Abstract:
The solenoid valve of this invention comprises an electromagnet with a rotator disposed in at least one side of the valve body. The shaft of the rotator is provided with the valve members to open or close the valve port. The solenoid valve has advantages such as high attraction force, less power, and is easy to continuously control.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a gas solenoid valve and, more particularly, to a closed rotary gas solenoid valve for gas flow control. 
     2. Description of Related Art 
     A guardless solenoid electromagnet structure employed in a current gas solenoid valve has a flatter pull characteristics, has a smaller attraction force, has a large power loss, typically cannot execute concurrent closing of the gas pipeline, and has the characteristics shown in FIG.  1 . Another type of gas solenoid valve adopts a solenoid guarded electromagnet, which has a rather steep pull characteristics as shown in FIG.  2 . Due to the constraint of the power consumption and bulk factors, when a larger flow is needed, an aperture enlargement of the gas solenoid valve and elongation of the operating stroke are required. A further type of the gas solenoid valve employs an epsilon structural clapper electromagnet having a rather steep pull characteristics. When the operating clearance is enlarging, its attraction attenuates rapidly, and the solenoid valve is unable to realize the linear regulation of gas via the continuous current control, while the electromagnet can only reside in on-off state via the input of the square wave current to the coil, to attain the goal of the gas regulation through a variation of on-off time ratio of the electromagnet by changing the duty cycle of the on-off time. Using this switch regulation mode, a gas pulsation shall be generated in regulation, thereby the problems of the solenoid valve abrasion due to the frequently mechanical vibration of the electromagnet, and the intrinsic vibration frequency of the electromagnet, must be lower than the input current frequency occurred. If a closing function is concurrently operated by the solenoid valve, since at this time the electromagnetic attraction force is a minimum, difficulties shall appear when a closing elastic force is needed. The force exerted on the valve member by the compressed gas and the viscosity force of the rubber valve member have to be overcome. When more gas is required, diameters of the valve port and rubber valve member should be enlarged, the armature stroke has to be elongated, and the power loss, weight and volume of the electromagnet must be increased. At this moment, normal operation cannot be performed due to the extremely low intrinsic vibration frequency of the electromagnet. 
     SUMMARY OF THE INVENTION 
     The main object of the invention is to provide a rotary gas solenoid valve having a low power loss, a large aperture and a long operating stroke. 
     Another object of the invention is to provide a double closure continuous controlled gas solenoid valve. 
     A rotary gas solenoid valve provided by the invention comprises a valve casing installed with an inlet and an outlet. A guarded rotary electromagnet is mounted on a side of the valve casing. The guarded rotary electromagnet comprises an iron core, a coil, a rotary armature, and a seating. A valve support is fastened at the position of an axial end of the rotary armature shaft of the electromagnet corresponding to the inlet or outlet valve port. A valve member is mounted on the valve support. 
     Another rotary gas solenoid valve provided by the invention comprises a valve casing installed with an inlet, an outlet, a coil, a rotary armature, and a seating. A valve support is fastened at the position of the axial end of the rotary armature shaft of the electromagnet corresponding with the inlet or outlet valve port. A valve member is mounted on the valve support. A guardless rotary electromagnet is also mounted on another side of the valve casing. The guardless rotary electromagnet comprises an iron core, a coil, a rotary armature, and a seating. A valve support is fastened at the position of an axial end of the rotary armature shaft of the electromagnet corresponding with the inlet or outlet valve support. 
     According to the rotary gas solenoid valve, a reset spring is mounted in the guarded or guardless electromagnet, one end of the spring being fixed on the iron core or the seating and another end of the spring being mounted on a side of the rotary armature or an arm fastened with the axial end of the armature shaft. 
     According to the rotary gas solenoid valve, a rubber-sealing ring is mounted therein between the shaft of the rotary-type armature and a bearing positioning hole of the valve casing. 
