Apparatus for operating water gate

An apparatus for operating a water gate, said apparatus comprising:

• a door of the water gate provided in a water channel to run and stop water;
• and
• an operating mechanism for vertically operating said door, said operating mechanism comprising:
• a pressure receiving plate fixed to said door via an operating rod;
• a guide portion for guiding the vertical movement of said pressure receiving plate;
• an upper air bag and a lower air bag provided on the upper and lower sides of said pressure receiving plate, respectively;
• an air compressor for sending air into each of said upper air bag and said lower air bag through an air feed pipe and a flow rate regulating valve;
• a discharging flow rate regulating valve for discharging air from said upper air bag and said lower air bag;
• and
• a four-way change-over valve provided between said upper air bag and said lower air bag and said air compressor, flow rate regulating valve, and discharging flow rate regulating valve and which is adapted to switch the air sent into said upper air bag and said lower air bag,
• wherein said four-way change-over valve is adapted to control the opening and closing of said door by:
• sending compressed air into said lower air bag by using air from said air compressor by operating to move said pressure receiving plate, whereby said door is raised,
• sending compressed air into said upper air bag by switching to move said pressure receiving plate, whereby said door is lowered, and
• being set at a neutral position, and wherein a shutoff valve provided in an air feed pipe for said lower air bag is closed, whereby said door is held at a predetermined position.