Patent ID: 11905775
Assignee: SHENZHEN UNIVERSITY
Field: Civil engineering (Other fields)
Classification: CPC E | IPC E

Claim 7:
8. The driving system for a core drilling rig according to claim 7, wherein a fluid channel C (43) is disposed between the central rod (14), the lock pin (22) and the locking rod (12), a side wall of the locking rod (12) is provided with an inflow hole (1241), the fluid channel B (42) communicates with the fluid channel C (43) through the inflow hole (1241), the fluid channel C (43) communicates with the fluid channel D (44),
wherein the connecting pipe (21) includes a pressure-relief section (212) and a choke section (213), the lock pin (22) and the choke section (213) are in a sealing fit, and an inner diameter of the choke section (213) is shorter than an inner diameter of the pressure-relief section (212), the pressure-relief section (212) is provided with a pressure-relief hole (2121) that is a through hole, shearing plunger (26) is disposed in the fluid channel B (42), and an inner diameter of the shearing plunger (26) is longer than outer diameters of both the lock pin (22) and the locking rod (12), the shearing plunger (26) is connected to the lock body (11) through an end shearing pin (25), the shearing plunger (26) includes a shearing section (261) and a recoil section (262), an outer wall of the shearing section (261) is in a sealing fit with an inner wall of the lock body (11), and an outer diameter of the recoil section (262) is equal to an inner diameter for the front part of the pressure-relief hole (2121) in the pressure-relief section (212).