US 11,745,402 B2
High-precision and high-efficiency injection mold for high-aspect-ratio double-layer cylindrical plastic part and molding method using the same
Yaqing Liu, Taiyuan (CN); Ruikui Du, Taiyuan (CN); Guizhe Zhao, Taiyuan (CN); and Kai Wen, Taiyuan (CN)
Assigned to NORTH UNIVERSITY OF CHINA, Taiyuan (CN); and SHANXI ZHONGBEI NEW MATERIAL TECHNOLOGY CO., LTD., Taiyuan (CN)
Filed by NORTH UNIVERSITY OF CHINA, Taiyuan (CN); and SHANXI ZHONGBEI NEW MATERIAL TECHNOLOGY CO., LTD., Taiyuan (CN)
Filed on Feb. 4, 2023, as Appl. No. 18/164,581.
Claims priority of application No. 202210714970.2 (CN), filed on Jun. 23, 2022.
Prior Publication US 2023/0173723 A1, Jun. 8, 2023
Int. Cl. B29C 45/26 (2006.01); B29C 45/16 (2006.01); B29C 45/73 (2006.01); B29L 9/00 (2006.01)
CPC B29C 45/2606 (2013.01) [B29C 45/1635 (2013.01); B29C 45/2669 (2013.01); B29C 45/7312 (2013.01); B29L 2009/00 (2013.01)] 9 Claims
OG exemplary drawing
 
1. An injection mold for a high-aspect-ratio double-layer cylindrical plastic part, comprising:
a support base plate;
wherein a movable mold fixing frame and a movable mold base plate are successively arranged at a middle of a lower surface of the support base plate through positioning screws; a lower core mold accommodating cavity is provided at a center of a top surface of the support base plate; a lower core mold is provided in the lower core mold accommodating cavity, and fits the lower core mold accommodating cavity; the lower core mold is provided with a lower semicircular cavity for matchingly accommodating an outer die barrel; a first side of the lower semicircular cavity is open, and a second side of the lower semicircular cavity is provided with a first end wall; the first end wall is provided with a lower semicircular notch for fitting an inner die rod; an upper surface of the lower core mold is provided with a positioning protrusion, a lower feeding groove, and a remaining groove; a push plate is arranged in the movable mold fixing frame; at least one reset guide rod and a push rod are fixedly arranged on the push plate; the push rod penetrates the lower core mold to enter the remaining groove; the at least one reset guide rod penetrates the support base plate; and the movable mold base plate is provided with a push plate hole;
a stationary mold plate is arranged above a middle of the support base plate; an upper core mold accommodating cavity is provided at a center of a lower surface of the stationary mold plate; an upper core mold is provided in the upper core mold accommodating cavity, and fits the upper core mold accommodating cavity; the upper core mold is provided with an upper semicircular cavity for matchingly accommodating the outer die barrel; a first side of the upper semicircular cavity is open, and a second side of the upper semicircular cavity is provided with a second end wall; the second end wall is provided with an upper semicircular notch for fitting the inner die rod; a lower surface of the upper core mold is provided with a positioning groove and an upper feeding groove; the upper feeding groove is connected to a branch runner; the branch runner penetrates to a surface of the stationary mold plate; a stationary mold base plate is arranged on an upper surface of the stationary mold plate; the stationary mold base plate is provided with a pouring port, and a hot runner bushing is arranged in the pouring port; a bottom end of the hot runner bushing is connected to an inlet of a primary runner on the upper surface of the stationary mold plate; the stationary mold base plate is provided with at least one guide pillar; and the at least one guide pillar penetrates through the stationary mold plate and the support base plate in sequence; and
after the lower core mold and the upper core mold are clamped, the lower feeding groove and the upper feeding groove together form a feeding channel, the lower semicircular cavity and the upper semicircular cavity together form a circular cavity, the first end wall and the second end wall together form an end wall at a first side of the circular cavity, and the lower semicircular notch and the upper semicircular notch together form a circular hole for the inner die rod to pass through; a positioning block is arranged at a second side of the circular cavity, and is fixed on the support base plate; a height of an inner ring surface of the positioning block protruding from a side wall surface of the circular cavity is less than or equal to a thickness of a molded plastic part; the inner ring surface of the positioning block is in clearance fit with an outer surface of the outer die barrel; a first fixed seat is arranged at a first end of the support base plate; a first moving device is arranged on the first fixed seat; a first pull rod is arranged at a moving end of the first moving device, and is connected to an end of the outer die barrel through a first mounting block; a second fixed seat is arranged at a second end of the support base plate; a second moving device is arranged on the second fixed seat; and a second pull rod is arranged at a moving end of the second moving device, and is connected to an end of the inner die rod through a second mounting block.