Abstract:
An engine system having a control valve may include a multi flow rate control valve that circulates a coolant supplied a side of the multi flow rate control valve to at least two heat exchangers, a pressure cap that is connected to a supply line, which connects the multi flow rate control valve to the at least two heat exchangers, and is operated by a pressure that is transferred from the supply line to release the pressure or exhaust the coolant through an outlet, a reservoir tank that is mounted at one side of the pressure cap and is formed to house the coolant exhausted from the pressure cap, and a connection line that connects the outlet with the reservoir tank to release the pressure from the pressure cap or exhaust the coolant from the pressure cap.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority of Korean Patent Application Number 10-2014-0073081 filed on Jun. 16, 2014, the entire contents of which application are incorporated herein for all purposes by this reference. 
       BACKGROUND OF INVENTION 
       [0002]    1. Field of Invention 
         [0003]    The present invention relates to an engine system having a multi flow rate control valve that respectively controls coolant passing an engine, a radiator, a heater core, and an EGR cooler to be able to improve cooling efficiency and fuel consumption efficiency. 
         [0004]    2. Description of Related Art 
         [0005]    The engine generates a torque by burning fuel, and exhausts the remainder in thermal energy. Particularly, cooling water absorbs heat while circulating the engine, a heater and a radiator and dissipates the heat to an outside of the engine. 
         [0006]    If a cooling water temperature of the engine is low to elevate oil viscosity, it is a trend that friction force and fuel consumption increases and a temperature of exhaust gas rises slowly resulting to prolong a time period of catalyst activation to make a quality of the exhaust gas poor. Along with this, there is a trend that a time period for bringing a heater function to a normal level takes a long time to make occupants and a driver to feel cold. 
         [0007]    If the cooling water temperature of the engine is excessive, knocking takes place, and, if ignition timing is adjusted for suppressing the knocking, performance is liable to become poor. And, if a lubrication oil temperature is excessive, a lubrication action is liable to become poor. 
         [0008]    Accordingly, a temperature of a specific section of an engine is maintained to be high and that of other section of the engine is maintained to be low, wherein one integrated flow rate valve is used to control several cooling elements. 
         [0009]    Particularly, a pressure cap is disposed at an upper end of the radiator, the pressure cap controls the coolant pressure of the cooling system, and the coolant is supplemented through the pressure cap. However, because one integrated flow rate valve is used to control coolant that is supplied to a heater core, an EGR cooler, and a radiator, it is hard to quickly control the pressure of the coolant and it is hard to quickly supplement the coolant. 
         [0010]    The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
       SUMMARY OF INVENTION 
       [0011]    The present invention has been made in an effort to provide an engine system having a multi flow rate control valve having advantages of quickly controlling pressure of coolant line and quickly supplementing coolant, when controlling coolant that is supplied to heat exchanger for cooling and heating through a multi flow rate control valve. 
         [0012]    An engine system having a control valve according to various aspects of the present invention may include a multi flow rate control valve that circulates a coolant supplied a side of the multi flow rate control valve to at least two heat exchangers, a pressure cap that is connected to a supply line, which connects the multi flow rate control valve to the at least two heat exchangers, and is operated by a pressure that is transferred from the supply line to release the pressure or exhaust the coolant through an outlet, a reservoir tank that is mounted at one side of the pressure cap and is formed to house the coolant exhausted from the pressure cap, and a connection line that connects the outlet with the reservoir tank to release the pressure from the pressure cap or exhaust the coolant from the pressure cap. 
         [0013]    A heat exchanger in the at least two heat exchangers may include a heater core that is configured to increase interior air temperature by heating outside air, an EGR cooler that is configured to cool EGR gas recirculated from an exhaust line to an intake line, or a radiator that is configured to cool the coolant by exchanging heat with the outside air. 
         [0014]    The multi flow rate control valve may include a valve housing that is formed with a mounting space, a cylindrical valve that is rotatably disposed in the mounting space, and has a space formed in a central portion of the cylindrical valve and in a length direction of the cylindrical valve, and a coolant passage formed from the space to an exterior surface of the cylindrical valve, and a drive portion that is configured to rotate the cylindrical valve such that the coolant passage is connected to the supply line. 
         [0015]    The multi flow rate control valve may include a sealing member having a pipe shape for insertion of a front end portion of the supply line, wherein an end portion surface of the sealing member slidably contacts an exterior circumference of the cylindrical valve to form a sealing structure, and an elastic member that elastically pushes the sealing member toward the exterior circumference of the cylindrical valve. 
