Abstract:
A clutch oil reservoir cap according to an exemplary embodiment of the present invention including a head and a body may include an exhaust opening formed in the head for exhausting air, an intake hole formed in the head for inflow of air, and an operation valve disposed in the head, wherein the operation valve selectively opens or closes the exhaust opening and the intake hole according to fluctuation of pressure in a part below the operation valve.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2007-0082657, filed in the Korean Intellectual Property Office on Aug. 17, 2007, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     (a) Field of the Invention 
     The present invention relates to a clutch oil reservoir cap. More particularly, the present invention relates to a clutch oil reservoir cap that includes an operation valve and where pressure in the reservoir cap can be balanced with atmospheric pressure. 
     (b) Description of the Related Art 
     Generally, driving torque for a vehicle is generated by an engine and transmitted to the wheels through a shifting operation. 
     The shifting operation is for using power efficiently and a clutch is used in the shifting operation. 
     The clutch is operated by a hydraulic pump and a clutch oil reservoir is disposed for supplying oil to the hydraulic pump. 
     Pressure in the oil reservoir must be balanced with atmospheric pressure for supplying oil reliably. 
     Pressure in the oil reservoir can change according to temperature differences in summer and winter, or a volume change according to abrasion of a clutch disk can make a change of pressure in the oil reservoir. 
     It has been considered to make a hole for dealing with the pressure changes, however, the hole can become blocked by the clutch oil or the clutch oil can leak out through the hole. 
     The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention 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 OF THE INVENTION 
     Embodiments of the present invention has been made in an effort to provide a clutch oil reservoir cap that includes an exhaust opening, an intake hole, and an operation valve selectively opening or closing the exhaust opening and the intake hole for balancing pressure in the clutch oil reservoir cap and atmospheric pressure. 
     The clutch oil reservoir cap according to an exemplary embodiment of the present invention may prevent the exhaust opening and intake hole from becoming blocked or leaking oil. 
     The clutch oil reservoir cap according to an exemplary embodiment of the present invention may include a head and a body, comprising: an operation valve slidably mounted in the head and forming a first space and a second space therebetween; an intake hole formed in the head and the operation valve and selectively communicating the first space and the second space; and an exhaust opening formed in the head and exhausting air of the second space to the outside of the head; wherein the operation valve selectively opens or closes the exhaust opening and the intake hole according to a pressure difference between the first space and the second space in the body. An elastic member may be disposed in the head for supplying a restoring force to the operation valve, wherein an upper elastic member may disposed in the first space and a lower elastic member may disposed in the second space for supplying a restoring force to the operation valve respectively according to the pressure difference. 
     In an aspect, the first space may be formed between the head and upper surface of the operation valve and, the second space may be formed between the head and lower surface of the operation valve, and the intake hole includes: a first hole formed at a portion of the head and communicating the first space and an outside of the clutch oil reservoir cap; a second hole formed in a side of the head and connected to the first space; and a third hole formed in the operation valve and connected to the second space, wherein the second hole and the third hole are selectively communicated according to the pressure difference in the first space and the second space for balancing the pressure therebetween. The operation valve may include a first protrusion portion that is upwardly protruded in the operation valve and the third hole is formed therein. The exhaust opening may be formed at a junction of the head and the body. 
