Abstract:
Device for air intake of a heat engine including: —a main circulation system ( 105 ) which connects a supercharging apparatus ( 106 ) or an air intake manifold ( 107 ) which incorporates a heat exchanger ( 108 ), —a bypass system ( 109 ) linked to the main circulation system along the exchanger, the bypass system incorporating a heating apparatus ( 29 ), —a circuit selection device mounted between the main circulation system and the bypass system to channel at least some of the air into one or the other system.

Description:
[0001]    The present invention relates to an air intake device for a heat engine. 
       BACKGROUND OF THE INVENTION 
       [0002]    In supercharged engines, an intake device such as this comprises a main circuit incorporating an intercooler and connecting a supercharger such as a compressor of a turbocompressor to the intake duct of the heat engine. The supercharger further comprises a non-cooled bypass circuit connected to the main circuit on each side of the intercooler. Valves are fitted on the main circuit and the bypass circuit and are controlled by the engine electronic control unit (ECU) in order to direct air toward one or other circuit so as to obtain, in the intake duct, an air temperature that is suited to the desired engine performance. 
         [0003]    This system is not, however, always capable of obtaining optimal engine operation, particularly at start-up and at low idle. 
       OBJECT OF THE INVENTION 
       [0004]    One object of the invention is to provide a means for improving engine operation. 
       SUMMARY OF THE INVENTION 
       [0005]    To this end, the invention provides an air intake device for a heat engine, comprising:
       a main circuit which connects a supercharger to an intake manifold and which incorporates a heat exchanger,   a bypass circuit connected to the main circuit on each side of the heat exchanger, the bypass circuit incorporating a heating member,   a circuit selection member mounted between the main circuit and the bypass circuit in order to direct at least some of the air to one or other circuit.       
 
         [0009]    The heating member can be used to increase the air temperature, thus making it easier to start the engine and stabilizing engine operation at low idle. The temperature ranges that can be obtained in the intake duct are broadened. 
         [0010]    Advantageously, the selection member comprises a valve comprising a body delimiting at least a first pipe connected to the bypass circuit and a second pipe connected to the main circuit, the heating member being incorporated into the first pipe. 
         [0011]    The heating member is incorporated into the valve, thus limiting the bulk of the intake device. 
         [0012]    As a preference, the valve body is associated with a heat sink member and, possibly, the heat sink member is designed to connect the valve body to an upper part of a cylinder of the heat engine. 
         [0013]    This then limits the degree to which the valve body is heated, possibly using the cylinder head as a heat sink. 
         [0014]    Other features and advantages of the invention will become apparent from reading the following description of one particular nonlimiting embodiment of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0015]    Reference will be made to the attached drawings, among which: 
           [0016]      FIG. 1  is an elevation of a valve according to the invention, 
           [0017]      FIG. 2  is a section on II-II of  FIG. 1 , 
           [0018]      FIG. 3  is a section on III-III of  FIG. 1 , with the first shutter in its open position and the second shutter in its closed position, 
           [0019]      FIG. 4  is a section on IV-IV of  FIG. 3 , 
           [0020]      FIG. 5  is a perspective part view with the first shutter in an intermediate position between its first closed position and its open position and the second shutter in its closed position, 
           [0021]      FIGS. 6 and 7  are views similar to that of  FIG. 5 , with the first shutter in its second closed position and the second shutter in its closed position and in its open position, respectively, 
           [0022]      FIG. 8  is a schematic view of an engine equipped with an intake device according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0023]      FIG. 8  depicts an internal combustion piston-type heat engine comprising a block  100  delimiting cylinders  101  which are connected to an intake device denoted overall as a  102  and to an exhaust device  103  known per se. The heat engine is supercharged. The engine components other than the intake device are known per se and are not described here. 
         [0024]    The intake device  104  comprises a main air-supply circuit  105  connecting the compressor  106  to the intake duct (or manifold)  107  and incorporating a heat exchanger, in this instance an intercooler  108  known per se. An air-supply bypass circuit  109  is connected to the main circuit  105  on each side of the intercooler  108 . The bypass air circuit  109  is connected to the main circuit  105  directly downstream of the intercooler and is connected by a valve  99  upstream of the intercooler. 