     According to the rotary gas solenoid valve, an adjusting screw is installed therein on the reset spring mounted in the guardless rotary electromagnet. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Incorporated with the drawings, a preferred embodiment of the invention is described in detail in which: 
     FIG. 1 shows pull characteristics of a guardless solenoid electromagnet employed in the prior art; 
     FIG. 2 shows pull characteristics of a guarded solenoid electromagnet employed in the prior art; 
     FIG. 3 shows pull characteristics of the rotary electromagnet; 
     FIG. 4 is a structural schematic of a first embodiment of the invention; 
     FIG. 5 is a side view of FIG. 4 with a valve casing removed; 
     FIG. 6 is a structural schematic of a second embodiment of the invention; 
     FIG. 7 is a side view of FIG. 6 with a valve casing removed; 
     FIG. 8 is a structural schematic of a third embodiment of the invention; and 
     FIG. 9 is a side view of FIG. 8 with a valve casing removed. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG.  4  and FIG. 5, there is shown a schematic of a first embodiment of a rotary gas solenoid valve of the invention, which consists of a valve casing  14  and a guarded electromagnet  12  mounted on a side of the valve casing  14 . An inlet and outlet valve port  11  is installed at the inner chamber of the valve casing  14 . A positioning hole  26  of a bearing case  19  of an armature shaft  17  is opened on a side plane of the valve casing  14  with the bearing case  19  of electromagnet shaft  17  and an axial end of shaft  17  being mounted and positioned here. A rubber sealing ring  20  is mounted on the shaft  17  in the positioning hole  26 . The guarded rotary electromagnet  12  comprises an iron core  25 , a coil  3 , a rotary armature  24 , and a seating  18 . The guarded rotary electromagnet  12  is fixed on a side plane of the valve casing  14  via its iron core  25  and seating  18 . A reset spring  21  is installed between an arm fastened with its rotary armature  24  or the axial end of the armature shaft  17  and the seating  18  or the iron core  25 . A valve support  15  is fastened at the position of the axial end of shaft  17  corresponding to the outlet valve port  11 . Valve member  16  is mounted on the valve support  15 . A guard  27  and the seating  18  are merged into a whole and are locate don the positions corresponding to the two convex cambered surfaces of the rotary armature  24  respectively. In a case of de-energization, the inlet and outlet valve ports are in the closed state due to the action of the reset spring. After coil  3  is energized, the opening and closing can be controlled for the outlet valve port  11  by the rotary gas solenoid valve described above. 
     Both side end faces of the rotary armature  24  have an equidistant clearance with respect to the corresponding side faces of the iron core, and the guarded rotary electromagnet has a large initial attraction force, its pull characteristics being shown at the curve  31  in FIG.  3 . After put on operation, the coil current can be reduced or converted to a coil having a smaller rated current and enough attraction is still retained. 
     A second embodiment of the invention is shown in FIG.  6 . and FIG. 7. A rotary gas solenoid valve of the embodiment is a double closure continuously controlled gas solenoid valve, which consists of a valve casing  14  and rotary electromagnets  12 ,  22  mounted on both sides of valve casing  14 . A burning gas outlet valve port  11  and a burning gas inlet port  13  are installed on the upper and lower portions of the inner chamber in the valve casing  14 . Positioning holes  26  of a bearing case  19  of an armature shaft  17  are opened on both side symmetrical planes of the valve casing  14  respectively with the shaft bearing case  19  of the rotary electromagnets  12 ,  22  and the axial end of the shaft  17  being mounted and positioned here. A rubber sealing ring  20  is mounted on the shaft  17  in the positioning hole  26 . The rotary electromagnets  12 ,  22  are fixed on both side planes of the valve casing  14  via seating  18 . Reset springs  21  are mounted on the two rotary electromagnets  12 ,  22 , respectively, one end being mounted on an iron core  25  or the seating  18  and another end being mounted on a side of a rotary armature  24  or an arm fastened with the axial end of armature shaft  17 . With regards to the guardless rotary electromagnet  22  used for the closing or the regulation, an adjusting screw  23  is also mounted on the reset spring  21  to correct the systemic error formed by various factors. On installation, the rubber-sealing ring  20  is mounted on the shaft in the positioning hole. A valve support  15  is fastened at the position of the axial end of the shaft  17  corresponding with the outlet valve port  11  or the inlet valve port  13 , and a valve member  16  is mounted on the valve support  15 . In the embodiment, the guarded rotary electromagnet  12  is mounted the right side of the valve casing  14  shown in FIG.  6  and carries out the opening and closing control to the inlet valve port  13 . The guardless rotary electromagnet  22  is mounted on the left side of the valve casing shown in FIG.  6  and carries out the closing to the outlet valve port  11  and the gassing continuous control. That is, the guarded rotary electromagnet  12  is used for the first stage closure, while the guardless rotary electromagnet  22  is used for the second stage closure, thereby the double stage closure of the solenoid valve and the continuously controlled gas flow are performed. 
