To provide the satisfactory operating state of a flash valve without forming a burr within a bypass passage by forming an inclination in the part crossing a small passage of the bypass passage.
In the piston part 7 of this flash valve, a bypass passage 22 directing a control valve chamber 27 and a small passage 23 directing a pressure chamber are formed in cross. In this structure, an inclination is formed in the part crossing the small passage 23 of the bypass passage 22. According to this, burrs can be prevented from being formed within the bypass passage 22 when the small passage 23 is formed in cross to the bypass passage 22 by use of a pin. When the part changing in passage diameter within the small passage 23 is formed in radius, the pin is hardly broken, and the formation of the small passage 23 is facilitated.
AOKI MASAKI
HIRAIDE KEISUKE
