Abstract:
The present invention provides an apparatus for deactivating one or more cylinders of an internal combustion engine. The apparatus comprises: a surge tank being provided with a plurality of chambers, said chambers temporarily storing air being provided from a throttle body; an air distributor for selectively providing air to said chambers of said surge tank; and an intake manifold connected to the chambers of the surge tank.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to an internal combustion engine, and more particularly, to an apparatus for selectively deactivating one or more cylinders of an internal combustion engine.  
         BACKGROUND OF THE INVENTION  
         [0002]    Generally, in an internal combustion engine, fuel is burned in a combustion chamber, and the internal combustion engine is operated using power that is generated when the burned fuel expands. An internal combustion engine is provided with a plurality of cylinders. Deactivation of one or more cylinders during low engine load and allowing the remaining cylinders to carry the load increases fuel economy. Such multi-cylinder engines capable of cylinder deactivation have been produced. Typically, in the case of an in-line 4 cylinder engine, two cylinders are deactivated; in the case of a V-6, three cylinders (one bank) are deactivated. Here, “deactivating a cylinder” means inhibiting any of intake of an air/fuel mixture, combustion, and exhaust of combustion gas, while allowing reciprocating motion of a piston.  
           [0003]    Typically, the deactivation of cylinders is performed by an apparatus for disabling the camshaft such that the intake valve is maintained in a closed state. However, cylinder deactivation apparatus according to the prior art require an apparatus for disabling the camshaft, and therefore, manufacturing costs increase.  
         SUMMARY OF THE INVENTION  
         [0004]    In a preferred embodiment of the present invention, an apparatus for deactivating one or more cylinders of an internal combustion engine comprises a surge tank, an air distributor, and an intake manifold. The surge tank inclues a plurality of chambers that temporarily store air provided from a throttle body. The air distributor selectively provides air to the chambers of the surge tank. The intake manifold is connected to the chambers of the surge tank. Preferably, the surge tank is divided into two chambers by a dividing wall, and the air distributor is disposed between the throttle body and the surge tank.  
           [0005]    In a further preferred embodiment, the air distributor comprises a first plate, a second plate, a rotator, and a plurality of air distributing tubes, wherein the first plate is provided with a plurality of openings equidistantly located on a circular line formed at a constant radius from a center thereof. The second plate is rotatably disposed proximate to said first plate, the second plate being provided with a plurality of openings located at positions corresponding to the openings of the first plate and one additional opening located on the circular line midway between any two of the equidistantly located openings. The rotator rotates the second plate, and the plurality of air distributing tubes provide communication between the openings of the first plate and the chambers of the surge tank.  
           [0006]    More preferably, the rotator comprises a rotating rod, a connecting rod, and an actuator. One end portion of the rotating rod is connected to the second plate; the connecting rod is hingedly connected to the other end portion of the rotating rod; and the actuator moves the connecting rod such that the rotating rod rotates. It is preferable that the actuator is a solenoid.  
           [0007]    It is further preferable that the first plate is provided with two openings, and that the second plate is provided with two openings corresponding to the openings of the first plate and one additional opening located midway between the two openings on the circular line formed at a constant radius from the center thereof.  
           [0008]    In a further alternative embodiment of the invention, a housing communicates with an air intake. An air distributing member is disposed in the housing. At least first and second distributing tubes communicate with the housing and with a surge tank. The surge tank is divided into first and second chambers, each chamber communicating with one of the tubes. Each chamber communicates via an intake manifold with a selected number of cylinders less than all cylinders of the engine. Preferably, the air distributing member comprises first and second plates. The first plate defines at least first and second openings, each opening being aligned with one of the distributing tubes. The second plate is disposed between the first plate and the distributing tubes and is rotatable between a first position permitting air flow to all distributing tubes and a second position blocking air flow to at least one distributing tube.  
