Abstract:
A gas valve having a valve body that at least partially defines a gas enclosure. The valve body has an intake, an outlet and a hole for communicating the outlet with the intake. A valve seat within the gas enclosure cooperates with the hole to permit or to prevent the passage of gas through the hole. An electrically activated actuator, when activated, is configured to move or keep the valve seat in the open position. The gas valve includes connection means that connect the actuator to the outside of the gas valve, the connection means being disposed at least in part on a metal core printed circuit board. The printed circuit board is soldered to a metal structure located within the gas enclosure to at least partially seal the gas enclosure, the metal structure supporting, at least in part, the electrical actuator.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a US national phase filing of International Application No. PCT/EP2013/053912, filed Feb. 27, 2013, which relates to and claims the benefit of and priority to European Application No. EP12382069, filed Feb. 28, 2012. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to gas valves that need an external power supply, and to assembly methods for gas valves. 
       BACKGROUND 
       [0003]    The use of gas valves to control the passage of gas that reaches a burner (or another device of this type) is widely known. With a gas valve the passage of gas may be allowed or prevented: to prevent it the gas valve is closed completely, and to allow it the gas valve is opened. These type of valves are known as ON/OFF-type valves, although other types of gas valves are known, namely regulation valves, which may regulate the flow of gas when its passage is permitted, so that the passage of gas may be opened to a greater or lesser extent, enabling the passage of a larger or smaller flow of gas as required. 
         [0004]    The valves comprise a gas intake through which they receive the gas originating from a gas source, for example, a gas outlet through which the flow of gas exits in a regulated manner towards the required destination, such as a burner, a through hole that connects the intake to the outlet, and a valve seat or head that cooperates with the through hole when it is actuated to allow and prevent the passage of gas. 
         [0005]    The valve seat may be actuated in a mechanical or electrical manner. When it is actuated in a mechanical manner a force is exerted on it in order to move it to the corresponding position, and on many occasions, an electrical unit, generally magnetic, is required to then keep it in said position, which requires an electrical supply in order to keep acting on the valve seat. 
         [0006]    When it is actuated in an electrical manner it is activated by an electrical unit, generally magnetic, which requires an electrical supply in order to keep acting on the valve seat. Similarly, in order to keep it in the required position, an additional electrical or magnetic unit may be used as the power requirements are inferior to those required to move the valve seat, in which case the electrical or magnetic unit also requires an electrical supply. 
         [0007]    Generally the supply to the electrical or magnetic units comes from outside the valve, both when the valve seat is actuated in a mechanical manner and when it is actuated in an electrical manner. Said valve must thus comprise an outward connection through which the electrical or magnetic units may be supplied from the outside, while the sealed nature of the inside of the valve must also be maintained. 
         [0008]    EP1640664A2 discloses a control valve assembly including an inlet for receiving a gas flow and an outlet for providing the gas flow to a gas burner. The assembly also includes a positive-shutoff valve for interrupting the gas flow from the inlet. A micro electromechanical system valve (MEMS) is coupled in series to the positive-shutoff valve between the inlet and the outlet for regulating the gas flow from the inlet to the outlet. 
         [0009]    WO98/57081A1 discloses a miniaturized magnetic valve suitable for integration into an electric or electronic circuit by mounting on a printed circuit board. 
         [0010]    WO2008/034525A1 discloses a valve control unit for a pressure modulator of a commercial vehicle. The unit comprises solenoid valves provided with solenoids which are fixed to a printed circuit board. 
         [0011]    Document EP1382907A1 discloses a valve that comprises an electrical or magnetic unit and connections that extend outwards to supply the electrical or magnetic unit. 
       SUMMARY OF THE DISCLOSURE 
       [0012]    The gas valve comprises a gas enclosure with an intake, an outlet and a through hole to communicate the outlet with the intake, and a valve member that comprises a valve seat that cooperates with the through hole to allow or prevent the passage of gas through the through hole. The valve also comprises actuation means that acts on the valve member at least in order to keep the valve seat in a required position, and connection means to supply the actuation means from the outside of the valve. 
