Abstract:
The present disclosure provides a cylinder deactivation engine which is configured to prevent abrasion on a pad portion of a valve opening/closing unit and improves reliability of the cylinder deactivation. The cylinder deactivation engine selectively performing deactivation of a cylinder may include: a cylinder deactivation apparatus including an inner body which contacts with a cam formed at a camshaft and makes a lever motion by rotation of the camshaft; and an outer body which moves together with the inner body by selectively latching to the inner body so as to open/close a valve; and a stopper integrally formed with a cam carrier disposed to surround a part of a lower portion of the camshaft and disposed between the camshaft and the outer body so as to function as a stopper for blocking the outer body which is pushed toward the camshaft by the valve.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of Korean Patent Application No. 10-2015-0083555, filed on Jun. 12, 2015, which is hereby incorporated by reference in its entirety. 
     FIELD 
     The present disclosure relates to a cylinder deactivation engine. 
     BACKGROUND 
     The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
     Generally, an internal combustion engine is an apparatus that operates using energy from heat generated by burning a gas mixture in a combustion chamber. As an internal combustion engine, a multi-cylinder engine with a plurality of cylinders for increasing power and reducing noise and vibration is generally used. 
     Recently, a cylinder deactivation apparatus of an engine that improves fuel efficiency by deactivating some of a plurality of cylinders in an engine when the engine generates a small amount of power has been developed with the increase in energy cost. 
     A way of deactivating cylinders used by such a cylinder deactivation apparatus is to operate an engine by injecting and burning a gas mixture in only some of the plurality of cylinders without injecting and igniting a gas mixture in the other cylinders. 
     For example, for a four-cylinder engine, the apparatus does not inject and ignite a gas mixture in two cylinders and operates the engine with only the other two cylinders. 
     Meanwhile, a variable valve lift technique that selectively implements a zero lift of a valve so that a gas mixture is not injected may be applied to deactivated cylinders. 
     However, abrasion of the pad portion may be occurred when a pad portion of a valve opening/closing unit is in rolling-contact with a zero cam or a camshaft to realize zero lift of a valve. Durability of the valve opening/closing unit may be deteriorated if the pad portion of the valve opening/closing unit is worn. In addition, if the pad portion is worn, reliability about cylinder deactivation may be deteriorated as the valve opening/closing unit makes a lever motion depending on rotation of a cam even while the valve opening/closing unit is operated so as to realize the zero lift of the valve. 
     SUMMARY 
     The present disclosure provides a cylinder deactivation engine having advantages of reducing or preventing abrasion on a pad portion of a valve opening/closing unit and providing reliability about the cylinder deactivation. 
     A cylinder deactivation engine according to an exemplary embodiment of the present disclosure which selectively perform deactivation of a cylinder may include: a cylinder deactivation apparatus including an inner body which contacts with a cam formed at a camshaft and makes a lever motion by rotation of the camshaft, and an outer body which moves together with the inner body by selectively latching to the inner body so as to open/close a valve; and a stopper integrally formed with a cam carrier disposed to surround a part of a lower portion of the camshaft and disposed between the camshaft and the outer body so as to function as a protrusion for blocking the outer body which is pushed toward the camshaft by the valve. 
     The outer body may make a lever motion together with the inner body by latching to the inner body such that normal lift of the valve is performed, and the outer body may do not make a lever motion by releasing from the inner body such that zero lift of the valve is performed. 
     A part of an upper portion of the outer body to face the camshaft may be contacted to the stopper when zero lift of the valve is performed. 
     The cam carrier may be disposed apart from the cam by a predetermined distance along an axial direction, and the stopper may be protruded from the cam carrier toward the cam along an axial direction. 
     Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which: 
         FIG. 1  is a top plan view of a cylinder deactivation apparatus according to an exemplary embodiment of the present disclosure; 
         FIG. 2  is a cross sectional side view of a cylinder deactivation apparatus according to an exemplary embodiment of the present disclosure; and 
         FIG. 3  is a partial cross-sectional view a cylinder deactivation engine according to an exemplary embodiment of the present disclosure. 
     
    
    
     DESCRIPTION OF SYMBOLS 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 100: cylinder deactivation apparatus 
                 110: outer body 
               
               
                 112: outer body inside space 
                 114: outer connecting portion 
               
               
                 115: pad portion 
                 116: valve contact portion 
               
               
                 119: lever motion pivot shaft 
               
               
                 120: inner body 
                 122: inner connecting portion 
               
               
                 124: inner body inside space 
                 129: latching pin hole 
               
               
                 130: roller 
                 135: roller rotation shaft 
               
               
                 140: connecting shaft 
               
               
                 150: lost motion spring 
               
               
                 160: latching pin 
                 165: latching spring 
               
               
                 167: latching pin stopper 
                 169: hydraulic pressure chamber 
               
               
                 200: camshaft 
                 202: normal cam 
               
               
                 204: zero cam 
                 210: cam cap 
               
               
                 220: cam carrier 
                 225: pad portion stopper 
               
               
                   
