Abstract:
A thermostat having improved reactivity may include a thermostat case having side connected to first and second passages, and a third passage formed between the first and second passages in a side direction, a valve body where first and second valves are formed to open/close the first and second passages, and a mounting space is formed in the valve body, an elastic member elastically pushing the valve body in a direction of the first valve such that the first valve closes the first passage, and a drive portion moving the valve body in response to contraction or expansion of a wax disposed in the mounting space. A flowing turn wall may be formed to correspond to the third passage such that a liquid flowing in through the second passage moves in a direction opposite to the third passage.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority of Korean Patent Application Number 10-2012-0114984 filed Oct. 16, 2012, 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 a thermostat that the reactivity thereof is improved and changes a passage of a coolant depending on the temperature of the coolant and actively controls the coolant temperature to prevent the overheating thereof. 
         [0004]    2. Description of Related Art 
         [0005]    A thermostat for a vehicle is disposed between an engine and a radiator and is opened/closed in response to the temperature variation of coolant to adjust the flow rate of the coolant, and therefore the temperature of the coolant is controlled in a predetermined range. 
         [0006]    A mechanical thermostat expands wax depending on the temperature of the coolant, and the expanding force of the wax makes a piston move the valve of the thermostat. 
         [0007]    The mechanical thermostat is operated in response to a predetermined opening/closing temperature of the coolant to open/close the valve only in a predetermined temperature condition, and therefore the mechanical thermostat does not actively move against changes of the driving circumstances of the vehicle. 
         [0008]    Accordingly, an electrical thermostat has been introduced to complements the drawback of the mechanical thermostat, and the electrical thermostat is operated to sustain the coolant temperature in an optimized range. 
         [0009]    The electrical thermostat actively controls the coolant temperature of the engine according to the driving circumstances such as the load level of the vehicle to sustain the optimized coolant temperature, and the electrical thermostat can improve fuel consumption efficiency and reduce exhaust gas. 
         [0010]    Meanwhile, when a first valve is closed in a thermostat, the coolant that is supplied through a second passage flows around a wax case that is disposed in a valve guide and wax that is charged in the wax case is contracted or expanded. 
         [0011]    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 
       [0012]    The present invention has been made in an effort to provide a thermostat that the reactivity thereof is improved having advantages of improving the reactivity of the wax in response to the coolant temperature and improving the efficiency of an engine. Further, the present invention provides a thermostat having advantages of preventing the relative rotation of the drive portion for operating a piston and a valve body. 
         [0013]    A thermostat having improved reactivity according to various aspects of the present invention may include a thermostat case that one side thereof is connected to a first passage, the other side thereof is connected to a second passage, and a third passage is formed between the first and second passages in a side direction, a valve body where a first valve is formed at one side thereof to open/close the first passage, a second valve is formed at the other side thereof to open/close the second passage, and a mounting space is formed therein, an elastic member that elastically pushes the valve body in a direction of the first valve such that the first valve closes the first passage, and a drive portion that moves the valve body in response to contraction or expansion of a wax that is disposed in the mounting space of the valve body, wherein a flowing turn wall is formed to correspond to the third passage such that a liquid that flows in through the second passage moves in a direction opposite to the third passage. 
         [0014]    The valve body may include a length-direction element that is extended in a length direction and is arranged along a circumference of the drive portion at a first predetermined distance, and a circumference-direction element that is extended along the circumference of the drive portion and is arranged in a length direction at a second predetermined distance, wherein the flowing turn wall is formed in a section formed by the circumference-direction element and the length-direction element. 
         [0015]    The flowing turn wall may be formed at an end portion of the valve body. The flowing turn wall may be integrally formed with the circumference-direction element or the length-direction element or with both the circumference-direction element and the length-direction element. 
         [0016]    The circumference-direction element may include a first ring member that is formed at a central portion of the valve body, and a second ring member that is formed at one end portion of the valve body, wherein the flowing turn wall is formed between the first and second ring members. 
         [0017]    The drive portion may include the drive portion includes a main piston that is movable in response to the contraction or expansion of the wax, a piston support portion supporting one end portion of the piston is formed in the mounting space of the valve body, and the second valve is integrally formed along a circumference of the piston support portion. 