         [0013]    The valve also comprises a metal core printed circuit board to which the valve member is soldered and which comprises, at least partially, the connection means. The valve member comprises a metal structure that is formed by a material that can be soldered, which is fixed to the printed circuit board, which defines an inner housing where the actuation means are disposed, and which comprises at least one window through which the connection means are connected to the actuation means. 
         [0014]    The valve can thus be electrically supplied from the outside in a simple and easy manner, a sealed closure of the valve also being provided. As a result, the valve can be supplied with power from the outside while maintaining the necessary sealing integrity in the gas enclosure in a simple manner, as it is the printed circuit board itself which provides the sealing integrity. Furthermore, as the structure is soldered to the printed circuit board, the valve can be assembled in a simple manner with automated soldering processes, for example. 
         [0015]    It is another object of the invention to provide an assembly method for a gas valve comprising a valve member with a valve seat to prevent or allow the passage of gas through it, and actuation means that are adapted to keep the valve seat in an open position in which the passage of gas is allowed and which are supplied from the outside of the valve, as described in the claims. 
         [0016]    In the method the actuation means are housed in the valve member, the valve member is disposed with the actuation means on a metal core printed circuit board, and the valve member is soldered to the printed circuit board. As a result, the gas valve can be assembled in a simple manner. 
         [0017]    These and other advantages and characteristics will be made evident in the light of the drawings and the detailed description thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a perspective view of a valve according to one embodiment. 
           [0019]      FIG. 2  is a cross-sectional view of the valve of  FIG. 1 , with a through hole of the valve closed. 
           [0020]      FIG. 3  is a cross-sectional view of the valve of  FIG. 1 , with the through hole of the valve open. 
           [0021]      FIG. 4  shows actuation means of the valve of  FIG. 1 . 
           [0022]      FIG. 5  shows a structure of a valve member of the valve of  FIG. 1 , disposed on a printed circuit board of the valve. 
           [0023]      FIG. 6  shows a cross-sectional of an intermediate part of the actuation means of the valve of  FIG. 1  according to one embodiment. 
           [0024]      FIG. 7  shows a cross-section of the printed circuit board of the valve of  FIG. 1 . 
           [0025]      FIG. 8  shows a cross-sectional view of a valve seat of the valve of  FIG. 1  according to one embodiment. 
           [0026]      FIG. 9  shows a cross-sectional view of a first part of the valve seat of  FIG. 8 . 
           [0027]      FIG. 10  shows a cross-sectional view of a second part of the valve seat of  FIG. 8 . 
           [0028]      FIG. 11  shows a cross-sectional view of a third part of the valve seat of  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    A first aspect relates to a gas valve  300 , which is of the ON/OFF type.  FIGS. 1 and 2  show an embodiment of the valve  300 , which comprises a gas enclosure  1  with an intake  10  for the gas, an outlet  11  for said gas, and a through hole  13  to communicate the outlet  11  with the intake  10 . The valve  300  also comprises a valve member, preferably in the gas enclosure  1 , comprising a valve seat or head  30  that cooperates with the through hole  13  to prevent or allow the flow of gas that reaches the outlet  11 . The valve seat  30  can thus comprise two positions: a closed position shown in  FIG. 2 , in which it does not allow the passage of gas through the through hole  13 , and an open position shown in  FIG. 3 , in which it allows the passage of a certain flow of gas through the through hole  13 . 
         [0030]    The valve  300  comprises a valve body  100  that comprises the gas enclosure  1 , the intake  10  and the outlet  11 , and the valve member and the actuation means are disposed in the gas enclosure  1 . Preferably the gas enclosure  1  comprises a chamber  109  where the valve member and, at least partially, the actuation means are disposed, an intake pipe  110  that communicates the intake  10  with the chamber  109 , and an outlet pipe  111  that communicates the chamber  109  with the outlet  11 , the through hole  13  being possible to be corresponded with the start of the outlet pipe  111 . 
         [0031]    The valve  300  comprises actuation means that acts on the valve member at least in order to keep the valve seat  30  in the required position, and connection means to supply the actuation means from the outside of the valve  300 . In a rest situation, where the valve  300  is not operating with no power being supplied to the valve, the through hole  13  is closed to prevent the passage of gas through it for safety reasons, so that the required position corresponds in this case with the open position. To provide the closure the valve  300  comprises closure means, preferably a spring  4 , which will be described later and which exert a pressure on the valve seat  30  towards the through hole  13 . 
