Metering valve, high-pressure container, and asthma treatment device

A metering valve comprising:

• a high-pressure partition wall that forms part of a high-pressure container that isolates a storage region to be filled with a high-pressure fluid from an atmospheric pressure space;
• an internal partition wall that is arranged inside the high-pressure partition wall and forms a metering chamber partitioned from the storage region between the internal partition wall and the high-pressure partition wall;
• a stem that extends in a direction in which the high-pressure partition wall and the internal partition wall face each other, is linearly movably supported, and is biased toward the high-pressure partition wall to be positioned at an origin position;
• a first seal hole that penetrates the high-pressure partition wall so as to extend over the atmospheric pressure space and the metering chamber and has a first seal portion linearly movably supporting a first intermediate portion of the stem and closing a gap between the first seal hole and the stem;
• a second seal hole that penetrates the internal partition wall so as to extend over the metering chamber and the storage region and has a second seal portion linearly movably supporting a second intermediate portion of the stem and closing a gap between the second seal hole and the stem;
• a terminal-end-side stem internal flow path that is formed inside the stem and extends from a terminal end of the stem to the first intermediate portion, the terminal end being always positioned in the atmospheric pressure space;
• a starting-end-side stem internal flow path that is formed inside the stem and extends from a starting end of the stem to the second intermediate portion, the starting end being always positioned in the storage region;
• a terminal end discharge port that is provided in the terminal-end-side stem internal flow path and is open to the terminal end of the stem;
• a peripheral surface inlet port that is provided in the terminal-end-side stem internal flow path, is open to an outer peripheral surface of the first intermediate portion of the stem, is positioned to be closer to the atmospheric pressure space than to the metering chamber when the stem is arranged at the origin position, and is positioned in the metering chamber when the stem is moved to a metered quantity discharge position from the origin position;
• a starting end inlet port that is provided in the starting-end-side stem internal flow path and is open to the starting end of the stem;
• a peripheral surface discharge port that is provided in the starting-end-side stem internal flow path, is open to an outer peripheral surface of the second intermediate portion of the stem, is positioned in the metering chamber when the stem is arranged at the origin position, moves from the metering chamber to the storage region before the peripheral surface inlet port is positioned in the metering chamber while the stem is moving from the origin position to the metered quantity discharge position, and is positioned in the storage region when the stem is positioned at the metered quantity discharge position;
• a container-shaped seal member that has a pair of through-holes through which the stem penetrates, forms an inner surface of the internal partition wall, and covers an inner surface of the high-pressure partition wall facing the metering chamber;
• and
• a cup-shaped fixing member that has a cup shape, is fixed to the high-pressure partition wall so as to cover the container-shaped seal member, fixes the container-shaped seal member, and has a stem fitting portion to which the stem is fitted, wherein
• the first seal portion and the second seal portion are formed by ends of openings of the pair of through-holes of the container-shaped seal member,
• the container-shaped seal member is formed by integrally molding a cup portion that forms the internal partition wall and through which the second seal hole penetrates and a flange portion that covers an opening of the cup portion and through which the first seal hole penetrates so that the second seal hole and the first seal hole are coaxial, and
• the cup-shaped fixing member fixes the container-shaped seal member by sandwiching the flange portion of the container-shaped seal member between an end of an opening of the cup-shaped fixing member and the high-pressure partition wall.