US 12,325,089 B2
Gas control system and method for a reflow soldering furnace
Shenghu Yan, Suzhou New District (CN); Peng Shu, Suzhou New District (CN); and Dong Zhang, Suzhou New District (CN)
Assigned to Illinois Tool Works Inc., Glenview, IL (US)
Appl. No. 17/271,465
Filed by Illinois Tool Works Inc., Glenview, IL (US)
PCT Filed Aug. 30, 2019, PCT No. PCT/US2019/049113
§ 371(c)(1), (2) Date Feb. 25, 2021,
PCT Pub. No. WO2020/047442, PCT Pub. Date Mar. 5, 2020.
Claims priority of application No. 201811013268.3 (CN), filed on Aug. 31, 2018.
Prior Publication US 2021/0339330 A1, Nov. 4, 2021
Int. Cl. B23K 3/08 (2006.01); B23K 1/00 (2006.01); B23K 1/008 (2006.01); B23K 35/38 (2006.01); G05D 27/02 (2006.01); B23K 101/42 (2006.01)
CPC B23K 3/08 (2013.01) [B23K 1/0016 (2013.01); B23K 1/008 (2013.01); B23K 35/383 (2013.01); G05D 27/02 (2013.01); B23K 2101/42 (2018.08)] 7 Claims
OG exemplary drawing
 
1. A gas control system for a reflow soldering furnace, a furnace chamber of said reflow soldering furnace comprising a preheating zone and a cooling zone and containing a gas, said gas comprising oxygen and a working gas, wherein said gas control system comprises:
an oxygen detecting device positioned to come into contact with said gas in said furnace chamber for detecting an oxygen concentration in said furnace chamber wherein said oxygen detecting device generates an oxygen concentration signal based on the detected oxygen concentration;
a first intake valve device in fluid communication with said preheating zone and a working gas source, and a second intake valve device in fluid communication with said cooling zone and said working gas source, wherein said first intake valve device is configured to controllably establish fluid communication between said preheating zone and a working gas source, and said second intake valve device is configured to controllably establish fluid communication between said cooling zone and said working gas source; and
a controller configured to:
determine a regulation set value (RV) of an oxygen concentration, said regulation set value (RV) being greater than a target set value (TV) of an oxygen concentration, the target set value (TV) being set based on an oxygen concentration requirement for a soldering process;
regulate a flow rate of the working gas inputted into said furnace chamber by:
when an actual detection value (DV) reflected by said oxygen concentration signal is greater than said regulation set value (RV), increasing the opening extent of said first intake valve device and that of said second intake valve device; and
when an actual detection value (DV) reflected by said oxygen concentration signal is smaller than said regulation set value (RV), controlling the opening extent of said first intake valve device to remain at a preset value and regulate the opening extent of said second intake valve device based on comparing the actual detection value (DV) to the target set value (TV).