         [0032]    The valve  300  comprises a metal printed circuit board  6 , also know in the art as a metal core printed circuit board (MCPCB), to which the valve member is fixed and which comprises, at least partially, the connection means, and the valve member comprises a metal structure  31  that is fixed to the printed circuit board  6  preferably by means of soldering, which defines an inner housing where the actuation means is disposed at least partially, and which comprises at least one window  33  through which the connection means are connected to the actuation means. The material of the structure  31 , in the case of being soldered to the printed circuit board  6 , corresponds with a solderable material, such as nickel-plated steel, and the printed circuit board  6  comprises, at least in the areas to be soldered with structure  31 , a material which is solderable such as tin (normally in the form of a track or pad). 
         [0033]    As a result, the actuation means can be supplied from the outside in a simple manner, the necessary sealing integrity in the gas enclosure  1  being maintained, as the printed circuit board  6  itself provides the sealing integrity. Furthermore, as the structure  31  is soldered to the printed circuit board  6 , the valve  300  can be assembled in a simple manner with automated soldering processes for example. The valve body  100  can comprise a housing to house a seal  101  or an equivalent member to provide a sealed closure between the printed circuit board  6  and the valve body  100 . In this case, in order to close the through hole  13 , the valve member  30  cooperates with the valve body  100  as shown in  FIG. 2 . 
         [0034]    With reference to  FIG. 4 , the actuation means comprise a magnetic core  23  disposed in the inner housing that defines the structure  31 , preferably a steel frame, at least one coil  24  disposed in said inner housing, a first terminal  26  that is fixed to one end of the coil  24  and which passes through the window  33 , and a second terminal  27  that is fixed to the opposite end of the coil  24  which passes through the window  33 , so that the supply reaches the coil  24  through the terminals  26  and  27 , the actuation means thus being supplied. When the valve  300  is supplied, due to the current that passes through the coil  24  a magnetic field is generated that produces an opposing force to the spring  4 , and when said force is greater than the force generated by the spring  4  the valve seat  30  is attracted from the closed position to the open position, the passage of gas being opened through the through hole  13 . The current necessary to keep the passage of gas open is smaller than the current necessary to open it, as a result of which, in one embodiment the valve  300  may comprise two coils, one to open the passage and another to keep it open. In another embodiment the passage of gas may be opened mechanically, so that the coil is only in charge of keeping the passage open. The valve seat  30  is disposed on the structure  31 , which enables it to be attracted by the force produced by the magnetic field and/or kept in the open position. 
         [0035]    The connection means comprise at least one conduction path  66  and  67  on the printed circuit board  6  for each terminal  26  and  27 , as shown by way of example in  FIG. 5 . Each terminal  26  and  27  is fixed by means of soldering to the corresponding conduction path  66  and  67  on the outside of the structure  31 . The printed circuit board  6  comprises a connection zone  60  that is adapted to support a connection with a connector or an equivalent member for example, through which the valve is connected to an external supply source. The conduction paths  66  and  67  extend from the connection zone  60  to at least the point of connection with the terminals  26  and  27 , so that the supply reaches the terminals  26  and  27  originating from an external supply source by means of the connection zone  60  and the conduction paths  66  and  67 , the coil  24  and therefore the actuation means thereby being supplied. The structure  31  preferably comprises a window  33  for each terminal  26  and  27 , one window  33  being disposed at 180° in relation to the other window  33 . In addition, preferably, each window  33  extends along the entire axial length of the structure  31 , as shown in  FIG. 5 . 