         [0016]    Coolant circulated an engine may be supplied to the multi flow rate control valve and the coolant may be supplied to the heater core, the EGR cooler, or the radiator depending on an operational state of the multi flow rate control valve. 
         [0017]    The pressure cap may include a cap housing that a lower portion thereof is connected to the supply line, a piston that is movably disposed in the cap housing, wherein movement of the piston depends on the pressure of the supply line, a pressure spring that elastically pushes the piston, a pressure valve that is disposed on the piston and is operated by the pressure of the supply line, the outlet that releases pressure or coolant supplied from the piston or the pressure valve, and a cap that is engaged with the outlet that is formed at an upper portion of the cap housing and supports the pressure spring. 
         [0018]    The supply line may include a first supply line that connects the multi flow rate control valve with the heater core so as to transfer the coolant, a second supply line that connects the multi flow rate control valve with the EGR cooler so as to transfer the coolant, and a third supply line that connects the multi flow rate control valve with the radiator so as to transfer the coolant. 
         [0019]    One side of the reservoir tank may be opened to an outside and the reservoir tank has a storage space for storing the coolant. The pressure cap is configured such that the pressure of the coolant line is less than a predetermined value that is higher than atmospheric pressure. 
         [0020]    In accordance with the present invention, a pressure cap is connected to coolant lines that are respectively supplied to a heater core, a radiator, and an EGR cooler such that the coolant is quickly supplemented and bubble that is included in the coolant can be quickly exhausted. 
         [0021]    Also, because a pressure cap release pressure to a reservoir tank depending on a pressure or a temperature condition around a multi flow rate control valve, damage of a multi flow rate control valve is prevented and overall coolant pressure and temperature can be quickly and accurately controlled. 
         [0022]    The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is an overall schematic diagram of an engine system having a multi flow rate control valve that is related to the present invention. 
           [0024]      FIG. 2  is an overall schematic diagram of an engine system having an exemplary multi flow rate control valve according to the present invention. 
           [0025]      FIG. 3  is a cross-sectional view of an exemplary multi flow rate control valve according to the present invention. 
           [0026]      FIG. 4  is a cross-sectional view of an exemplary pressure cap according to the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. 
         [0028]      FIG. 1  is an overall schematic diagram of an engine system having a multi flow rate control valve that is related to the present invention. Referring to  FIG. 1 , an engine system includes a cylinder block  150 , a cylinder head  155 , a multi flow rate control valve  110 , an EGR cooler  130 , an oil cooler  140 , a coolant pump  160 , a heater core  100 , a radiator  120 , a pressure cap  170 , and a reservoir tank  175 . 
         [0029]    Coolant that is pumped by the coolant pump  160  passes the cylinder block  150  and the cylinder head  155  to be supplied to the multi flow rate control valve  110 . The multi flow rate control valve  110  controls the coolant that is respectively supplied to the heater core  100 , the EGR cooler  130 , and the radiator  120 . The coolant passing the heater core  100 , the EGR cooler  130 , or the radiator  120  is supplied to the coolant pump  160  and circulates an engine system. 
         [0030]    A pressure cap  170  is disposed at one side of the radiator  120 , the pressure cap  170  functions as a cap and also performs releasing the pressure of coolant passing the radiator  120  to the reservoir tank  175 . A predetermined level of coolant is filled in the reservoir tank  175 , the coolant that is supplied to the radiator  120  through the pressure cap  170  is stored in the tank  175 . 
         [0031]      FIG. 2  is an overall schematic diagram of an engine system having a multi flow rate control valve according to various embodiments of the present invention. Referring to  FIG. 2 , an engine system includes a coolant pump  160 , a cylinder block  150 , a cylinder head  155 , a multi flow rate control valve  110 , a heater core  100 , an EGR cooler  130 , a radiator  120 , a pressure cap  170 , and a reservoir tank  175 , and includes a first diverging line  200 , a second diverging line  210 , a third diverging line  220 , and a connection line  230 . 
         [0032]    The first diverging line  200  is diverged from the first supply line  330  that is connected from the multi flow rate control valve  110  to the heater core  100 , the second diverging line  210  is diverged from the second supply line  335  that is connected from the multi flow rate control valve  110  to the EGR cooler  130 , and the third diverging line  220  is diverged from the third supply line  340  that is connected from the multi flow rate control valve  110  to the radiator  120 . 
         [0033]    The first diverging line  200 , the second diverging line  210 , and the third diverging line  220  join to one line and the joined line is connected to the pressure cap  170 . One side of the pressure cap  170  is connected to the reservoir tank  175  through the connection line  230 . 
