Patent Publication Number: US-2007120081-A1

Title: Solenoid valve for different air discharging speeds

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to solenoid valves and more particularly, to such a solenoid valve that provides different air discharging speeds.  
      2. Description of the Related Art  
      Conventional solenoid valves for controlling discharging of an air commonly provide only one quick air discharging action, i.e., only rapid air discharging speed. However, there is still a demand for a slow air discharging speed. Therefore, solenoid valves that provide quick and slow air discharging speeds are developed.  
      However, conventional dual-speed solenoid valves or low-speed solenoid valves commonly have a complicated structure. These complicated solenoid valves may not work accurately during operation. Further, these complicated solenoid valves are difficult to install and, not durable in use.  
      Therefore, it is desirable to provide a solenoid valve that eliminates the aforesaid drawbacks.  
     SUMMARY OF THE INVENTION  
      The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a simple structure of solenoid valve, which provides a quick air discharging speed and a slow air discharging speed.  
      It is another object of the present invention to provide a simple structure of solenoid valve, which works accurately and positive.  
      It is still another object of the present invention to provide a simple structure of solenoid valve, which is easy to install and durable in use.  
      To achieve these and other objects of the present invention, the solenoid valve comprises a holder, the holder comprising a yoke frame, a receiving space defined in the yoke frame, a locating rod fixedly mounted in a side panel of the yoke frame, and an air discharging hole axially extending through two distal ends of the locating rod; a coil assembly, the coil assembly comprising a bobbin, the bobbin defining therein an axially extending sliding hole, and a coil wound round the bobbin; an actuating rod, the actuating rod comprising a rod body axially slidably mounted in the axially extending sliding hole of the bobbin; spring means stopped between the actuating rod and the locating rod; and seal means, the seal means comprising a flexible stopper adapted to seal the air discharging hole when the coil assembly is energized to move the actuating rod toward the locating rod; and a slow-speed air discharging hole for discharging of an air after blocking of the air discharging hole by the seal means. The slow-speed air discharging hole may be formed in the locating rod, the actuating rod, or the seal means. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is an exploded view of a solenoid valve according to the present invention.  
       FIG. 2  is a sectional side plain view of  FIG. 1 .  
       FIG. 3  is a sectional top assembly view taken of the solenoid valve shown in  FIG. 1 .  
       FIG. 4  is a sectional view taken along line  4 - 4  of  FIG. 3 .  
       FIG. 5  is similar to  FIG. 4  but showing the closed status of the solenoid valve.  
       FIG. 6  is a sectional assembly view of a part of an alternate form of the solenoid valve according to the present invention.  
       FIG. 7  is a sectional assembly view of a part of another alternate form of the solenoid valve according to the present invention.  
       FIG. 8  is a sectional assembly view of a part of still another alternate form of the solenoid valve according to the present invention.  
       FIG. 9  is a sectional assembly view of a part of still another alternate form of the solenoid valve according to the present invention.  
       FIG. 10  is a sectional assembly view of a part of still another alternate form of the solenoid valve according to the present invention.  
       FIG. 11  is a sectional assembly view of a part of still another alternate form of the solenoid valve according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring to FIGS.  1 ˜ 5 , a solenoid valve in accordance with one embodiment of the present invention is shown controllable to reciprocate. The solenoid valve comprises a holder  1 , a coil assembly  4 , an actuating rod  7 , a seal  90 , and a spring member S.  
      The holder  1  is comprised of a yoke frame  10 , a locating rod  20 , and a cover plate  30 . The yoke frame  10  is a metal frame having a bottom panel  11 , a top panel  13 , and a side panel  12  connected between the bottom panel  11  and the top panel  13  at one side. The bottom panel  11 , the top panel  13  and the side panel  12  surround a receiving space  15 . Further, the bottom panel  11  and the top panel  13  each have a protruding locating block  18 . The locating rod  20  is mounted in the side panel  12  of the yoke frame  10 , having a first rod section  21  disposed outside the yoke frame  11 , a second rod section  22  connected to one end of the first rod section  21 , a bearing portion  23  for supporting the spring member S, a stop edge  25  at one end of the bearing portion  23 , an axial through hole  27  axially extending through the two distal ends thereof, and an air discharging hole  29 , which is a groove transversely running over the stop edge  25 . The cover plate  30  has a body  31 , a center opening  32  cut through the center of the body  31 , and two mounting notches  33  disposed on two opposite lateral sides of the body  31  and respectively coupled to the locating blocks  18 .  