         [0025]    With reference to  FIGS. 1 to 7 , the valve  99  used in this embodiment of the invention comprises a body denoted overall as 1 delimiting a first pipe  3  and a second pipe  4  opening into a third pipe  2 . The first pipe  3  is connected to the bypass circuit  109 . The second pipe  4  and the third pipe  5  are connected to the main circuit  105 , the second pipe  4  being connected to the intercooler and the third pipe  5  to the compressor. The body  1  and the pipes  3  and  4  are depicted only partially in  FIGS. 5 to 7 .  FIG. 8  shows that the body  1  is connected to the upper part of the cylinders  101  by a heat sink member  111  formed of a component made of a thermally conductive material. 
         [0026]    The first pipe  3  is equipped with a first double shutter or butterfly  5  secured to a spindle  6  mounted to pivot on the body  1 . The spindle  6  has one end projecting beyond the body  1  and rotating as one with a toothed first transmission wheel  7  in mesh with an intermediate gearing  8  itself in mesh with a pinion  9  secured to an output shaft of a motor  10  mounted on the body  1 . The motor  10  is a DC motor known per se connected to a source of electrical power and to a control module both of which are also known per se and are not depicted in the figures. A torsion spring  11  extends helically around said end of the spindle  6  with one end connected to the transmission wheel  7  and one end connected to the body  1 . The spring  11  returns the butterfly  5  to the open position (depicted in  FIGS. 2 to 4 ). The transmission wheel  7  is provided with studs  12 ,  13  which are designed to collaborate with a stop  14  secured to the body  1 . When the stud  12  is in abutment against the stop  14 , the butterfly  5  is in a first closed position (depicted in  FIG. 6 ) and when the stud  13  is resting against the stop  14 , the butterfly  5  is in a second closed position (depicted in  FIG. 7 ). The butterfly  5  is substantially perpendicular to the pipe  3  when in its first closed position and in its second closed position, these positions being approximately 180° apart. Resistors, depicted schematically as  29 , extend into the pipe  3  downstream of the butterfly  5  and are fixed to the body  1 . The resistors  29  allow the fluid to pass and are in the form of fins made of aluminum or of fine resistive strips the thickness and shapes of which are designed not to impede or disturb the flow of the fluid. The resistors  29  comprise means, known per se and not depicted, of connection to an electrical power supply. The resistors  29  form a device for heating the air in the bypass circuit  109 . 
         [0027]    The second pipe  4  is equipped with a second double shutter or butterfly  15  secured to a spindle  16  which is mounted to pivot on the body  1  and which has one end projecting beyond the body  1  on which a second transmission wheel  17  is mounted such that it can pivot. A support is fixed to this end of the spindle  16 . The support defines two arms  18 ,  19  extending radially from the projecting end of the spindle  6 , away from one another. Each arm  18 ,  19  is provided with a finger  20 ,  21  housed in a circular-arc-shaped groove  22 ,  23  formed in the transmission wheel  17 . The arm  19  has a free end intended to butt against a stop  24  secured to the body  1  and defining the closed position of the butterfly  15  (which position is depicted in  FIGS. 2 to 6 ). A torsion spring  25  extends in a helix around said end of the spindle  16  and has one end connected to the finger  21  and an opposite end connected to the body  1  in order to return the butterfly  15  to the closed position. In the open position, the butterfly  15  runs substantially along the axis of the pipe  4 . 
         [0028]    The stops  14 ,  24  are fixed to a support the position of which can be adjusted relative to the body  1 . 
         [0029]    The valve thus created has:
       a normal or primary mode of operation in which the butterfly  15  is in the closed position and the butterfly  5  is adjustable in terms of position between its open position and its first closed position (intermediate position depicted in  FIG. 5 ),   an “off” mode in which the butterfly  15  is in its closed position and the butterfly  5  is in its first closed position ( FIG. 6 ),   a secondary mode of operation in which the butterfly  15  is in its open position and the butterfly  5  is in its second closed position ( FIG. 7 ).       
 
         [0033]    In the normal mode of operation, the motor  10  can bring the butterfly  5  into any position between its open position and its first closed position (refer to the intermediate position depicted in  FIG. 5 ). When the butterfly  5  is in the open position ( FIG. 3 ), the fingers  20 ,  21  are housed in one end  22 . 1 ,  23 . 1  of the grooves  22 ,  23 . When the transmission wheel  7  pivots between the position in which the butterfly  5  is open and the first closed position thereof, the transmission wheel  7  drives the transmission wheel  17  (direction of rotation  40  in  FIG. 3 ), causing the fingers to slide along the grooves  22 ,  23  toward the other end  22 . 2 ,  23 . 2  of these grooves. The butterfly  15  is therefore immobile, held in its closed position by the spring pressing the protrusion of the arm  18  against the stop  24 . 