           [0009]    In a further preferred embodiment, the second plate defines a first set of two openings alignable with the first and second distributing tubes and a second set of one opening rotatably displaced from the first set and alignable with one distributing tube. The apparatus may also comprise a rotating rod secured to the second plate, a connecting rod cooperating with the rotating rod, a connection bar pivotably connected to the connecting rod, and a solenoid acting on the connection bar. Actuation of the solenoid rotates the second plate to a predetermined orientation. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention, and, together with the description, serve to explain the principles of the invention, wherein:  
         [0011]    [0011]FIG. 1 is a schematic view of the cylinder deactivation apparatus according to a preferred embodiment of the present invention;  
         [0012]    [0012]FIG. 2 is a plane view of a rotator of the cylinder deactivation apparatus of FIG. 1;  
         [0013]    [0013]FIG. 3 shows the state of first and second circular plates during full engine load; and  
         [0014]    [0014]FIG. 4 shows the state of first and second circular plates during low engine load. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]    Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.  
         [0016]    As shown in FIG. 1, an air supply system of an internal combustion engine comprises an air cleaner  10 , a throttle body  14  defining a throttle bore where a throttle valve  12  for regulating an amount of intake air is mounted, a surge tank  16  for temporarily storing air provided from the throttle body  14 , and an intake manifold  18  for providing air of the surge tank  16  into combustion chambers (not shown).  
         [0017]    An apparatus for deactivating one or more cylinders according to the invention therefore preferably comprises the surge tank  16 , which is divided into two chambers  16   a  and  16   b  by a dividing wall  20 . Air is respectively provided into the chambers  16   a  and  16   b  from the throttle body  14  through air distributing tubes  22   a  and  22   b.  Also, the intake manifold  18  is connected to the surge tank  16  so that air is supplied to the combustion chambers.  
         [0018]    The cylinder deactivation apparatus according to the present invention further includes an air distributing member for distributing air between chambers  16   a  and  16   b  of the surge tank  16 . The air distributing member includes a first circular plate  24  and a second circular plate  26 . The first circular plate  24  is fixedly mounted to a housing  28 , and the second circular plate  26  is rotatable with respect to the first circular plate  24  and is disposed to closely contact the first circular plate  24 . Two circular holes  24   a  and  24   b  are formed on the first circular plate  24 , as shown in FIGS. 3 and 4.  
         [0019]    The second circular plate  26 , as shown in FIGS. 3 and 4, is provided with three circular holes  26   a,    26   b,  and  26   c.  Positions of the holes  26   a  and  26   b  correspond to positions of the holes  24   a  and  24   b  of the first circular plate  24 , and the hole  26   c  is located on a line perpendicular to a line connecting centers of the holes  24   a  and  24   b  when the second circular plate  26  is in a position for operating all cylinders, at the same distance from the center of the plate as the others.  
         [0020]    If the second circular plate  24  rotates with respect to the first circular plate, the holes  24   a  and  24   b  are selectively opened or closed. The air distributing tubes  22   a  and  22   b  are connected to a lower portion of the housing  28  at positions corresponding to the positions of the holes  24   a  and  24   b  of the first circular plate  24 .  
         [0021]    The second circular plate  26  is closely contacted to the first circular plate  24  such that air does not leak therebetween when air is supplied to the chambers  16   a  and  16   b  of the surge tank  16  through the air distributing tubes  22   a  and  22   b.  The first circular plate  24  is mounted to the housing  28  such that air passing through the throttle body  14  flows into the holes  24   a  and  24   b.    
         [0022]    As shown in FIG. 2, a rotator for rotating the second circular plate  26  comprises a rotating rod  32  with one end fixedly connected to a central axis of the second circular plate  26  through a post  30 , a pair of connecting rods  34   a  and  34   b  that are hingedly connected to a hinge post  33  on the other end of the rotating rod  32 . Solenoids  36   a  and  36   b  are hingedly connected to connecting rods  34   a  and  34   b.  Because the rotating rod  32  is fixed to the central axis of the second circular plate  26  through the post  30 , the second circular plate  26  rotates with the rotating rod  32 .  
