Shielding apparatus for lower end of injection needle and injection device

A shielding apparatus for a lower end of an injection needle, comprising:

• a needle holder (1), used for mounting of an injection needle (2) of an injection device and mounted on an insulin pen of the injection device, wherein the needle holder (1) is provided with a moving groove (11), a limit groove (12) and a first guiding bevel (13) on an inner wall, the moving groove (11) extending along an axial direction of the needle holder (1), the limit groove (12) being located on a side of an upper end of the moving groove (11) and being communicated with the moving groove (11) through the first guiding bevel (13), and an end of the first guiding bevel (13) connected to the limit groove (12) being higher than an end of the first guiding bevel (13) connected to the moving groove (11);
• and
• a shielding cylinder (3), mounted in the needle holder (1) and allowing the injection needle (2) to penetrate through, wherein a limit block (31) for placing in the limit groove (12) is provided on a side wall of the shielding cylinder (3), the limit block (31) being located below the first guiding bevel (13);
• when the needle holder (1) is mounted on the insulin pen, the shielding cylinder (3) abuts against the insulin pen and moves upwardly to allow the limit block (31) in the limit groove (12) to enter the moving groove (11) along the first guiding bevel (13);
• and after the needle holder (1) is separated from the insulin pen, the limit block (31) moves downwardly along the moving groove (11) to allow the shielding cylinder (3) to cover and shield the lower end of the injection needle (2).