structure and mode of function'of the ventilation module 20' according to Fig. 20 are identical with the module 20' illustrated in Fig. 13, so that identical components are provided with identical reference numbers.

14

Claims

Claim

1. A vehicle body having a front wall which partitions a passenger compartment from an engine compartment, closable by a bonnet, and together with a windscreen limits the passenger compartment at the front, having a plenum chamber which is sealed off from the engine compartment in front of the front wall and is limited at the top by a section of the bonnet having an air passage port and by a water collection channel beginning at the windscreen, and having a fan accommodated in the plenum chamber for the ventilation of the passenger compartment, which aspirates fresh air from the plenum chamber through a filter apparatus, wherein fan and filter apparatus are combined to form a ventilation module, a filter housing, receiving at least one air filter and having an air passage port arranged on the underside facing away from the bonnet and a removable filter lid covering the filter being attached to the axial air intake of a fan housing which is connected by an outlet connector, enclosing a tangential air outlet, to a wall aperture in the front wall.

2. A vehicle body according to Claim 1, wherein a plate-shaped dust filter covering the air intake port and an odour filter comprising a body of revolution are arranged within the filter housing one behind the other in the direction of air flow, so that the body of revolution lies coaxially to the air intake of the fan housing and its axis is aligned approximately at right angles to the normal of the plate-shaped dust filter.

3. A vehicle body according to Claim 2, wherein the body of revolution is a hollow cylinder, whose external surface is open to radial flow and encloses the air intake of the fan housing, and a bypass valve is arranged within the interior space of the hollow cylinder at its end face remote from the air intake so as to be able to pivot between two end pivot positions so that it masks the clear cross section of the interior space of the hollow cylinder in one of its end pivot positions and exposes it to the maximum in its other end pivot position.

4. A vehicle body according to Claim 2, wherein the body of revolution is a paraboloid with an external surface open to flow and enclosing with its circular aperture the air intake of the fan housing.

5. A vehicle body according to Claim 1, wherein a plate-shaped dust or combination filter, covering the air intake port, is arranged in the filter housing and the filter housing and filter lid form a circular swirl duct between the filter end and the air intake of the fan housing.

6. A vehicle body according to any one of Claims 2 to 5, wherein the filter housing has an air induction connector placed over an aperture in the front wall and opening in the interior of the filter housing behind the filter covering the air intake port, in the airflow direction, and a hemispherical air circulation valve which is associated with the air induction connector is arranged in the filter housing to be pivotable between two end pivot positions so that the opening of the air induction connector is masked in one of its end pivot positions and exposed in its other end pivot position.

7. A vehicle body according to Claim 6, wherein the arrangement of the hemispherical air circulation valve is such that it completely blocks the flow path from the plate-shaped filter to the fan in its end pivot position exposing the opening of the air induction connector and completely exposes it in its end pivot position masking the opening.

8. A vehicle body according to Claim 6 or 7, wherein a circulating air filter or filter screen is arranged in the filter housing at the opening of the air induction connector.

9. A vehicle body having a front wall which partitions a passenger compartment from an engine compartment, closable by a'bonnet, and together with a windscreen limits the passenger compartment at the front, having a plenum chamber which is sealed off from the engine compartment in front of the front wall and is limited at the top by a section of the bonnet having an air passage port and by a water collection channel beginning at the windscreen, and having a fan accommodated in the plenum chamber for the ventilation of the passenger compartment, which aspirates fresh air from the plenum chamber through a filter apparatus, wherein the fan and the filter apparatus are combined to form a ventilation module, two filter boxes, each receiving at least one filter and each provided with an air intake port and an air outlet port on both end faces of a fan 16 housing having an axial air intake and tangential air outlet enclosed by an outlet connector being attached on the fan housing and rotatable thereon so that their air outlet ports are coaxial with the air intake of the fan housing and the fan housing is attached by its outlet connector to a wall aperture in the frobt wall.

10. A vehicle body according to Claim 9, wherein a plate-shaped dust filter and a hollow cylindrical odour filter are arranged one behind the other, viewed in the airflow direction, in each filter box and, on the end face of the odour filter facing the dust filter, a bypass valve is arranged to be pivotable between two end pivot positions so that it completely masks the clear interior cross section of the hollow cylindrical odour filter in one of its end pivot positions and exposes it to the maximum in its other end pivot position.

11. A vehicle body according to Claim 10, wherein, within each hollow cylindrical odour filter, a quarter of the cylinder shell is cut away and replaced by a housing wall in the shape of a quarter of an arc of a circle, an air induction connector formed on each filter box and connected to an air circulation port in the front wall opens in the region of the cut-away portion, and an air circulation valve is arranged at the opening of the air induction connector to be pivotable between two end pivot positions so that the clear cross section of the opening is completely masked in one of its end pivot positions and exposed to the maximum in its other end pivot position.

12. A vehicle body according to Claim 10 or 11, wherein the plate-shaped dust filters in each filter box are arranged so that their filter surfaces extend transversely to the housing axis of the fan housing.

13. A vehicle body according to Claim 10 or 11, wherein the plate-shaped dust filters in each filter box are arranged so that their filter surfaces extend transversely to the housing axis of the fan housing, and the two dust filters are combined to form a one-piece filter which extends beyond the fan housing and the two odour filters.

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14. A vehicle body according to any one of Claims 9 to 13, wherein each filter box has a roof-like housing projection at its air intake port to retain water flowing into the plenum chamber.

15. A vehicle body according to any one of Claims 9 to 14, wherein a fresh air valve, pivotable between two end pivot positions, is arranged at the air intake port of each filter box so that it completely masks the air intake port in one of its end pivot positions and completely exposes it in its other end pivot position.

16. A vehicle body substantially as described herein with reference to, and as illustrated in, the accompanying drawings.