FR2706818A1 - - Google Patents

Abstract

A transmission device (33) rotates cam pushers (59, 60) around an axis (Z) when a cable (3), operated from the dashboard of a vehicle, moves longitudinally. The fingers (59, 60) sequentially control two recirculation air intake flaps (22), via cams (59, 60). The cable is connected to a flexible rack (41) constrained by guides (49, 53, 54, 55) to engage with a toothed wheel (42). Application to ventilation-heating-air conditioning units for the automobile.

Description

The present invention relates to a transmission device, as well as to a

  ventilation-heating and / or air-conditioning unit, in particular for motor vehicles, which is provided with such a device for the transmission of an actuating force to one or more

  driven organs integrated into the unit.

  In current motor vehicles, a ventilation, heating and / or air conditioning unit is most often installed under the front hood of the vehicle, on the back of the dashboard, where the smallness of the available space requires the unit reduced external dimensions. As a general rule, the unit is in the form of a box often comprising two air inlets communicating one with the outside atmosphere, and

  the other with the passenger compartment, each associated with a shutter.

  The housing contains various functional organs, in particular a fan, the suction of which communicates with one or the other of the air inlets and the discharge of which opens into the passenger compartment of the vehicle, as well as a heating radiator and, in the case if necessary an air conditioning evaporator, both placed in the air path. A mechanical transmission device is further provided for transmitting to the shutters an actuating force produced by the operation of a manual control button located on the dashboard of the vehicle. The transmission device drives two cams which ensure the coordinated control of the movements of the two flaps, to close the two flaps and thus eliminate any ventilation or on the contrary close only one and adjust the opening of the other, to provide ventilation from outside air or on the contrary

closed circuit.

  A transmission device known in this application comprises a cable capable of being moved in translation from the control button of the unit, and a pivoting lever on which the active end of the cable is articulated. This lever cooperates with the cams, which

  are each attached to one of the flaps.

  The known transmission device therefore transforms the translation of the cable, in one direction or the other, into a rotation of the lever, which therefore acts in

pull or push.

  This known transmission device has the advantage

  to be extremely simple and economical.

  However, its dynamic performance can only be mediocre. Indeed, on either side of a position for which the longitudinal axis of the cable is tangential to the circular path of the active end of the cable, the lever has only a relatively reduced range of rotation beyond which the orientation of the cable becomes very unfavorable for transmitting a torque to the lever. It follows that the effective stroke of the lever is itself greatly limited. Consequently, to be able to generate a displacement of sufficient amplitude of the flaps, the cams have to undergo a greater force and / or applied less favorably, which increases the force to be transmitted, friction and wear, hence certain risks of blocking, or even breaking. We could extend the lever, but that would increase the bulk. In addition, in the known transmission device, the cable, flexible and poorly guided, is liable in the pushing phase to completely exit its rectilinear path of action instead of driving the lever. Ultimately, it should be

  provision of ventilation unit manufacturers-

  heating and / or air conditioning for motor vehicles, a new transmission device offering good

  dynamic performance and high reliability.

  This is precisely the aim which the present invention has set for itself, which for this purpose relates to a transmission device characterized in that it comprises, on the input side, a first transmission element consisting of a flexible rack and, output side, a second transmission element consisting of a toothed part, movable in rotation, comprising a toothing of circular envelope centered on the axis of rotation of the toothed part, toothing with which the flexible rack meshes, the transmission device being further provided with a flexible rack guide structure over a predetermined angular sector

  meshing with the rotating toothed part.

  The transmission device according to the invention has an excellent dynamic performance; in fact, the rack, when it is moved in translation from the entry of the device, exerts by meshing, on the toothed part, movable in rotation, a torque of constant intensity available over an increased range of rotation, with the consequence a widely useful run

  amplified at the output of the transmission device.

  The rack can have a flexibility compatible with a relatively small diameter of teeth. The transmission device according to the invention

  can thus have a small overall size.

  Despite this flexibility, the rack is able to work in compression without deforming because the invention eliminates excessive forces due to the drawbacks of the cable system. In addition, as the rack attacks the toothed part always in the same place and without undergoing lateral movements, it can be guided over almost its entire path. The reliability of the device and its approval for use

are increased.