     In another aspect, the operation valve may include a second protrusion portion that is downwardly protruded in the operation valve and selectively closes or opens the exhaust opening according to the pressure difference in the first space and the second space. A blocking portion and a sealing rubber may be disposed in the body for preventing leakage of oil. The exhaust opening may be formed at a junction of the head and the body. The operation valve may include a second protrusion portion that is downwardly protruded in the operation valve and selectively closes or opens the exhaust opening according to the pressure difference in the first space and the second space. 
     In further another aspect, a third protrusion portion may be formed below the operation valve for supporting the elastic member and includes a guide hole thereof. The first space may be formed between the operation valve and the head, the second space is formed between the third protrusion portion and the operation valve, and the intake hole includes: a first hole formed at a portion of the head and communicating the first space and an outside of the clutch oil reservoir cap; a second hole formed in a side of the head and connected to the first space; and a third hole formed in the operation valve and connected to the second space, wherein the second hole and the third hole are selectively communicated according to the pressure difference in the first space and the second space for balancing the pressure therebetween. The operation valve may include a first protrusion portion that is upwardly protruded in the operation valve and the third hole is formed in the first protrusion portion. The exhaust opening may be formed at a junction of the head and the body, and a second protrusion portion is downwardly protruded in the operation valve and selectively closes or opens the exhaust opening through the guide hole according to pressure difference in the first space and the second space. 
     In another exemplary embodiment of the present invention, a clutch oil reservoir cap including a head and a body, may comprise: an operation valve slidably mounted in the head and forming a first space and a second space therebetween, wherein the second space is connected to an inside of the clutch oil reservoir tank; a first hole formed at a portion of the head and fluidly communicating the first space and an outside of the head; a second hole formed in the head and fluidly communicating with the first space; a third hole formed in the operation valve fluidly communicating with the second space; an exhaust opening selectively connected to the second space and exhausting air of the second space to the outside of the head; wherein the second hole and the third hole are disconnected and the exhaust opening is closed when pressure difference between the first space and the second space is substantially equal to zero; the second hole and the third hole is disconnected and the exhaust opening is open when pressure in the first space is lower than pressure in the second space; and the second hole and the third hole are connected, the exhaust opening is closed, and the first hole and the second hole are connected when pressure in the first space is equal to or higher than pressure in the second space. 
     An upper elastic member may be disposed in the first space and a lower elastic member may be disposed in the second space for supplying a restoring force to the operation valve respectively according to the pressure difference. The operation valve may include: a first protrusion portion that is upwardly protruded in the operation valve and the third hole is formed in the first protrusion portion; a second protrusion portion is downwardly protruded in the operation valve and selectively closes or opens the exhaust opening, wherein the exhaust opening is formed at a junction of the head and the body; and a third protrusion portion is formed at the body below the operation valve for supporting the lower elastic member and includes a guide hole thereof, wherein a portion of the second protrusion portion selectively moves through the guide hole to open or close the exhaust opening according to pressure difference in the first space and the second space. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic cross-sectional view showing a clutch oil reservoir cap according to an exemplary embodiment of the present invention. 
         FIG. 2  is a view showing an operation state of the clutch oil reservoir cap of  FIG. 1  when air is exhausted. 
         FIG. 3  is a view showing an operation state of the clutch oil reservoir cap of  FIG. 1  when air is flowed in. 
     