         [0036]    The structure  31  comprises a substantially cylindrical shape and the actuation means comprise a intermediate ring-shaped part  22  shown in  FIG. 6 , which is disposed in the inner housing of the structure  31 , which comprises a central through hole  22   a  that is passed through at least partially by the core  23 , and which comprises a substantially “C” shape defining a ring-shaped housing  22   b  along with the structure  31  where the coil  24  wound in relation to the central hole  22   a  is disposed. The inner housing is thus delimited by the structure  31  itself, the printed circuit board  6  and the valve seat  30  when it is in the open position. The material of the intermediate part  22  is a material that does not conduct electricity, such as a type of elastomer, for example, although it preferably corresponds with a high heat-resistant plastic, which also withstands high temperatures such as those generated in a soldering process for example. As a result, although the valve  300  is introduced into a soldering oven for example so that the requisite solderings may be carried out, the intermediate part does not deform or melt, for example. 
         [0037]    The intermediate part  22  preferably comprises a ring-shaped extension  22   c  that covers and holds the part of the terminals  26  and  27  that is disposed in the inner housing of the structure  31 , although it can also comprise an extension  22   c  for each terminal  26  and  27 . The extension  22   c  (or the extensions  22   c,  as the case may be) are disposed between the ring-shaped housing  22   b  of the intermediate part  22  and the printed circuit board  6 , and, as shown by way of example in  FIG. 7 , the printed circuit board  6  comprises a first zone  61  where the terminals  26  and  27  are soldered, and a second zone  62  where the structure  31  of the valve member is soldered, the second zone  62  corresponding with a depression of the printed circuit board  6 . According to one embodiment, the terminals  26  and  27  extend substantially parallel to the printed circuit board  6 , and due to the extension  22   c  (or extensions  22   c ), if there were no depression in the printed circuit board  6 , the terminals  26  and  27  would become distanced from the soldering surface of the printed circuit board  6  and an additional action would be necessary in order to bring them closer or do what is required to enable the soldering. Thanks to the depression the terminals  26  and  27  remain in contact or very close to the soldering surface of the printed circuit board  6 , preventing the need for additional actions for correct soldering, resulting in a simplification of the assembly or fitting process of the valve and a reduction in the cost of said assembly or fitting. The second zone  62  preferably comprises a substantially circular shape, with a depth that allows the correct soldering of the terminals  26  and  27  without having to perform additional actions, as commented. 
         [0038]    The intermediate part  22  also comprises a channel, not shown in the Figures, on the part of the extension  22   c  that covers a terminal  26 , in order to guide the end of the coil  24  that is connected to the corresponding terminal  26  towards the inner housing of the structure  31  from said terminal  26 , and a groove  22 e on the part of the extension  22   c  that covers the other terminal  27 , in order to guide the end of the coil  24  that is connected to said terminal  27  towards said terminal  27  from the inner housing of the structure  31 . 
         [0039]    As commented above, the closure means preferably comprises a spring  4 . The spring  4  is coiled on the valve seat  30  and on the structure  31 , and in the absence of supply of the actuation means, the force it exerts causes the valve seating  30  to become separated from the actuation means and close the through hole  13 , preventing the passage of gas through it. As a result, this situation corresponds with a rest position of the spring  4 . When, due to the supply, the force generated by the actuation means exceeds that of the spring  4 , the spring  4  is compressed and as a result the valve seat  30  moves closer to the actuation means opening the through hole  13 , thereby allowing the passage of gas through it. As a result, this situation corresponds with a position of compression of the spring  4 . With the spring  4  in the compression position, if the supply to the actuation means is stopped they stop generating the force that keeps the spring  4  in that position, and the spring  4  returns to its rest position. 
         [0040]    The structure  31  may comprise a ring-shaped projection  31   a,  on which at least part of a turn of the spring  4  is supported. The projection  31   a  divides the structure  31  into a first zone  31   b  with a diameter substantially equal to the diameter of the valve seat  30  and a second zone  31   c  with a smaller diameter, the second zone  31   c  being between the first zone  31   b  and the valve seat  30 . Thanks to this division, and in particular to the projection  31   a,  when the spring  4  changes position its turns are prevented from being disposed between the valve seat  30  and the actuation means, which may result in, for example, the valve  300  not operating correctly, the blocking of the valve  300 , or even the breakage of the valve  300 . 
