US 12,312,219 B2
Control method for controlling retraction of boom, mechanical device and storage medium
Junhui Zou, Changsha (CN); Guoliang Liu, Changsha (CN); and Wei Shi, Changsha (CN)
Assigned to HUNAN SINOBOOM INTELLIGENT EQUIPMENT CO., LTD., Changsha (CN)
Filed by HUNAN SINOBOOM INTELLIGENT EQUIPMENT CO., LTD., Changsha (CN)
Filed on Jun. 24, 2024, as Appl. No. 18/751,759.
Application 18/751,759 is a continuation of application No. PCT/CN2022/086492, filed on Apr. 13, 2022.
Claims priority of application No. 202210048197.0 (CN), filed on Jan. 17, 2022.
Prior Publication US 2024/0343530 A1, Oct. 17, 2024
Int. Cl. F15B 11/05 (2006.01); B66C 23/00 (2006.01); F15B 13/02 (2006.01)
CPC B66C 23/54 (2013.01) [F15B 11/055 (2013.01); F15B 13/026 (2013.01); F15B 2211/253 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A control method for controlling retraction of a boom, applied to a hydraulic system which combines retraction of the boom by self-wight with retraction of the boom by pressure, the hydraulic system comprising: a pressure retraction motor, a pressure retraction proportional valve and a self-weight retraction proportional valve that are sequentially connected, the boom with non-rod cavity being connected to the self-weight retraction proportional valve, and the boom with rod cavity being connected to the pressure retraction motor and the pressure retraction proportional valve, wherein the control method comprises:
when the boom is retracted, controlling the self-weight retraction proportional valve to be at a maximum opening;
obtaining an actual speed at which the boom is retracted;
controlling a rotation speed of the pressure retraction motor to rise or an opening degree of the pressure retraction proportional valve to increase when the actual speed is less than a preset speed, wherein
after the step of controlling the rotation speed of the pressure retraction motor to rise or the opening degree of the pressure retraction proportional valve to increase when the actual speed is less than the preset speed, the control method further comprises:
determining whether the actual speed is still less than the preset speed, and if the actual speed is still less than the preset speed, controlling the rotation speed of the pressure retraction motor to keep a highest rotation speed or controlling the opening degree of the pressure retraction proportional valve to be a maximum state; and
controlling the rotation speed of the pressure retraction motor to reduce or the opening degree of the pressure retraction proportional valve to decrease when the actual speed is greater than the preset speed.