  In the application to a heating unit-

  ventilation and / or air conditioning, the flexible rack will then be secured to a unit control member, such as an mQ cable by a rotary button. The toothed part, movable in rotation, will be connected, directly or by means of cams to at least one constituent member driven by the unit, such as a flap. The transmission device according to the invention also has the advantage of being able to be constructed from structurally simple elements and

  relatively inexpensive, easy to assemble.

  Thus, for example, the toothed part, mobile in rotation, of the transmission device can, in a preferred embodiment of the invention, consist of a toothed wheel of the kind used with the

toothed belts.

  Furthermore, the guide structure of the flexible rack may advantageously be constituted by a fixed guide having, opposite the teeth of the moving part in rotation, a smooth arcuate surface, concentric with the latter, against which the rack will apply. , according to a sliding contact at

  gentle friction, by its face opposite its own toothing.

  The flexible rack can be made of a plastic material readily available on the market, preferably a plastic material having a self-lubricating power promoting the sliding of the

  rack along the fixed guide.

  Thanks to the relatively wide useful travel provided by the invention, it is even possible to envisage extending the field of action of the transmission device and the cam mechanism to the control of other members.

led integrated into the unit.

  A ventilation-heating and / or air conditioning unit, provided with a transmission device according to the invention, will now be described in more detail, but only purely by way of non-limiting illustration, with reference to the appended drawings in which : - Figure 1 is a partial schematic view, in longitudinal section, of the front of a motor vehicle equipped with such a unit; - Figure 2 is a plan view, with sections and cutaway, of the interior of the housing of the ventilation-heating and / or air conditioning unit according to the invention, showing most of the components; - Figure 3 is a plan view on a larger scale illustrating more particularly the transmission device according to the invention; - Figure 4 is a sectional view along line IV-IV of Figure 3; and - Figures 5, 6 and 7 are schematic views illustrating the ventilation-heating and / or air conditioning unit placed in three operating modes under the control of the device

Figure 3 transmission.

  Figure 1 illustrates the conventional mounting of a ventilation-heating-air conditioning unit 1 according to the invention, under the front cover A of a motor vehicle and against an apron B supporting on the other side the dashboard C of the latter . A rotary button 2 accessible on the dashboard C, allows the occupants of the vehicle to manually actuate, in traction or in pushing, a cable 3 for controlling the ventilation-heating and air conditioning unit 1, housed in free sliding in a sheath 4; an air distribution duct 5, which, like the sheath 4, passes through the apron B, also opens the outlet

  of unit 1 in the passenger compartment D of the vehicle.

  This unit 1, shown on a larger scale in FIG. 2, is constructed from a housing 6 formed by a rear housing element 7 and a front housing element 8, fixed to one another . The terms "front" and "rear" used in this

  description to define the relative position of the parts

  constituting the housing 6 and its elements 7 and 8, refer to the direction of travel towards the front of the vehicle. In addition, the terms "lower" and "upper" are used with reference to the heading

to use the unit 1.

  As FIGS. 2 and 4 show jointly, the rear casing element 7 is essentially defined by two side walls 9 and 10, an upper wall 11 largely constituted by a cover 20, and a lower wall 12; it further comprises an internal partition 13, separating a lower compartment 14 of great height for the circulation of air and, on the other hand an upper compartment 15 of low height (see FIG. 4) for receiving the control mechanism. As can be seen in FIG. 2, the lower compartment 14 of the rear housing element 7 has a first orifice 16 formed through one of the side walls 9 of the rear housing element, and comprises the rear a second orifice 17 bordered by a flange 19 by which the housing 6 is fixed to the bulkhead B opposite a cutout E thereof, connected to a duct, not shown, which, passing under the dashboard C of the vehicle, opens in the passenger compartment D of the latter. The two orifices 16 and 17 have a rectangular shape and cover the entire height of the lower compartment 14 of the element of

rear housing 7.

  Returning to FIG. 2, it can be observed that a shutter for closing and adjusting the flow rate 21, respectively 22, is mounted in the vicinity of each of the orifices 16, 17 of the lower compartment 14 of the rear casing element 7. For their mounting, the two flaps 21, 22 are each provided with two pins 23, 24 or 25, 26 received in free rotation respectively in the internal partition 13 and the bottom wall 12 of the rear housing element 7, as shown Figure 4 in which the flap 21, normally located in front of the cutting plane, is shown in phantom in its open position. The pivot axes X, Y of the two flaps 21, 22 are substantially perpendicular to the internal partition 13 and to the bottom wall 12 of

the rear housing member 7.