         [0034]    In various embodiments of the present invention, the pressure cap  170  is respectively connected to the supply lines that are connected the heater core  100 , the radiator  120 , and the EGR cooler  130  through the first diverging line  200 , the second diverging line  210 , and the third diverging line  220  such that the coolant is quickly supplemented and the bubble that is included in the coolant is quickly exhausted. 
         [0035]    Depending on the temperature or the pressure around the multi flow rate control valve  110 , because the pressure cap  170  releases the pressure to the reservoir tank  175 , the damage of the multi flow rate control valve  110  is prevented, and overall coolant pressure and temperature can be quickly and accurately controlled. 
         [0036]    Generally, in case that the pressure cap  170  is disposed on a radiator, the pressure of the radiator  120  is relatively quickly controlled, but the pressure of the overall cooling system cannot be efficiently controlled. 
         [0037]      FIG. 3  is a cross-sectional view of a multi flow rate control valve according to various embodiments of the present invention. Referring to  FIG. 3 , a multi flow rate control valve  110  includes a motor housing  300 , an output gear  305 , a driven gear  310 , a rotation shaft  315 , a valve housing  302 , a cylindrical valve  320 , a sealing member  324 , and an elastic member  326 , and is respectively connected to a coolant inlet  325 , a third supply line  340 , a first supply line  330 , and a second supply line  335 . 
         [0038]    The coolant that is supplied from the cylinder head  155  through the coolant inlet  325  flows to a central portion of the cylindrical valve  320 . And, a coolant passage  321  is formed such that the coolant flows from the central portion to an exterior surface of the cylindrical valve  320 . The third supply line  340 , the first supply line  330 , and the second supply line  335  are disposed on the valve housing  302  corresponding to the coolant passage  321 . 
         [0039]    If the output gear  305  is rotated by a motor that is disposed inside the motor housing  300 , the driven gear  310  rotates, and if the rotation shaft  315  that is connected to the driven gear  310  rotates, the cylindrical valve  320  rotates. 
         [0040]    In accordance with the rotation of the cylindrical valve  320 , the coolant passage  321  corresponds to the third supply line  340 , the first supply line  330 , or the second supply line  335 , and the coolant is selectively supplied to the radiator  120 , the heater core  100 , or the EGR cooler  130 . 
         [0041]    A sealing member  324  and an elastic member  326  are disposed between the supply lines and an exterior circumference of the cylindrical valve  320  The sealing member  324  has a short pipe shape, one end of the supply line is inserted into the member  324 , a front end surface of the sealing member  324  contacts an exterior circumference of the cylindrical valve  320 , the elastic member  326  elastically pushes the sealing member  324  toward the cylindrical valve such that the sealing member  324  forms a sealing structure with the cylindrical valve  320 . 
         [0042]    Also, the pressure cap  170  is connected to the reservoir tank  175  through the connection line  230 , retrieves the coolant that overflows the pressure cap  170  to the reservoir tank  175 , and supplements lacking coolant from the reservoir tank  175  to the cooling system. 
         [0043]    The pressure cap  170  is respectively connected to a supply line that is connected to the radiator  12 , to a supply line that is connected to the heater core  100 , and a supply line that is connected to the EGR cooler  130  such that overall coolant pressure is quickly and efficiently controlled. Further, while the coolant is being supplemented through the pressure cap  170 , the coolant is quickly and efficiently supplemented. 
         [0044]      FIG. 4  is a cross-sectional view of a pressure cap according to various embodiments of the present invention. The pressure cap  170  includes a cap  400 , a pressure spring  410 , a cap housing  422 , a piston  424 , a pressure valve  420 , and an outlet  430 . A lower portion of the cap housing  422  is connected to the multi flow rate control valve  110 , and a side surface is connected to the reservoir tank  175  to form an outlet  430 . 
         [0045]    A piston  424  is disposed inside the cap housing  422 , and a pressure valve  420  that releases pressure or allows the coolant to pass is disposed in a middle or middle portion of the piston  424 . 
         [0046]    In a condition that the cap  400  is engaged with the cap housing  422 , the pressure spring  410  elastically pushes the piston  424  downwards to prevent the coolant from being exhausted through the outlet  430 , and while the pressure of the coolant is being increased, the piston  424  moves upwards, the pressure spring  410  is compressed. Further, when the coolant of the multi flow rate control valve  110  is lacking, the coolant can be supplied through the outlet  430  and the pressure valve  420 . 
         [0047]    For convenience in explanation and accurate definition in the appended claims, the terms “upper” or “lower”, “upward” or “downward”, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. 
         [0048]    The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.