| 摘要 |
PROBLEM TO BE SOLVED: To maximally utilize an effect of a pressure cancel mechanism, in a two-stage electromagnetic valve.SOLUTION: As a configuration for maintaining a state that a changeover valving element 5 is seated immediately after the seat release of an opening/closing valving element 8, there is employed a configuration that the changeover valving element 5 is pressed by a pressing member until a time point immediately after the seat release of the opening/closing valving element 8, a pressure of a valve chamber 2 being introduced to the changeover valving element 5 at this time point. According to this configuration, the changeover valving element 5 is not necessary to receive a pressure in a full-closed state. That is, it is not necessary to reduce a pressure-receiving diameter of the opening/closing valving element 8 more than a pressure-receiving diameter of the changeover valving element 5. Therefore, it becomes possible to design the pressure-receiving diameter of the opening/closing valving element 8 irrespective of the pressure-receiving diameter of the changeover valving element 5, and a degree of freedom of the design is increased. Accordingly, since an effect of a pressure cancel mechanism is maximally utilized, it becomes possible to make equal the pressure-receiving diameter of the opening/closing valving element 8 and an effective pressure-receiving diameter of a diaphragm 11. Thus, the effect of the pressure cancel mechanism can be maximally utilized. |
