Abstract:
An engine system having a coolant control valve includes a coolant pump pumps a coolant. A cylinder head receives the coolant by a first exhaust side water jacket and discharges the received coolant to a first intake side water jacket. An intake cylinder block receives the coolant by a second exhaust side water jacket and discharges the received coolant to a second intake side water jacket. A coolant control valve selectively blocks the coolant discharged from the first intake side water jacket of the cylinder head and the coolant discharged from the second intake side water jacket of the cylinder block, and separately controls coolants supplied to at least two heat exchangers. The heat exchangers include an oil cooler cooling oil, an exhaust gas recirculation (EGR) cooler cooling a recirculation exhaust gas, a heater core for indoor heating, or a radiator releasing heat of the coolant to outside.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims the benefit of priority to Korean Patent Application Number 10-2014-0166800 filed on Nov. 26, 2014, the entire contents of which application are incorporated herein for all purposes by this reference. 
       TECHNICAL FIELD 
       [0002]    The present disclosure relates to an engine system having a coolant control valve capable of enhancing overall cooling efficiency and reducing fuel consumption by controlling a coolant flowing in an exhaust side and an intake side of a cylinder block and a cylinder head, respectively. 
       BACKGROUND 
       [0003]    An engine generates rotary power by combustion of fuel and discharges exhaust gas as thermal energy. In particular, a coolant, absorbs thermal energy and discharges the absorbed thermal energy while circulating through an engine, a heater, and a radiator. 
         [0004]    When a temperature of the engine coolant is low, viscosity of oil may increase, thus increasing frictional force and fuel consumption. A temperature of the exhaust gas may increase gradually to lengthen a time to activate a catalyst and degrade quality of the exhaust gas. In addition, a time required for the heater to be normalized increases. 
         [0005]    If the temperature of the coolant is too high, knocking is generated, and ignition timing needs to be adjusted to suppress generation of knocking, thus degrading performance. If a temperature of a lubricant is too high, a lubricating operation may be degraded. 
         [0006]    Thus, a single coolant control valve is applied to control several cooling elements such that a temperature of the coolant in a particular portion is maintained to be high and a temperature of the coolant in another portion is maintained to be low. 
         [0007]    Among the several cooling elements, a technique of separately cooling a cylinder block and a cylinder head has been researched. 
         [0008]    The cylinder block and the cylinder head have an intake side for taking in ambient air having a relatively low temperature and an exhaust side for discharging the exhaust gas having a relatively high temperature, and studies have been conducted to uniformly control temperatures of the exhaust side and the intake side to enhance cooling efficiency and to reduce fuel consumption. 
         [0009]    The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
       SUMMARY 
       [0010]    The present disclosure has been made in an effort to provide an engine system having a coolant control valve having advantages of enhancing overall cooling efficiency of an engine and reducing fuel consumption by separately cooling a cylinder head and a cylinder block and uniformly cooling an intake side and an exhaust side of the cylinder head and the cylinder block. 
         [0011]    An exemplary embodiment of the present inventive concept, an engine system having a coolant control valve includes a coolant pump that pumps a coolant. A cylinder head receives the coolant pumped by the coolant pump by a first exhaust side water jacket and discharges the received coolant to a first intake side water jacket. An intake cylinder block receives the coolant pumped by the coolant pump by a second exhaust side water jacket and discharges the received coolant to a second intake side water jacket. A coolant control valve selectively blocks the coolant discharged from the first intake side water jacket of the cylinder head and the coolant discharged from the second intake side water jacket of the cylinder block, and separately controls coolants supplied to at least two heat exchangers. The heat exchangers include an oil cooler cooling oil, an exhaust gas recirculation (EGR) cooler cooling a recirculation exhaust gas, a heater core for indoor heating, or a radiator releasing heat of the coolant to outside. 
         [0012]    The coolant supplied to the first exhaust side water jacket of the cylinder head may flow to the first intake side water jacket, while flowing along the first exhaust side water jacket. 
         [0013]    The coolant supplied to the second exhaust side water jacket of the cylinder block may flow to the second intake side water jacket, while flowing along the second exhaust side water jacket. 
         [0014]    A first throttle bar may be installed on a coolant entrance side within the cylinder head in order to prevent the coolant introduced to the first exhaust side water jacket from flowing to the first intake side water jacket. 