     In a case of the rotary electromagnet de-energization, the inlet valve port  13  and the outlet valve port  11  are in a closed state due to the action of the reset spring, thereby the double closure action is performed. When power is turned on in operation, one of the valve ports is fully opened by the guarded rotary electromagnet  12 , while the guardless rotary electromagnet  22  controls the gas flow of another valve port via its coil current variation. The mounting positions of the guarded and guardless rotary electromagnets on the valve casing can be interchanged. 
     Referring to FIG.  8  and FIG. 9, there is shown a schematic of a third embodiment of a rotary gas solenoid valve of the invention, which consists of a valve casing  14  and a guardless rotary electromagnet  22  mounted on a side of the valve casing  14 . An inlet and outlet valve port  11  is installed in the inner chamber of the valve casing  14 , and a positioning hole  26  of a bearing case  19  of an armature shaft is opened on a side plane of the valve casing  14 . The bearing case  19  of the electromagnet shaft  17  and the axial end of the shaft  17  are mounted and positioned here, and a rubber-sealing ring  20  is mounted on the shaft  17  in the positioning hole  26 . The guardless rotary electromagnet  22  comprises an iron core  25 , a coil  3 , a rotary armature  24 , and a seating  18 . The rotary armature  24  is supported on the seating  18  fastened to the iron core  25  via the shaft  17  and the bearing case  19 . The guardless rotary electromagnet  22  is fixed on a side plane of the valve casing  14  via the iron core  25  and seating  18 . A reset spring  21  is installed between the rotary armature  24  and seating  18 . An adjusting screw  23  is also installed on the reset spring  21  for correction of the systemic error formed by various factors. A valve support  15  is fastened at the position of the axial end of shaft  17  corresponding with the outlet valve port  11 , and a valve member  16  is mounted on the valve support  15 . After coil  3  is energized, it can carry out the closure or continuous control to the gassing of the outlet valve port  11  via variation of the coil current. The end faces on both sides of the armature  24  have an equidistant clearance with respect to the corresponding side faces of the iron core  25 . Consequently, it has the features of a flat pull characteristics and a large initial attraction force. The coil current can be easily changed, the operating stroke can be adjusted and a quasi-linearly continuous control of the operating stroke can be carried out, as shown in the curve  32  of FIG.  3 . This electromagnet is suitable for fabrication of the closed gas regulating valve. 
     In a case of de-energization, the outlet valve port  11  in a closed state by the action of the reset spring  21 , thereby a closing action can be provided. 
     The feature of a large initial attraction in the rotary electromagnet has been employed in the invention. Thereby, at the moment of starting, enough of an attraction force can be used to overcome the closing force of the reset spring, the force exerted on the rubber valve member by the compressed-gas, and the adhesion between the rubber valve member and valve port. If the rotary electromagnet was employed to elongate the operation stroke, the valve member stroke could be easily extended only by elongation for length of the convex cambered faces on both sides of the rotary armature and the corresponding concave cambered faces on both sides of the iron core, with no need to increasing the power loss of the electromagnet. 
     In contrast to the prior art, the following advantages are provided: (1) low power loss, large gas flow, and facilitate of continuous control; and (2) since no wearing parts exist, good reliability, safety, and longer service life can be attained.