      The coil assembly  4  comprises a bobbin  40 , a coil  50 , and an electrically insulative film  60 . The bobbin  40  has a hollow cylindrical body  41  defining a sliding hole  45 . The coil  50  is formed of a copper wire  51  and wound round the hollow cylindrical body  41  of the bobbin  40 , having two lead-out ends  53 . The electrically insulative film  60  is wrapped about the coil  50 .  
      The actuating rod  7  is formed of a barrel-like shank  70 , which has a body  71  axially slidably mounted in the sliding hole  45  inside coil assembly  4 , a first mounting hole  73  axially backwardly extending to the rear side of the body  71 , a second mounting hole  74  formed in the front side of the body  71 , and bearing portion  75  provided around the periphery of the body  71  for bearing the spring member S. Further a magnet (not shown) is fixedly mounted in the first mounting hole  73  inside the actuating rod  7 .  
      The seal  90  is formed of a rubber stopper having a stopper body  91  fixedly fastened to the second mounting hole  74  of the actuating rod  7  and an annular protrusion  93  protruded from the front side of the stopper body  91  for stopping against the stop edge  25  of the locating rod  20 .  
      The spring member S is a compression spring supported between the bearing portion  23  of the locating rod  20  and the bearing portion  75  of the actuating rod  7 .  
      The operation of the solenoid valve is outlined hereinafter. Before connection of electric current to the coil  50 , as shown in  FIG. 4 , the actuating rod  7  does no work, and the spring member S pushes the actuating rod  7  away from the locating rod  20 , keeping the annular protrusion  93  of the seal  90  spaced from the stop edge  25  of the locating rod  20  at a distance for quick discharging of the air (not shown) through the axial through hole  27 .  
      On the contrary, as shown in  FIG. 5 , when the coil  50  is electrically energized to produce a magnetic force, the actuating rod  7  is forced by the magnetic force to overcome the spring force of the spring member S and to move toward the locating rod  20 , thereby stopping the annular protrusion  93  of the seal  90  against the stop edge  25  of the locating rod  20  over one end of the axial through hole  27 , for enabling the air to discharging through the air discharging hole  29 .  
       FIG. 6  shows an alternate form of the solenoid valve according to the present invention. According to this embodiment, the air discharging hole  29 A is a transverse inside hole perpendicularly extending from the axial through hole of the locating rod to the periphery of the locating rod.  
       FIG. 7  shows another alternate form of the solenoid valve according to the present invention. According to this embodiment, the seal  90 B is fixedly fastened to the actuating rod, having a transversely extending air discharging hole  99 B on the front side thereof.  
       FIG. 8  shows still another alternate form of the solenoid valve according to the present invention. According to this embodiment, the seal  90 C is fixedly fastened to the actuating rod, having an air discharging hole  99 C axially extending through the front and rear sides thereof.  
       FIG. 9  shows still another alternate form of the solenoid valve according to the present invention. According to this embodiment, the seal  90 D is fixedly mounted in the locating rod and partially protruding over the stop edge of the locating rod, having a through hole  95 D. Further, an air discharging groove  49 D is formed on the front side of the body of the actuating rod. The air discharging groove  49 D is disposed in communication with the through hole  95 D when the actuating rod is stopped against the locating rod.  
       FIG. 10  shows still another alternate form of the solenoid valve according to the present invention. According to this embodiment, the seal  90 D is same as the embodiment shown in  FIG. 9 ; an air discharging screw tip  47 E is threaded into the second mounting hole of the actuating rod, having an air discharging hole  99 F axially extending through the front and rear sides thereof for discharging of the air at a low speed.  
       FIG. 11  shows still another alternate form of the solenoid valve according to the present invention. According to this embodiment, the seal  90 F is threaded into the second mounting hole of the actuating rod, having an air discharging groove  471 E transversely formed on the front side thereof for discharging of the air at a low speed.  
      As indicated above, the invention provides a solenoid valve, which has the benefits as follows:  
      1. The solenoid valve has a simple structure that provides a quick air discharging speed and a slow air discharging speed.  
      2. The solenoid valve is easy to install and durable in use, and works accurately and positively.