         [0041]    With reference to  FIG. 8 , where an embodiment of the valve seat  30  is shown, the valve seat  30  can comprise at least three different members, that are joined and move as a single body in the direction of closing the through hole  13  or in the direction of opening it: a first part  301  of a ferromagnetic material, a second part  302  of an elastomer material such as silicon, viton, NBR or HNBR, for example, and a third part  303  that preferably corresponds with a steel spring washer. 
         [0042]    When the coil  24  is supplied with a current, a magnetic field is generated that has as its function the generating of a force to attract the valve seating  30  towards it or to keep it in said attracted position (open position). To enable the attraction or the maintaining of it, the valve seat  30  comprises a ferromagnetic material that, due to electromagnetism properties, is attracted by the force generated by the magnetic field. As a result, in this embodiment the part of the valve seat  30  on which the attraction force is exerted is the first part  301 , and as the second part  302  and the third part  303  are joined to the first part  301 , said parts  302  and  303  are also attracted, thereby the valve seat  30  being attracted. As a result, the passage of gas through the through hole  13  is opened. 
         [0043]    When the valve seat  30  is in the closed position, in the embodiment of the valve seat  30  illustrated in the figures the part in charge of closing the through hole  13  is the second part  302 , which presses against a surface  102  of the valve body  100  that surrounds the through hole  13 . The valve body  100  is preferably metallic, so that the second part  302  is made of elastomer material in order to cause a sealed closure of the through hole  13  and prevent in a safe manner the passage of gas through it. 
         [0044]    In the embodiment of the valve seat  30  illustrated in the figures, the main function of the third part  303  of the valve seat  30  is to keep the second part  302  joined to the first part  301 , and to thereby prevent, when the first part  301  is attracted or maintained in its position by the force generated by the magnetic field, the second part  302  to be released from the first part  301 , which would result in the through hole  13  not being opened or not being opened in the required manner, or even in the event that it was open, it could happen that it is not closed correctly when required. 
         [0045]    Preferably, in the embodiment of the valve seating  30  illustrated in the figures the valve seat  30  comprises a circular or cylindrical shape. The three parts  301 ,  302  and  303  which make up the valve seat would thus have the same shape. The first part  301  comprises a central column  311  and a circular outer column  312  that extends along its perimeter, a ring-shaped housing  313  being defined between the columns  311  and  312 . Thus, in a cross-section such as the one shown in  FIG. 9  for example, the first part  301  comprises a substantially inverted “M” shape. In other embodiments it may not include the outer column  312 . 
         [0046]    The second part  302 , shown by way of example in  FIG. 10 , is disposed in the ring-shaped housing  313  defined between the columns  311  and  312  of the first part  301 , and comprises a central hole that is passed through by the central column  311  of the first part  301 . The first part  301  can comprise a first groove in the outer surface of the central column  311  to house one end of the second part  302 , both parts  301  and  302  thus being joined to each other, although the diameter D 1  of the central column  311  of the first part  301  is preferably greater than the diameter D 2  of the central hole of the second part  302 , so that the second part  302  withstands stretching when it is disposed in the ring-shaped housing  313 , it thus being connected to the first part  301  while guaranteeing sealing integrity in the closure between the first part  301  and the second part  302 . Preferably the diameter D 2  of the central hole of the second part  302  is between approximately 10% and approximately 20% smaller than the diameter D 1  of the central column  311  of the first part  301 . For example, the diameter D 2  may be 16% smaller than the diameter D 1 , the diameter D 1  being equal to 4.2 millimetres and the diameter D 1  equal to 5 millimetres. In addition, in order to enable its disposal on the first part  301  and/or its stretching the second part  302  can comprise a sloping zone  329  adjacent to its central hole. 
         [0047]    The second part  302  covers the surface of the first part  301  on which it is disposed, so that this ensures that the part of the valve seat  30  that comes into contact with the surface  102  of the valve body  100  that surrounds the through hole  13  is the second part  302  and in no circumstances the first part  301 . The second part  302  thus preferably comprises a first zone  321  that is substantially horizontal and adjacent to its central hole and which covers the zone of the first part  301  disposed between the columns  311  and  312 , a second zone  322  that is a substantially vertical wall and covers the surface of the outer column  312  of the first zone  301  that is facing the central column  311  of the first part  301 , and a third zone  323  that is substantially horizontal and covers the outer surface of the outer column  312 . The length of the central column  311  of the first part  301  is such that the second zone  322  of the second part  302  faces it, a ring-shaped housing  324  being defined between them. If the first part  301  does not comprise the outer column  312 , the second part  302  may not comprise the zones  322  and  323 , a ring-shaped housing  324  not being defined additionally. 
