US 12,129,878 B2
Air control circuit equipped with safety feature
Akira Enzaki, Tsukubamirai (JP)
Assigned to SMC CORPORATION, Chiyoda-ku (JP)
Appl. No. 18/252,911
Filed by SMC CORPORATION, Chiyoda-ku (JP)
PCT Filed Oct. 21, 2021, PCT No. PCT/JP2021/038850
§ 371(c)(1), (2) Date May 15, 2023,
PCT Pub. No. WO2022/107540, PCT Pub. Date May 27, 2022.
Claims priority of application No. PCT/JP2020/042879 (WO), filed on Nov. 18, 2020.
Prior Publication US 2023/0417262 A1, Dec. 28, 2023
Int. Cl. F15B 20/00 (2006.01); F15B 11/06 (2006.01); G05D 16/20 (2006.01)
CPC F15B 20/008 (2013.01) [F15B 11/06 (2013.01); G05D 16/2024 (2019.01); G05D 16/2033 (2013.01)] 7 Claims
OG exemplary drawing
 
1. An air control circuit including a safety function, comprising:
a main air line in which two external-pilot-operated electromagnetic valves are connected in series; a pilot air line that supplies pilot air to the two electromagnetic valves; and a pilot control line that switches the pilot air line between a supply state to supply the pilot air to the two electromagnetic valves and an exhaust state to exhaust the pilot air from the two electromagnetic valves,
wherein the two electromagnetic valves in the main air line are two-position valves that have a first position for when turned off and a second position for when turned on, and the two electromagnetic valves are connected so that, when both of the two electromagnetic valves are in the first position, the electromagnetic valves shut an air source and an air device from each other and exhaust air in the air device through one of the electromagnetic valves, when both of the two electromagnetic valves are in the second position, the electromagnetic valves connect the air source and the air device to each other to supply air from the air source to the air device, and when one of the two electromagnetic valves is in the first position and the other one of the two electromagnetic valves is in the second position, the electromagnetic valves shut the air source and the air device from each other and exhaust air in the air device through the electromagnetic valve in the first position,
wherein, an air operation valve having a first position where the pilot air line is in the supply state and a second position where the pilot air line is in the exhaust state is connected to the pilot air line, and
wherein the pilot control line is connected to the air source or disconnected from the air source by the two electromagnetic valves, when both of the two electromagnetic valves are in the first position and when both of the two electromagnetic valves are in the second position, the pilot control line is disconnected from the air source to hold the air operation valve in the first position where the pilot air line is in the supply state, and when one of the two electromagnetic valves is in the first position and the other one of the two electromagnetic valves is in the second position, the pilot control line is connected to the air source through the two electromagnetic valves to switch the air operation valve to the second position where the pilot air line is in the exhaust state with control air supplied from the air source.