Valve drive device, its control method and pump

A control method for a valve drive device comprising:

• providing the valve drive device, wherein the valve drive device comprises:
• a motor;
• a rotational member which is rotated by the motor;
• a linearly moving member which is engaged with the rotational member;
• a converting mechanism for converting rotation of the rotational member into linear movement to linearly move the linearly moving member;
• a diaphragm valve which is formed of an elastic body for opening or closing an opening part based on the linear movement of the linearly moving member;
• and
• an urging member for closing the opening part through the diaphragm valve which is abutting with the opening part in an urging state;
• wherein the converting mechanism converts rotation of the rotational member into linear movement of the linearly moving member by engaging the rotational member and the linearly moving member with each other and closing the opening part with the diaphragm valve in a state that the rotational member and the linearly moving member are in a non-engagement state;
• driving the motor to move the linearly moving member to a position where the diaphragm valve is abutted with and closes the opening part by the urging member;
• and
• stopping the motor at a position where the rotational member and the linearly moving member are in a non-engagement state.

A pump comprising:

• an inflow path in communication with an inflow opening;
• a pump chamber which is connected with the inflow path;
• a pump mechanism which is arranged in the pump chamber;
• a plurality of outflow paths which are extended from the pump chamber and are respectively in communication with a plurality of outflow openings;
• and
• a plurality of valve drive devices, wherein one valve drive device is disposed in the inflow path and the remainder of the plurality of valve drive devices are disposed in each of the plurality of outflow paths, and wherein each valve drive device comprises:
• a motor,
• a rotational member which is rotated by the motor;
• a linearly moving member which is engaged with the rotational member;
• a converting mechanism for converting rotation of the rotational member into linear movement to linearly move the linearly moving member;
• a diaphragm valve which is formed of an elastic body for opening or closing an opening part based on the linear movement of the linearly moving member;
• and
• an urging member for closing the opening part through the diaphragm valve which is abutting with the opening part in an urging state;
• wherein the converting mechanism converts rotation of the rotational member into linear movement of the linearly moving member by engaging the rotational member and the linearly moving member with each other and closing the opening part with the diaphragm valve in a state that the rotational member and the linearly moving member are in a non-engagement state.