  As will be described more

  detailed in the following description, the command

  selective coordinated opening and closing movements of the two valves 21, 22 is done using two cams 31, 32 adapted to be actuated by a transmission device 33 receiving on its input an actuating force generated from rotary knob 2

  of the dashboard C of the vehicle.

  A circular opening 34 communicates the lower compartment 14 of the rear housing element 7 with the interior of the front housing element 8. The latter constitutes the outer casing of a radial fan 35 coupled to an electric motor 36 supported by a support flange 37 fixed in a wide opening 38

  of the front wall 39 of the front housing element 8.

  The opening 34 defines the axial suction of the fan 35 whose tangential discharge, not visible in the figures, is connected to the air distribution duct 5

(figure 1).

  The rear housing element 7 for its part contains means for heating, cooling and dehumidifying the air, not shown, which, being of a design and operating mode known to those skilled in the art will not be described in more detail. The transmission device 33 (Figures 3 and 4), housed inside the upper compartment 15 of the rear housing element 7, consists of a flexible plastic rack 41 meshing with

  a toothed part of the periphery of a toothed wheel 42.

  The flexible rack 41 comprises a body 43 produced in the form of a long strip of rectangular section and a series of parallel teeth 44, extending on one of the large faces of the body 43, perpendicular to its longitudinal axis. The thickness of the body 43 is substantially equal to the height of the teeth

rack 41.

  The toothed wheel 42 carries on its circumference a straight toothing 45 complementary to the toothing of the flexible rack 41, defined by the teeth 44. It is also mounted for free rotation on the inside of the cover 20 of the rear housing element. 7, in a position such that its axis of rotation Z is parallel to the axes of pivot X, Y of the flaps 21, 22

and equidistant from these axes.

  As shown in FIG. 4, the toothed wheel 42 comprises a central bearing 46 in which engages with a minimum set of rotation a cylindrical axis 47

  protruding from the inside of the cover 20.

  Returning to FIG. 3, it can be seen that an end portion 41a of the flexible rack 41 is fixed, by means of a rivet 48, to the active end of the

  ventilation-heating unit control cable 3

  air conditioning, actuated by the rotary control button 2 (figure 1). This end portion 41a of the flexible rack 41 is also inserted with free sliding in a guide sleeve 49 fixed under the dashboard C of the vehicle. The sheath 4 of the cable 3 abuts against a first end of the guide sleeve 49 whose second end 50 penetrates slightly through a cutout K in the deck B. From there, the flexible rack 41 is introduced into the upper compartment 15 of the rear housing element 7 passing through an opening 51 formed in the rear wall 52 of the latter. A short distance from the guide sleeve 49 and in the same rectilinear axis W tangent to the circular envelope of the toothing 45 of the toothed wheel 42, the flexible rack 41 is received with free sliding between two parallel guide plates 53, 54, which at the rear have respective diverging extensions 53a, 54a. The inner guide plate 53, adjoining the teeth 44 of the rack, is interrupted slightly below the envelope of the toothing 45 of the latter, while the outer guide plate 54 extends first of all to at the point of tangency of the envelope of the toothing 45 of the toothed wheel with the axis W, then is extended by a wall element 55 bent over

  around 90 around the toothed wheel 42.

  This wall element 55 has, facing the teeth 45 of the toothed wheel 42, a smooth, curved guide surface 56, concentric with the envelope of the teeth 45 of the toothed wheel 42. The radial distance between the envelope of the toothing and the surface 56 substantially corresponds to the thickness of the body 43 of the flexible rack 41. Thus, the curved wall element constitutes, for the flexible rack 41 engaged in free sliding in the guide sleeve 49 and between the plates guide 53, 54, a fixed guide forcing the rack 41 to mesh with the toothed wheel 42. The two guide plates 53, 54 with their extension 53a, 54a and the guide 55 are integral with the

cover 20.

  As can be seen in Figures 3 and 4, the upper pivot 23 or 25 of each of the flaps 21, 22 passes completely through the internal partition 13 of the rear housing element 7 and is secured slightly beyond this last at the terminal part 63 or 64 of a respective cam 31 or 32. The cams 31, 32 have the form of thick plates engaging, by their front parts, in the space formed between the toothed wheel 42 and

  the internal partition 13 of the rear boot element 7.