         [0018]    A mounting hole that is connected to the mounting space may be formed at a central portion of the first valve, a groove may be formed on the interior circumference of the mounting hole in the length direction, and a protrusion may be formed on the exterior circumference of the drive portion that is inserted into the mounting hole to correspond to the groove. 
         [0019]    In a thermostat that the reactivity thereof is improved according to various aspects of the present invention, the flowing turn wall that is formed on the valve body helps the coolant to pass the wax case such that the reactivity for the coolant temperature is improved. 
         [0020]    Further, the valve body is formed to be integrally with the first valve, a groove is formed on the interior circumference of a mounting hole of a first valve, a protrusion is formed on the exterior circumference of the drive portion that is inserted into a mounting space of the valve body through a mounting hole such that the movement of the valve body is guided in a length direction and the relative rotation of the valve guide and the first valve is prevented. 
         [0021]    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 
         [0022]      FIG. 1  is a partial cross sectional view of an exemplary thermostat that is disposed on an engine according to the present invention. 
           [0023]      FIG. 2  is a side view showing a case that a drive portion is inserted into a valve body in an exemplary thermostat according to the present invention. 
           [0024]      FIG. 3  is a perspective view of a valve body that a first valve and a second valve are integrally formed in an exemplary thermostat according to the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0025]    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. 
         [0026]      FIG. 1  is a partial cross sectional view of a thermostat that is disposed on an engine according to various embodiments of the present invention. Referring to  FIG. 1 , an engine having a thermostat includes a radiator  150 , a coolant outlet  160  of an engine, a coolant inlet  170  of an engine, and a thermostat  100 . 
         [0027]    The thermostat  100  includes a thermostat case  137 , and a first passage  155  is formed to be connected to the radiator  150 , a second passage  165  is formed to be connected to the coolant outlet  160 , and a third passage  175  is connected to the coolant inlet  170  in the thermostat case  137 . 
         [0028]    A coolant pump in various embodiments of the present invention is disposed between the third passage  175  and the coolant inlet  170  to circulate coolant from the thermostat  100  to the engine. 
         [0029]    As shown in drawings, the first passage  155  is formed at an upper side in an upward direction, the second passage  165  is formed at a lower side in a downward direction, and the third passage  175  is formed between the first and second passage  155  and  165  at a side (e.g., left side) in a lateral direction. 
         [0030]    A joining space  139  is formed in the thermostat case  137  to be connected to the first passage  155 , the second passage  165 , and the third passage  175 , and the valve body  125  is disposed in the joining space  139 . 
         [0031]    A first valve  200  is integrally formed at an upper end portion of the valve body  125  to selectively close the first passage  155 , and a second valve  205  is integrally formed at a lower end portion of the valve body  125  to selectively close the second passage  165 . One will appreciate that these integral components may be monolithically formed. 
         [0032]    Further, a valve O-ring  130  is mounted along an exterior circumference of the first valve  200  to contact the interior circumference of the first passage  155 . 
         [0033]    A main spring  145  is disposed inside the thermostat case  137 , and an upper end portion of the main spring  145  elastically supports the lower end portion of the first valve  200  in an upward direction and a lower end portion of the main spring  145  is supported by an inner side of the thermostat case  137 . The mainspring  145  has a coil spring structure and the valve body  125  is inserted into the main spring  145 . 
         [0034]    Further, a mounting space is formed along a central portion of the valve body  125  from an upper end side to a lower end side, and a drive portion that moves the valve body  125  is inserted into the mounting space  215 . 
         [0035]    The drive portion includes a main piston  120 , a rubber piston  148 , a piston guide  127 , a semi fluid  147 , a diaphragm  115 , a wax  110 , a wax case  135 , and a glow plug  105 , wherein the glow plug  105  is electrically connected to a connector  140 . 
         [0036]    And, a piston support portion  225  is formed at a central portion of the second valve  205  that is formed at a lower side of the valve body  125 . Further, the second valve  205  is integrally formed with the piston support portion  225 . One will appreciate that these integral components may be monolithically formed. 
         [0037]    A flowing turn wall  122  is formed on the valve body  125  in various embodiments of the present invention. The flowing turn wall  122  is formed at the same side where the third passage  175  is disposed and at a lower end portion of the valve body  125 . 
         [0038]    Here, if the second valve  205  opens the second passage  165 , the coolant flows upward through the second passage  165 , wherein the coolant flows to the right side by the flowing turn wall  122  that is formed at a left side. 