               
             
          
         
       
     
     The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
       FIG. 1  is a top plan view of a cylinder deactivation apparatus according to an exemplary embodiment of the present disclosure. 
     As shown in  FIG. 1 , a cylinder deactivation apparatus  100  according to an exemplary embodiment of the present disclosure includes an outer body  110 , an inner body  120 , a roller  130 , a connecting shaft  140 , and a lost motion spring  150 . In addition, the cylinder deactivation apparatus  100  is a valve opening/closing unit which is operated so as to selectively realize zero lift of a valve. 
     The outer body  110  selectively receives torque of a camshaft  200  ( FIG. 3 ) so as to make a lever motion, and operates to open/close the valve by the lever motion. In addition, a normal cam  202  is formed or disposed at the camshaft  200  so as to transform a rotational motion of the camshaft  200  to the lever motion of the outer body  110 . Herein, the valve is an intake valve or an exhaust valve of an engine. Further, a space  112 , that the outer body  110  is penetrated in a vertical direction, is formed inside of the outer body  110 . That is, the outer body  110  has a set length so as to make a lever motion, and has a set width and a set thickness so as to form the inside space  112  of the outer body  110 . 
     The valve is connected to a first end  111  of the outer body  110 , and a lever motion pivot shaft  119  is disposed at the other second end  133  thereof, opposite the first end  111 . In addition, the inside space  112  of the outer body  110  is opened toward the first end  111  of the outer body  110  such that an entire shape of the outer body  110  is formed in a “U” shape. 
     In description hereinafter, the first end  111  and the second end  113  of each elements which are connected to or disposed at the outer body  110  mean a portion on the same side with the first end  11  and the second end  113  of the outer body  110 . 
     The inner body  120  is disposed in the inside space  112  of the outer body  110 . In addition, one end of the inner body  120  is rotatably connected with the first end  111  of the outer body  110  by connecting shaft  140 . Further, the inner body  120  makes a lever motion according to torque of the camshaft  200 , and operates to selectively open/close the valve. A space  124  that the inner body  120  is penetrated in a vertical direction is formed inside of the inner body  120 . That is, the inner body  120  has a set length so as to make a lever motion, and has a set width and a set thickness so as to form the inside space  124  of the inner body  120 . 
     The roller  130  is disposed in the inside space  124  of the inner body  120 . In addition, the roller  130  is rotatably connected with the inner body  120 . Meanwhile, a roller rotation shaft  135  is provided so as to rotatably connect the roller  130  with the inner body  120 . That is, the roller  130  rotates around the roller rotation shaft  135 . Further, the roller  130  is in rolling-contact with the normal cam  202  so as to transform a rotational motion of the camshaft  200  to a lever motion of the outer body  110  or the inner body  120 , as best seen in  FIGS. 2 and 3 . 
     The connecting shaft  140  is provided so as to rotatably connect the first end  111  of the outer body  110  with the one end of the inner body  120 . That is, the inner body  120  is relatively rotated with the outer body  110  around the connecting shaft  140 . Herein, portion of the outer body  110  which is connected with the inner body  120  by the connecting shaft  140  will be called “outer connecting portion  114 ”, and portion of the inner body  120  which is connected with the outer body  110  by the connecting shaft  140  will be called “inner connecting portion  122 ”. 
     A valve contact portion  116  is formed or disposed at the first end  111  of the outer body  110  to be positioned near the outer connecting portion  114 .  FIG. 1  shows that the outer connecting portions  114  are formed as two spaced apart portions or flanges of the outer body  110 , but it is not limited thereto. In case the outer connecting portion  114  is formed as two portions or flanges, the valve contact portions  116  may be formed or disposed as two portions or flanges that are spaced apart and positioned near each of the two outer connecting portions  114 . In addition, the two valve contact portions  116  are contacted with the valve so as to push two valves, which are disposed at one cylinder (not shown), depending on the lever motion of the outer body  110 . 
     The inner body  120  is selectively latched to the outer body  110  so as to make a lever motion together with the outer body  110 , or is selectively released from the outer body  110  so as to independently make a lever motion. 
     The lost motion spring  150  functions to return the inner body  120  which makes a rotation relative to the outer body  110  by the independent lever motion in case the inner body  120  latched the outer body  110  is released. 
       FIG. 2  is a cross sectional side view of a cylinder deactivation apparatus according to an exemplary embodiment of the present disclosure. 
     As shown in  FIG. 2 , the inner body  120  further includes a latching pin hole  129 , while a latching pin  160 , a latching pin stopper  167  and a latching spring  165  are disposed at the outer body  110 . 