  Each cam 31 or 32 has on its upper face an imprint 57 or 58, the contoured contour of which forms a cam path called to cooperate with a pusher finger

  cylindrical cam 59 or 60 carried by the toothed wheel 42.

  In FIG. 5, in which the flexible rack 41 and the toothed wheel 42 of the transmission device 33 have been drawn in phantom, the two cams 31, 32 can be seen in full, respectively linked to the flaps 21, 22. These are shown in their closed position, which corresponds to an intermediate angular position of the toothed wheel 42. It can be seen by comparison of FIGS. 5 and 6 that by rotating the toothed wheel 42 in the direction P, obtained by exerting a longitudinal thrust on the rack 41, the flap 21 opens, while the flap 22 remains closed (FIG. 6). This is due to the fact that from the situation shown in FIG. 5, the pusher 60 associated with the cam 32 will circulate longitudinally in the cavity of the cam 32, extending approximately tangentially along the path that will follow the pusher 60. On the contrary, the pusher 59 immediately abuts against a face 68 of the imprint of the cam 31 which is associated with it because this face 38 extends transversely to the path that the pusher 59 will have to follow. This done pivot the cam 31 and with it the flap 21 associated therewith. To return to the position of FIG. 5, it suffices to actuate the rack in traction. The pusher 60 travels in the opposite direction along the associated footprint, while the pusher 59 returns the flap 21 to the closed position because it abuts against a face 67 of the footprint of the associated cam 31, the face 67 being substantially opposed to the

face 68.

  If we go beyond the position of FIG. 5, by pulling the rack up to the position of FIG. 7, it is this time the pusher 59 which circulates freely in the cavity of the cam 31 without rotating it, while the pusher 60 rotates the flap 22 to the open position by abutting against a face 73 of the imprint of the cam 32. On returning to the position of Figure 5, the flap 22 closes because the pusher 60 abuts against a face 74 of the imprint of the cam 32, the

  face 74 being opposite to face 73.

  We will now describe more particularly with reference to FIGS. 5, 6 and 7, in which way the control of the operating mode of the ventilation-heating and / or air conditioning unit 1 is carried out.

  by the transmission device 33 and the cams 31, 32.

  The rotary knob 2 of the unit 1 is adjustable on either side of a neutral position controlling the setting

  at rest (figure 5) of the ventilation-heating unit-

air conditioning 1.

  The connection between the rotary knob 2 and the cable 3 is designed so that the total adjustment stroke of the knob 2 and the resulting sliding stroke for the cable 3 and the rack 41 correspond to the angular stroke of approximately 90 necessary for that the toothed wheel 42 passes from the extreme position of FIG. 6 to that of FIG. 7. The flexible rack 41, maintained on a rectilinear trajectory by the guide sleeve 49 and the two guide plates 53, 54, faithfully transmits its movement with the toothed wheel 42, under the forced line of the guide 55, and, sliding with the minimum of friction as necessary to the free end 56a of the guide surface 56 of the guide 55, even when

  the rack works in thrust.

  When the shutter 21 is open, an atmospheric air inlet, possibly reinforced by the fan 35, is made through the orifice 16 to

  ensure normal operation of unit 1.

  The flap 21 has a bent shape, in the manner of a guide vane, which also promotes the path of the incoming air stream to the opening

suction 34 of fan 35.

  When the flap 22 is open, the flap 21 is closed and the suction opening 34 of the fan 35 is only connected to the interior space of the passenger compartment D of the vehicle. The passenger compartment D of the vehicle is then the subject of closed circuit ventilation, that is to say a circulation of the air it contains, without absorption of atmospheric air. This operating mode is useful for example in the event of air pollution at

outside of the vehicle.

  It is possible to extend beyond 90, or even 180, the range of rotation of the toothed wheel 42 which can allow, using additional cams, to actuate from a single transmission device in accordance with the invention, one or more other control members inside the control unit

  ventilation-heating-air conditioning 1.

  The transmission device according to the invention, although having been described in its use at

  the interior of a ventilation-heating unit-

  air conditioning, may find other applications.