         [0034]    When the butterfly  5  is in its first closed position, the fingers  20 ,  21  are housed in the ends  22 . 2 ,  23 . 2  of the grooves  22 ,  23  and the butterfly  15  is in its closed position so that the valve is in its “off” mode ( FIG. 6 ). 
         [0035]    When the butterfly  5  is returned to its open position from its first closed position, the transmission wheel  7  drives the transmission wheel  17  and the fingers move from the end  22 . 2 ,  22 . 3  of the grooves  22 ,  23  to the ends  22 . 1 ,  23 . 1  without causing the butterfly  15  to move. 
         [0036]    When the transmission wheel  7  is moved in order to bring the butterfly  5  into its second closed position, the transmission wheel  7  causes the transmission wheel  17  to rotate in the direction referenced  30  in  FIG. 3 . Because the fingers  19 ,  20  are in abutment against the ends  22 . 1 ,  23 . 1  of the grooves  22 ,  23 , the pivoting of the transmission wheel  17  will cause the support and therefore the spindle  16  and the butterfly  15  to pivot. When the butterfly  5  reaches its second closed position, the butterfly  15  is in its open position. The valve is in its secondary mode of operation ( FIG. 7 ). 
         [0037]    When the butterfly  5  is returned from its second closed position to its open position (under the action also of the spring  11 ), the transmission wheel  17  is driven in the opposite direction (the direction referenced  40 ) by the transmission wheel  7  and the spring  25  exerts on the finger  21  a return force returning the butterfly  15  to its shutting-off position. 
         [0038]    The fingers  20 ,  21  and the grooves  22 ,  23  thus form a one-way drive member driving the butterfly  15  in one direction (the direction  30 ), this member being positive (or active) when the butterfly  5  is being driven from its open position to its second closed position. 
         [0039]    It will be noted that the spindles  6 ,  16  of the butterflies  5 ,  15  are sited near the third pipe  2  and that:
       in the open position, the butterflies  5 ,  15  have a part projecting into the pipe  2 , preferably as far as the axis of the pipe  2 , in order to guide the gases and act as deflectors;   in the closed position, the butterflies  5 ,  15  lie near the wall of the pipe  2 , and preferably approximately flush with the pipe  2  and parallel to the wall thereof, in order to limit the creation of regions in which the gases can recirculate or cause other disruptions to the flow, so as to reduce pressure drops.       
 
         [0042]    Of course, the invention is not restricted to the embodiment described and alternative forms of embodiment may be added thereto without departing from the scope of the invention as defined by the claims. 
         [0043]    In particular, the valve may have a structure other than that described, particularly as far as the layout of the pipes, the geometry of the butterflies, the way in which the second transmission wheel is driven, the means actuating the butterflies, etc., are concerned. The transmission wheels may be belt-driven. The motor may be mesh with the first transmission wheel and with the second transmission wheel, the first transmission wheel then no longer serving as the link between the motor and the second transmission wheel. The body may be made in one or more parts. In place of a double shutter of the butterfly type, it is possible to use single shutters. 
         [0044]    The member returning the second butterfly may be a mechanical or electrical drive member. 
         [0045]    The one-way drive member may have some structure other than that described and, for example, have just one finger and one groove. A finger may also be secured to the transmission wheel  17  in order to rest against the arm  19 . 
         [0046]    It goes without saying that the design whereby at least one of the butterflies  5 ,  15  in the open position has a part projecting into the third pipe  2  and at least one of the butterflies  5 ,  15  in the closed position lies substantially close to, or even flush with, the third pipe  2  can be applied to any type of valve with three pipes, for example one inlet and two outlets, with two butterflies operated by one or two motors. 
         [0047]    Likewise, the resistors  29  can be used in any type of valve that has three pipes, particularly one inlet and two outlets. The heating member may be provided in one and/or other of the pipes and have a different structure from that described. The heating member may also be positioned at a different location in the bypass circuit  109 . 
         [0048]    Furthermore, the return direction of the springs and the return position of the butterflies may differ from those described hereinabove. 
         [0049]    As an alternative, it would have been possible to conceive of the butterflies being actuated by means of two coupled motors each associated with one of the butterflies.