         [0023]    The connecting rods  34   a  and  34   b  are connected to the rotating rod  32  such that if one of the connecting rods  34   a  or  34   b  moves more than a certain amount, the rotating rod  32  rotates. That is, the connecting rods  34   a  and  34   b  are provided with slots, and if one of the connecting rods  34   a  or  34   b  moves an amount greater than the length of the slot with respect to the hinge post  33 , the rotating rod  32  rotates.  
         [0024]    The solenoids  36   a  and  36   b  are hingedly connected to the connecting rods  34   a  and  34   b.  When the solenoids are located far from the connecting rods, connecting bars  38  can be disposed between the connecting rods and the solenoids. The solenoids  36   a  and  36   b  are actuated to move the connecting rods  34   a  and  34   b  according to signals indicating engine load.  
         [0025]    Operation of the cylinder deactivation apparatus according to the present invention will be explained hereinafter.  
         [0026]    During full engine-load, the second circular plate  26  is controlled to rotate such that the holes  26   a  and  26   b  of the second circular plate  26  are overlapped with the holes  24   a  and  24   b  of the first circular plate  24 , as shown in FIG. 3. Thus, air is supplied to both the chambers  16   a  and  16   b  of the surge tank  16  through the holes  24   a,    24   b,    26   a,  and  26   b,  and the air distributing tubes  22   a  and  22   b.  The air supplied to the chambers  16   a  and  16   b  is supplied to all combustion chambers through the intake manifold  18 . All cylinders are then activated.  
         [0027]    During low engine load, current is applied to only one of the solenoids  36   a  and  36   b.  If current is supplied to solenoid  36   b  and not to solenoid  36   a,  the connecting rod  34   b  is pulled by the solenoid action, and it slides along its slot on the hinge post  33  of the rotating rod  32 . Once the end of the slot of the connecting rod  34   b  reaches the hinge post  33  of the rotating rod  32 , continued pulling of the solenoid causes the rotating rod  32  to rotate. Therefore, the second circular plate  26  that is fixed to the rotating rod  32  through the post  30  rotates to a position as shown in FIG. 4.  
         [0028]    As the connecting rod  34   b  causes the rotating rod  32  to rotate, the connecting rod  34   a  pivots at its hinge point with the solenoid  36   a  as the hinge post  33  moves along the slot of the connecting rod  34   a.    
         [0029]    When the second circular plate  26  is rotated to a point as shown in FIG. 4, air is supplied to the chamber  16   a  of the surge tank  16  through the air distributing tube  22   a  and the circular holes  24   a  and  26   c.  The air distributing tube  22   b  is closed by the second circular plate  26 . Therefore, cylinders connected to the chamber  16   a  of the surge tank  16  are provided with air, and cylinders connected to the chamber  16   b  of the surge tank  16  are not provided with air and are therefore deactivated.  
         [0030]    If a current is applied only to solenoid  36   a,  the second circular plate  26  rotates in a direction opposite to the direction resulting in the alignment of FIG. 4. In this case, air is supplied to the chamber  16   b  through the air distributing tube  22   b  and the circular holes  24   b  and  26 c. The air distributing tube  22   a  is closed by the second circular plate  26 . Therefore, cylinders connected to the chamber  16   b  of the surge tank  16  are provided with air, and cylinders connected to the chamber  16   a  of the surge tank  16  are not provided with air and are therefore deactivated.  
         [0031]    It is preferable that fuel is not injected into the cylinders to which air is not supplied.  
         [0032]    As stated above, the cylinder deactivation apparatus according to the present invention can deactivate one or more of cylinders without an apparatus for disabling a camshaft. Therefore, the manufacturing costs decrease and the manufacturing process can be simplified.  
         [0033]    Further, because opening/closing valve timing control, which has a serious affect on efficiency of an internal combustion engine, is not needed, the internal combustion engine can be optimally controlled while deactivating cylinders.