         [0039]    More particularly, the coolant flows in a right side of the valve body  125  through the second passage  165 , and then the coolant of the right side penetrates the valve body  125  is supplied to the third passage  175  of the left side. While the coolant penetrates the valve body  125 , the coolant flows around the wax case  135 , and the wax  110  that is charged in the wax case  135  is contracted or expanded by the temperature of the coolant in various embodiments of the present invention. 
         [0040]    If there were no flowing turn wall  122 , almost all the coolant would not pass the wax case  135 , instead it would pass the third passage  175 , and therefore the temperature reactivity of the wax  110  would be deteriorated. 
         [0041]      FIG. 2  is a side view showing a case that a drive portion is inserted into a valve body in a thermostat according to various embodiments of the present invention, and FIG.  3  is a perspective view of a valve body that a first valve and a second valve are integrally formed in a thermostat according to various embodiments of the present invention. One will appreciate that these integral components may be monolithically formed. 
         [0042]    Referring to  FIG. 2  and  FIG. 3 , the first valve  200  is formed at an upper end portion of the valve body  125 , a valve O-ring  130  is disposed along a groove that is formed along the circumference direction of the first valve  200 . 
         [0043]    A mounting space  215  is formed at a central portion of the valve body  125  along the length direction of the valve body  125 , and one end part of the drive portion is inserted into the mounting space  215 . As shown in the drawings, the drive portion includes the wax case  135 , a piston guide  127 , and a main piston  120 . 
         [0044]    The valve body  125  includes a length-direction element  210  and a circumference-direction element  218 . The length-direction element  210  is extended in a length direction of the valve body  125  and is arranged along the circumference direction of the mounting space  215  at a predetermined gap. And, the circumference-direction element  218  is extended along the circumference of the mounting space  215  and is arranged along the length direction of the valve body  125  at a predetermined distance. 
         [0045]    The circumference-direction element  218  includes a first ring member  217  and a second ring member  220 . The first ring member  217  is formed at a central portion of the length direction of the valve body  125  and the second ring member  220  is formed at a lower end portion of the valve body  125 . 
         [0046]    The second valve  205  is disposed between the first and second ring member  217  and  220 , and the piston support portion  225  corresponding to the second valve  205  is formed in the mounting space  215 . 
         [0047]    The flowing turn wall  122  is formed to correspond to the third passage  175  between the first ring member  217  and the second ring member  220 . The flowing turn wall  122  is only formed in a predetermined range along the circumference of the valve body  125 . 
         [0048]    Three length-direction elements  210  can be formed with approximately 120 degrees in a circumferential direction of the valve body, and the flowing turn wall  122  can be formed in approximately 120 degrees range in a circumference direction of the valve body  125  in various embodiments of the present invention. 
         [0049]    Referring to  FIG. 3 , a mounting hole  300  is formed at a central portion of an upper end surface of the first valve  200  and the valve body  125  corresponding to the mounting hole  300  is integrally formed with the first valve  200  in a lower direction. One will appreciate that these integral components may be monolithically formed. 
         [0050]    The mounting space  215  is formed at a central portion of the valve body  125  in a length direction thereof, and the drive portion is inserted into the mounting space  215  through the mounting hole  300 . 
         [0051]    A groove  310  is formed on the interior circumference of the mounting hole  300  to guide the movement of the drive portion and the first valve  200  and to prevent the relative rotation thereof. 
         [0052]    Referring to  FIG. 2  and  FIG. 3 , a protrusion corresponding to the groove  310  is formed on the exterior circumference of the wax case  135  of the drive portion in the length direction. Accordingly, when the drive portion pushes the first valve  200  and the valve body  125 , the drive portion guides the movement of the first valve  200  and the valve body  125  along the groove and the protrusion. 
         [0053]    And, the engagement structure of the protrusion and the groove  310  that is formed on the interior circumference of the mounting hole  300  can prevent the relative rotation between the wax case  135  and the first valve  200  (and  125 ). 
         [0054]    The length (or height) of the flowing turn wall  122  can be readily varied according to the position of the third passage and the design specification in various embodiments of the present invention. 
         [0055]    For convenience in explanation and accurate definition in the appended claims, the terms “upper” or “lower”, “left” or “right”, “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. 
         [0056]    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.