Claims (10)

  1. Transmission device (33) intended, in particular in a ventilation-heating and / or air conditioning unit (1), to communicate an actuating force to one or more driven members (21, 22), this device comprising, on the input side, a first transmission element (41) capable of being moved in translation and, on the output side, a second transmission element (42) movable in rotation, mechanically controlled by the first transmission element, characterized in that the second transmission element transmission is a toothed part (42) comprising a toothing (45) of circular envelope centered on the axis of rotation (Z) of the toothed part, and the first transmission element consists of a flexible rack (41) meshing with the toothing (45) of the toothed part (42), the transmission device being further provided with a structure (55) for guiding the flexible rack (41) over a predetermined angular sector of engagement with the toothed part (42).   2. Transmission device according to claim 1, characterized in that the guide structure comprises a fixed guide (55) disposed in the vicinity of the toothed part (42) and having, facing its teeth (45), a smooth surface arched (56), concentric with the latter, surface with which the back of the   flexible rack (41) is in sliding contact.   3. Transmission device according to claim 2, characterized in that the flexible rack (41) is made of a self-lubricating plastic. 4. Device according to any one of   Claims 1 to 3, characterized in that the part   gear is a gear for rack (42).   5. Transmission device according to one   any of claims 1 to 4, characterized in   that it comprises means for guiding a part of the rack (41) which is out of engagement with the toothed wheel (42), along a path (W) substantially rectilinear tangent to the circular envelope of the teeth of the toothed wheel ( 42). 6. Transmission device according to one of   claims 1 to 4, characterized in that the part   end (41a) of the rack (41), distant from the toothed part (41), is inserted with free sliding in   a longitudinal guide sleeve (49).   7. Transmission device according to one   any of claims 1 to 6, characterized in that   that in the immediate vicinity of its point of tangency with the toothing (43) of the toothed part (42), the flexible rack (41) is engaged in free sliding between two   longitudinal guide plates (53, 54).   8. ventilation-heating and / or air conditioning unit (1) for an enclosure, in particular for the passenger compartment (D) of a motor vehicle, unit which comprises a housing (6) provided with at least one inlet air (16, 17) as well as several functional members, including a fan (35), mounted inside the housing, between the air inlet (16) and an air outlet (5) intended to connect the discharge of the fan to the enclosure, said unit further comprising a member for controlling its operation (2, 3), capable of exerting a traction and pushing force, and a transmission device (33) whose input is connected to the control member (2, 3) and the outlet coupled to one or more driven members, which include an opening and closing flap (21, 22) of the air inlet of the housing, the device transmission consisting of a first transmission element (41) movable in translation, integral with the control member of the unit, and a second transmission element (42) movable in rotation, mechanically controlled by the first transmission element, said unit being further characterized in that the second transmission element of the transmission device is a toothed part (42) having a toothing (45) circular envelope centered on the axis of rotation (Z) of the toothed part, and the first transmission element consists of a flexible rack (41) meshing with the teeth (45) of the toothed part (42), the device being further provided with a structure (55) forcing the flexible rack (41) into a predetermined angular sector of engagement with the toothed part (42).   9. ventilation-heating and / or air conditioning unit according to claim 8, characterized in that the toothed wheel (42) is connected to cam means (31, 32, 59, 60) designed to actuate   sequentially at least two driven organs (21, 22).   10. Ventilation-heating and / or air conditioning unit according to claim 8, the housing of which comprises two air inlets (16, 17) intended to be placed in communication, for one, with the atmosphere and, for the other, with the interior space of said enclosure, as well as two pivoting flaps (21, 22) each movable, opposite a respective air inlet, between an open position and a position of closing of the latter, said unit further comprising means for coordinated control of the movement of the flaps, characterized in that these control means comprise two cams (31, 32), each subject to a respective flap and cooperating with a respective pusher finger (59, 60) carried by the toothed part (42), the profile of the cam tracks of the cams (31, 32) and the relative position of the pusher fingers (59, 60) being such that in a determined angular position of the part toothed (42), the two cams are in a first orientation ion placing the flaps (21, 22) in their closed position and that, during a rotation in one direction (P) from this angular position, only a first cam (31) is moved to bring the associated flap ( 21) in its open position and, when rotating in the other direction (R), only the second cam (32) is ready to bring the associated flap (22) into its open position.