         [0048]    The third part  303 , shown by way of example in  FIG. 11 , is disposed in the ring-shaped housing  324  defined between the central column  311  of the first part  301  and the second zone  322  of the second part  302 , and comprises a central hole that is passed through by the central column  311  of the first part  301 . The first part  301  can comprise a groove in the outer surface of the central column  311  in order to house one end of the third part  303 , both parts  301  and  303  thus being connected together, although the diameter D 1  of the central column  311  of the first part  301  is preferably greater than the diameter D 3  of the central hole of the third part  303 , so that the third part  303  withstands an elastic deformation when it is disposed in the ring-shaped housing  324 , and exerts a pressure on the central column  311  of the first part  301 . The third part  303  is thus firmly joined to the first part  301  and prevents the second part  302  from coming away. Preferably, the diameter D 3  of the central hole of the third part  303  is between approximately 5% and approximately 15% smaller than the diameter D 1  of the central column  311  of the first part  301 . For example, the diameter D 3  may be 10% smaller than the diameter D 1 , the diameter D 3  being equal to 4.5 millimetres and the diameter D 1  equal to 5 millimetres. In addition, in order to enable its disposal on the second part  302  and/or its deformation the third part  303  can comprise a sloping zone  339  adjacent to its central hole. 
         [0049]    In addition, the third part  303  presses on the second part  302  making it even more difficult for the second part  302  to come away from the first part  301 . The third part  303  can also comprise a substantially vertical outer wall  330 , on the end opposite the end that is in contact with the central column  311  of the first part  301 . Preferably, the third zone  323  of the second part  302  is at a height greater than the outer wall  330  of the third part  303  and the central column  311  of the first part  301 , thereby ensuring the contact of said second part  302  with the surface  102  of the valve body  100  that surrounds the through hole  13 . If, with the second part  302 , a ring-shaped housing  324  is not defined, the third part  303  can be disposed on top of the second part  302 , in which case it would not comprise the outer wall  330  or preferably the second part  302  would comprise a housing, not shown in the Figures, where the third part  303  would be disposed. 
         [0050]    In order to enable the insertion of the parts  302  and  303  and therefore the assembly of the valve seat  30 , the central column  311  of the first part  301  comprises an end  319  in the form of a bevel, said end  319  corresponding with the free end of the first part  301 . In addition, the height H 1  of the central column  311  is greater than the height H 2  formed by the parts  302  and  303  when they are disposed in the ring-shaped housing  313  and  324  respectively, so that the correct fixing of both parts  302  and  303  in said position is ensured. 
         [0051]    The assembly of the valve seat  30  is explained below. Firstly, the second part  302  is disposed in the ring-shaped housing  313  defined in the first part  301 , exerting a pressure on it. The third part  303  is then disposed in the ring-shaped housing  324  defined between the central column  311  of the first part  301  and the second zone  322  of the second part  302 , exerting a pressure on it. Once assembled, the valve seat  30  is disposed in the required part of the valve  300 . 
         [0052]    The use of the aforementioned valve seat  30  is not restricted to a valve  300  as illustrated in the figures, it being capable of also being disposed in any other electromagnetic valve, preferably a gas valve. 
         [0053]    A second aspect relates to an assembly method for a gas valve  300  that comprises a valve member with a valve seat to prevent or allow the passage of gas through it and actuation means that are adapted to keep the valve seat in an open position in which it allows the passage of gas and which are supplied from the outside of the valve. In the method the actuation means, preferably comprising at least one coil and a core, are assembled, the actuation means is housed in the valve member, the valve member with the actuation means is disposed on a metal printed circuit board, and the valve member is soldered to the printed circuit board. 
         [0054]    The method may also be used to assemble a valve  300  such as the one described in the first aspect, in any of its embodiments and/or configurations.