         [0015]    A second throttle bar may be installed on a coolant entrance side within the cylinder block in order to prevent the coolant introduced to the second exhaust side water jacket from flowing to the second intake side water jacket. The coolant control valve may include a cylindrical valve having a pipe shape with a space formed therein and coolant passages connected from the space to an outer side surface. A valve housing has an inner circumferential surface corresponding to an outer circumferential surface of the cylindrical valve, rotating the cylindrical valve with respect to a central axis, and having connection pipes formed to be connected to the heat exchangers, corresponding to the coolant passages. A driving unit is configured to rotate the cylindrical valve such that the coolant passages and the connection pipes respectively correspond to each other. 
         [0016]    The engine system may further include sealing members interposed between the cylindrical valve and the valve housing such that the sealing members correspond to the connection pipes to seal the coolant. 
         [0017]    The connection pipes may include a first connection pipe connected to the first intake side water jacket of the cylinder head to receive a coolant. A second connection pipe is connected to the EGR cooler and the heater core to supply a coolant. A third connection pipe is connected to the radiator to supply the coolant. A fourth connection pipe is connected to the second intake side water jacket of the cylinder block to receive the coolant. A fifth connection pipe is connected to the oil cooler to supply a coolant. 
         [0018]    According to an embodiment of the present inventive concept, a coolant is supplied to the exhaust side of the cylinder head, the coolant is discharged to the intake side of the cylinder head, a coolant is supplied to the exhaust side of the cylinder block, the coolant is discharged to the intake side of the cylinder block, and the coolants discharged from the intake side of the cylinder head and from the intake side of the cylinder block are separately controlled, whereby a temperature of the engine is uniformly maintained overall, thus enhancing fuel efficiency and reducing fuel consumption. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a flowchart illustrating an overall flow of a coolant in an engine system having a coolant control valve according to an exemplary embodiment of the present inventive concept. 
           [0020]      FIG. 2  is a partial schematic perspective view of the coolant control valve according to an exemplary embodiment of the present inventive concept. 
           [0021]      FIG. 3  is a partial cross-sectional view of an engine according to an exemplary embodiment of the present inventive concept. 
           [0022]      FIG. 4  is a perspective view illustrating a water jacket formed within a cylinder head and a cylinder block of the engine according to an exemplary embodiment of the present inventive concept. 
           [0023]      FIG. 5  is a partial cross-sectional view of the coolant control valve related to the present inventive concept. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0024]    An exemplary embodiment of the present inventive concept will hereinafter be described in detail with reference to the accompanying drawings. 
         [0025]      FIG. 1  is a flowchart illustrating an overall flow of a coolant in an engine system having a coolant control valve according to an exemplary embodiment of the present inventive concept. 
         [0026]    Referring to  FIG. 1 , an engine system includes a coolant pump  100 , a cylinder head  110 , a cylinder block  120 , a coolant control valve  130 , and at least two heat exchangers including a radiator  140 , an oil cooler  150 , a heater core  170 , and an exhaust gas recirculation (EGR) cooler  160 . 
         [0027]    The cylinder head  110  includes a first intake side water jacket  112  formed on an intake side and a first exhaust side water jacket  114  formed on an exhaust side. The cylinder block  120  includes a second intake side water jacket  122  formed on an intake side and a second exhaust side water jacket  124  formed on an exhaust side 
         [0028]    The coolant pump  100  supplies a coolant to the first exhaust side water jacket  114  of the cylinder head  110 , and the coolant supplied to the first exhaust side water jacket  114  flows from the first exhaust side water jacket  114  to the first intake side water jacket  112 . The coolant is delivered from the first intake side water jacket  112  to the coolant control valve  130 . 
         [0029]    In addition, the coolant pump  100  supplies the coolant to the second exhaust side water jacket  124  of the cylinder block  120 , and the coolant supplied to the second exhaust side water jacket  124  flows from the second exhaust side water jacket  124  to the second intake side water jacket  122 . The coolant is delivered from the second intake side water jacket  122  to the coolant control valve  130 . 
         [0030]    The coolant supplied to the coolant control valve  130  is distributed to the heater core  170 , the EGR cooler  160 , the radiator  140 , or the oil cooler  150  along coolant lines. The coolant which has passed through the heater core  170 , the coolant which has passed through the EGR cooler  160 , the coolant which has passed through the oil cooler  150 , and the coolant which has passed through the radiator  140  circulate to an intake side of the coolant pump  100 . 
         [0031]    The heater core  170  serves to heat an indoor space of a vehicle using the circulating warm coolant, the EGR cooler  160  serves to cool a recirculation exhaust gas recirculating from an exhaust line to an intake line, the radiator  140  serves to outwardly discharge heat of the coolant, and the oil cooler  150  serves to cool oil circulating the cylinder head  110  or the cylinder block  120 . 
