The ornamental design for an injectiondevice, as shown and described.
FIG. 1 is a top perspective view of an injection device, showing the new design.
FIG. 2 is a front elevational view of the injection device.
FIG. 3 is a rear elevational view of the injection device.
FIG. 4 is a right side elevational view of the injection device.
FIG. 5 is a left side elevational view of the injection device.
FIG. 6 is a top view of the injection device; and,
FIG. 7 is a bottom view of the injection device.
Portions of the design shown in broken lines are visible through transparent components of the injection device and form no part of the design as claimed.