    
    
     REPRESENTATIVE REFERENCE NUMERALS 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 100: head 
                 110: first hole 
               
               
                   
                 120: second hole 
                 130: exhaust opening 
               
               
                   
                 140: first space 
                 200: body 
               
               
                   
                 210: sealing rubber 
                 220: blocking portion 
               
               
                   
                 230: connecting portion 
                 300: operation valve 
               
               
                   
                 310: first protrusion portion 
                 320: second protrusion portion 
               
               
                   
                 330: third hole 
                 340: second space 
               
               
                   
                 400: third protrusion portion 
                 410: upper elastic member 
               
               
                   
                 420: lower elastic member 
                 500: clutch oil reservoir tank 
               
               
                   
                   
               
             
          
         
       
     
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     An exemplary embodiment of the present invention will hereinafter be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a schematic cross-sectional view showing a clutch oil reservoir cap according to an exemplary embodiment of the present invention, and  FIG. 2  and  FIG. 3  are views showing operation states of the clutch oil reservoir cap of  FIG. 1  when air is exhausted and when air is flowed in, respectively. 
     A head  100  and a body  200  of a clutch oil reservoir cap  10  are shown in  FIG. 1  wherein the head  100  is integrally positioned above the body  200 . 
     An exhaust opening  130  is formed in a lower portion of the head  100  for selectively exhausting air. 
     An intake hole is formed in the head  100  for receiving air. 
     An operation valve  300  is slidably disposed in the head  100  for opening or closing the exhaust opening  130  and the intake hole. 
     A first space  140  is formed between the operation valve  300  and the upper portion of the head  100  and a second space  340  is formed between the operation valve  300  and the lower portion of the head  100 . 
     The intake hole includes a first hole  110  formed at upper portion of the head  100  for communicating the first space  140  and an outside of the clutch oil reservoir cap, a second hole  120  formed in a lateral side of the head  100  wherein the second hole  120  fluidly communicates with the first space, and a third hole  330  formed in a lateral side of the operation valve  300 . 
     The operation valve  300  includes a first protrusion portion  310  that is upwardly protruded in a lateral side of the operation valve  300  with a predetermined length and the third hole  330  is formed in the first protrusion portion  310  wherein the third hole  33  fluidly communicates with the second space  340 . 
     A second protrusion portion  320  is downwardly protruded from a lateral side of the operation valve  300  with a predetermined length. 
     A third protrusion portion  400  extends inwards from inner portion of the body  200 , and the second space  340  is formed between the operation valve  300  and the third protrusion portion  400 . A guide hole  405  is formed between the third protrusion portion  400  and the body  200  so that a lower portion of the second protrusion portion  320  is commutable therethrough as explained later. 
     In an exemplary embodiment of the present invention, the above-set forth exhaust opening  130  is formed at the guide hole  405  and extends outwardly as shown in  FIG. 1  so as to be selectively closed according to the movement of the operation valve  300 . 
     An upper elastic member  410  and a lower elastic member  420  are disposed in the first space  140  and the second space  340  respectively in the head  100  for supplying a restoring force to the operation valve  300 . 
     A connecting portion  230  for connecting the clutch oil reservoir cap  10  and a clutch oil reservoir tank  500  is formed in a lower portion of the body  200 , and a blocking portion  220  and a sealing rubber  210  are disposed in the body  200  for preventing leakage of oil. 
     Hereinafter, an operation of the clutch oil reservoir cap will be explained. 
       FIG. 1  is a view showing the clutch oil reservoir cap according to an exemplary embodiment of the present invention in which pressure is balanced with atmospheric pressure. 
     When a pressure in the oil reservoir tank is balanced with atmospheric pressure, the third hole  330  formed in the first protrusion portion  310  and the second hole  120  formed in the head  100  are not fluidly communicated. Also, the exhaust opening  130  is blocked by the second protrusion portion  320 . 
     Referring to  FIG. 2 , when pressure in the clutch oil reservoir tank is increased by increased temperature, or so on, the operation valve  300  moves upward in closing state of the second hole  120  and the third hole  330  by the restoring force of the lower elastic member  420  and the increased pressure in the clutch oil reservoir tank and the exhaust opening  130  is opened. When a pressure in the clutch oil tank is released through the exhaust opening  130 , the operation valve  300  moves downward by the restoring force of the upper elastic member  410  until the pressure in the clutch oil reservoir tank  500  and maintains a balanced state, as shown in  FIG. 1 . 
     When pressure in the clutch oil reservoir tank  500  is decreased by a decrease in temperature, or so on, the operation valve  300  slidably moves downward by the restoring force of the upper elastic member  410 , as shown in  FIG. 3 . Thus the second hole  120  and third hole  130  are communicated each other and air flows into the clutch oil reservoir tank but the exhaust opening  130  is closed by the second protrusion portion  320 . The air flows into the clutch oil reservoir tank via the first space  140  and the second space  340 . The pressure in the clutch oil tank  500  is not changed quickly due to the narrow holes of the second hole  120  and the third hole  330 , and thereby noise and vibration can be prevented. A contaminated material in the atmosphere can be blocked in the first space  140 . The second space  340  may prevent the clutch oil from flowing backward and leaking out. 
     When the pressure in the clutch oil reservoir tank  500  is balanced with the atmospheric pressure, the operation valve  300  moves upward by the restoring force of the lower elastic member  420  and maintains a balanced state, as shown in  FIG. 1 . 
     Elastic members may be both the upper elastic member  410  and the lower elastic member  420 , or in an exemplary embodiment, one of the upper elastic member  410  and the lower elastic member  420  may be disposed. 
     While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention 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.