         [0032]    In an exemplary embodiment of the present inventive concept, a coolant supplied to one end portion of the first exhaust side water jacket  114  flows to another end portion of the first exhaust side water jacket  114 , and here, the coolant flows from the first exhaust side water jacket  114  to the first intake side water jacket  112  in a width direction of the cylinder head  110 . 
         [0033]    A coolant supplied to one end portion of the second exhaust side water jacket  124  flows to another end of the second exhaust side water jacket  124 , and here, the coolant flows from the second exhaust side water jacket  124  to the second intake side water jacket  122  in a width direction of the cylinder block  120 . 
         [0034]    In general, in the cylinder head  110  and the cylinder block  120 , the exhaust side has a relatively high temperature distribution, and the intake side has a relatively low temperature distribution. Thus, the cylinder head  110  and the cylinder block  120  can be separately cooled, and the exhaust sides and intake sides of the cylinder head  110  and the cylinder block  120  can be sequentially cooled. 
         [0035]    Since the cylinder head  110  and the cylinder block  120  are separately cooled and the intake sides and the exhaust sides thereof are uniformly cooled, combustion efficiency may be enhanced and the temperature distributions of the cylinder head  110  and the cylinder block  120  may become uniform, reducing frictional resistance of oil to reduce fuel consumption. 
         [0036]      FIG. 2  is a partial schematic perspective view of the coolant control valve according to an exemplary embodiment of the present inventive concept.  FIG. 3  is a partial cross-sectional view of an engine according to an exemplary embodiment of the present inventive concept. 
         [0037]    Referring to  FIGS. 2 and 3 , the coolant control valve  130  includes a cylindrical valve  320 , a valve housing  302 , a rotational shaft  315 , a sealing member  324 , a first connection pipe  252 , a second connection pipe  256 , a third connection pipe  258 , a fourth connection pipe  254 , a fifth connection pipe  260 , and a motor housing  300 . 
         [0038]    The cylindrical valve  320  has a pipe structure with a space formed therein and coolant passages  321  formed at preset positions to be connected from the space to an outer side surface. An inner circumferential surface of the valve housing  302  corresponds to an outer circumferential surface of the cylindrical valve  320 , and the cylindrical valve  320  is rotatably disposed within the valve housing  302 . 
         [0039]    The motor housing  300  is disposed on one side of the valve housing  302 , and a motor installed within the motor housing  300  is disposed to rotate the cylindrical valve  320  through the rotational shaft  315 . 
         [0040]    As illustrated, four coolant passages  321  are disposed in set positions in the cylindrical valve  320 , the first connection pipe  252 , the second connection pipe  256 , the third connection pipe  258 , the fourth connection pipe  254 , and the fifth connection pipe  260  are connected to the valve housing  302 , and sealing members  324  are interposed between the valve housing  302  and the cylindrical valve  320  such that the sealing members  324  correspond to connection pipes  252 ,  256 ,  258 ,  254 , and  260 , respectively. 
         [0041]    The first connection pipe  252  is connected to the first intake side water jacket  112  of the cylinder head  110  to receive a coolant, the fourth connection pipe  254  is connected to the second intake side water jacket  122  of the cylinder block  120  to receive a coolant, and the coolant supplied to the first connection pipe  252  and the second connection pipe  256  is supplied through the coolant passages  321  of the cylindrical valve  320 . 
         [0042]    The second connection pipe  256  is connected to the EGR cooler  160  and the heater core  170 , and supplies the coolant supplied to an inner side of the cylindrical valve  320  to the EGR cooler  160  and the heater cover  170  through the coolant passages  321 . 
         [0043]    The third connection pipe  258  is connected to the radiator  140  to supply the coolant supplied to the inner side of the cylindrical valve  320  to the radiator  140  through the coolant passage  321 , and the fifth connection pipe  260  is connected to the oil cooler  150  to supply the coolant supplied to the inner side of the cylindrical valve  320  to the oil cooler  150  through the coolant passage  321 . 
         [0044]    In an exemplary embodiment of the present inventive concept, the coolant control valve  130  may block the coolant supplied to the cylinder head  110  and the cylinder block  120  according to rotational positions of the cylindrical valve  320  in a state in which the coolant is cold, thus maintaining a zero flow state. 
         [0045]    In addition, when the coolant is overheated, the coolant control valve  130  may not block the coolant supplied from the cylinder head  110  and the cylinder block  120  and may circulate the coolant to the EGR cooler  160 , the heater core  170 , the radiator  140 , and the oil cooler  150  according to rotational positions of the cylindrical valve  320 . 