     The latching pin hole  129  is a hole to be formed such that a latching pin  160  is inserted thereinto. The latching pin  160  is operated by hydraulic pressure, and may be disposed at the second end  113  side of the outer body  110  so as to easily receive hydraulic pressure. Meanwhile, a member such as a hydraulic lash adjuster (HLA) for supplying hydraulic pressure may be mounted at the second end  113  side of the outer body  110 . 
     The latching pin stopper  167  is provided to prevent that the latching pin  160  is escaped toward the other end direction of the outer body  110 . 
     The latching pin  160  is inserted into the latching pin hole  129  by elastic force of the latching spring  165  such that the inner body  120  may be latched to the outer body  110 . That is, the latching spring  165  is a spring which is disposed between the latching pin stopper  167  and the latching pin  160  such that one end of the latching spring  165  pushes the latching pin  160  toward the inner body  120 . In addition, a hydraulic pressure chamber  169  which is surrounded by the outer body  110  and the latching pin  160  is formed at the one end side of the latching pin  160 . Further, the latching pin  160  is pushed toward the other end direction of the outer body  110  by hydraulic pressure supplied to the hydraulic pressure chamber  169  such that the inner body  120  is released from the outer body  110 . In other words, the latching pin  160  is returned by the latching spring  165  so as to be inserted into the latching pin hole  129  such that the inner body  120  is fixed to the outer body  110  in case that hydraulic pressure supplied to the hydraulic pressure chamber  169  is released. Latching and releasing of the outer body  110  and the inner body  120  may be variously realized depending on design change by a person of ordinary skill in the art. 
     When the inner body  120  is latched to the outer body  110 , the inner body  120  and the outer body  110  make a lever motion together around the lever motion pivot shaft  119  of the outer body  110  by rotation of the normal cam  202  in rolling-contact with the roller  130 . In addition, when the inner body  120  is released from the outer body  110 , only the inner body  120  makes a lever motion around the connecting shaft  140  by rotation of the normal cam  202  in rolling-contact with the roller  130 . 
     Herein, normal lift of the valve may be realized by the outer body  110  which makes a lever motion together with the inner body  120 , and zero lift of the valve may be realized as the outer body  110  does not make a lever motion during a lever motion made by only the inner body  120 . Thus, the deactivation of the cylinder can be selectively performed. 
       FIG. 3  is a partial cross-sectional view a cylinder deactivation engine according to an exemplary embodiment of the present disclosure. 
     A pad portion  115  is formed at the outer body  110  as shown in  FIG. 1  to  FIG. 3 , and the a cylinder deactivation engine according to an exemplary embodiment of the present disclosure includes a pad portion stopper  225  as shown in  FIG. 2  to  FIG. 3 . 
     The pad portion  115  is a part of an upper portion of the outer body  110  to face the camshaft  200 . 
     The camshaft  200 , at which the normal cam  202  is formed or provided, is disposed so as to be not escaped by coupling a cam cap  210  with a cam carrier  220 . Herein, the cam cap  210  which surrounds the part of the upper portion of the camshaft  200  and the cam carrier  220  which surrounds a part of a lower portion of the camshaft  200  are well-known to a person of an ordinary skill in the art, so a detailed description thereof will be omitted. 
     The cam cap  210  and the cam carrier  220  are disposed apart from the normal cam  202  along an axial direction. In addition, a zero cam  204  is formed or disposed between the portions where the cam cap  210  and the cam carrier  220  are coupled, and the normal cam  202  is formed on the camshaft  200 . Herein, the zero cam  204  may be an exterior circumference of the camshaft  200 . 
     Conventionally, the zero cam  204  is in rolling-contact with the pad portion  115  of the outer body  110  when zero lift of a valve is performed, but a cylinder deactivation engine according to an exemplary embodiment of the present disclosure inhibits or prevents that the pad portion  115  contacts with the zero cam  204 . 
     The pad portion stopper  225  functions as a stopper blocking the outer body  110  being pushed toward the camshaft  200  by the valve. In addition, the pad portion stopper  225  is integrally formed with the cam carrier  220 , and is disposed between the camshaft  200  and the outer body  110 . That is, the pad portion stopper  225  is protruded from the cam carrier  220  toward the normal cam  202  along an axial direction, and is protruded to a space between the zero cam  204  and the pad portion  115 . Therefore, when zero lift of the valve is performed, the pad portion  115  is contacted to the pad portion stopper  225 . 
     As the pad portion stopper  225  is integrally formed with the cam carrier  220  which does not rotate, abrasion on the pad portion  115  being contacted to the pad portion stopper  225  may be prevented. 
     According to an exemplary embodiment of the present disclosure, abrasion of the pad portion  115  can be prevented and durability of the cylinder deactivation apparatus  100  can be improved as the pad portion  115  of the cylinder deactivation apparatus  100  is not directly in rolling-contact to the camshaft  200 . Further, reliability of cylinder deactivation can be improved as malfunction of the cylinder deactivation apparatus  100  is reduced under the zero lift condition. 
     This present disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.