         [0046]    According to the rotational positions of the cylindrical valve  320 , the coolant control valve  130  may block the coolant supplied to the EGR cooler  160  and the heater core  170 , block the coolant supplied to the radiator  140 , and block the coolant supplied to the oil cooler  150 . 
         [0047]    Further, the cylinder head  110  includes an intake side on which an intake port is formed and an exhaust side on which an exhaust port is formed. The cylinder block  120  also includes an intake side and an exhaust side. In addition, the coolant pump  100  may be disposed in one end portion of the cylinder block  120 , and the coolant control valve  130  may be disposed in the other portion of the cylinder block  120 . 
         [0048]      FIG. 4  is a perspective view illustrating a water jacket formed within a cylinder head and a cylinder block of the engine according to an exemplary embodiment of the present inventive concept. 
         [0049]    Referring to  FIG. 4 , the first intake side water jacket  112  is formed within the cylinder head  110  to correspond to the intake side, and the first exhaust side water jacket  114  corresponds to the exhaust side. The first intake side water jacket  112  and the first exhaust side water jacket  114  may be configured as one body, and may be divided with respect to a central axis  420  of the cylinder head  110  in a length direction. 
         [0050]    In addition, a first throttle bar  412  may be installed in the first intake side water jacket  112  in order to prevent the coolant supplied to the first exhaust side water jacket  114  from flowing to the first intake side water jacket  112 . 
         [0051]    The first throttle bar  412  is disposed on one side of a corner leading to the first intake side water jacket  112  from the first exhaust side water jacket  114 , to allow the coolant to uniformly flow from the first exhaust side water jacket  114  to the first intake side water jacket  112  overall. 
         [0052]    Referring to  FIG. 4 , a coolant jacket has the cylinder block  120  to correspond to each cylinder, and the coolant jacket includes a second intake side water jacket  122  corresponding to the intake side and a second exhaust side water jacket  124  corresponding to the exhaust side. 
         [0053]    The second intake side water jacket  122  and the second exhaust side water jacket  124  may a single body, and may be divided with respect to the central axis  420  of the cylinder block  120  in the length direction. 
         [0054]    In addition, a second throttle bar  410  may be installed in the second intake side water jacket  122  in order to prevent the coolant supplied to the second exhaust side water jacket  124  from flowing in quantity to the second intake side water jacket  122 . 
         [0055]    The second throttle bar  410  is disposed on one side of a corner leading to the second intake side water jacket  122  from the second exhaust side water jacket  124 , to allow the coolant to uniformly flow from the second exhaust side water jacket  124  to the second intake side water jacket  122  overall. 
         [0056]    A bridge passage  405  is formed in the middle of each cylinder to connect the second exhaust side water jacket  124  and the second intake side water jacket  122 , and cools the narrow space in the cylinder. 
         [0057]      FIG. 5  is a partial cross-sectional view of the coolant control valve related to the present disclosure. 
         [0058]    Referring to  FIG. 5 , the coolant control valve  130  includes the motor housing  300  in which the motor is installed, an output gear  305  rotated by the motor, and a passive gear  310  rotated by the output gear  305 . The passive gear  310  rotates the cylindrical valve  320 . 
         [0059]    The cylindrical valve  320  has a pipe shape with both ends opened, and has a space formed in a central portion thereof in a length direction. A coolant passage  321  from the space of the central portion to an outer surface is formed in the cylindrical valve  320 . 
         [0060]    In the valve housing  302  in which the cylindrical valve  320  is installed, a first entrance pipe  325  is disposed in one end portion and the motor housing  300  is connected to another end portion thereof. In the valve housing  302 , a radiator supply pipe  340  connected to the radiator  140 , a second entrance pipe  330  connected to the cylinder head  110 , and a heater supply pipe  335  connected to the heater are disposed. 
         [0061]    A sealing member  324  is disposed on an outer circumferential surface of the cylindrical valve  320 , a front end portion of the radiator supply pipe  340  is inserted into the sealing member  324 , and an elastic member  326  elastically pushes the sealing member  324  toward an outer circumferential surface of the cylindrical valve  320  to form a sealing structure. 
         [0062]    A controller (not shown) controls the motor within the motor housing  300  according to operation conditions, namely, a coolant temperature, an intake temperature, and the like, to rotate the cylindrical valve  320  with respect to the rotational shaft  315  disposed along the central axis of the cylindrical valve  320  in the length direction through the output gear  305  and the passive gear  310 . 
         [0063]    When the passages  321  of the cylindrical valve  320  correspond to the first entrance pipe  325  or the second entrance pipe  330 , the coolant is supplied. 
         [0064]    While this disclosure has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.