Abstract: An injection piston drives a screw. An injection hydraulic cylinder drives the injection piston and is partitioned into first and second chambers. A first oil discharge port is disposed in the injection hydraulic cylinder to be blocked by a piston part when the piston part of the injection piston advances to a pressure-holding switching position, and discharges hydraulic oil from the second chamber. A second oil discharge port is disposed in the injection hydraulic cylinder to be capable of discharging hydraulic oil from the second chamber regardless of the position of the injection piston. The injection piston has first and second members. The joint of the first and second members is disposed at a position separated from an end of the piston part on a side of the second chamber by a predetermined distance.

Abstract: According to an embodiment, a method for manufacturing a joined metal member includes: disposing a first metal member inside a mold of an injection molding apparatus, the first metal member being made of a first metal material, unevenness being formed over a surface of the first metal member, and an oxide film being formed so as to cover the unevenness; and injecting a second metal material into the mold, and thereby molding a second metal member and joining the second metal member to the first metal member, the second metal material being, when it is injected into the mold, in a semi-molten state, or in a molten state in which a difference between a temperature of the second metal material and a liquidus temperature thereof is smaller than or equal to 30° C.

Abstract: According to an embodiment, a method for manufacturing a joined metal member includes: disposing a first metal member inside a mold of an injection molding apparatus, the first metal member being made of a first metal material, unevenness being formed over a surface of the first metal member, and an oxide film being formed so as to cover the unevenness; and injecting a second metal material into the mold, and thereby molding a second metal member and joining the second metal member to the first metal member, the second metal material being, when it is injected into the mold, in a semi-molten state, or in a molten state in which a difference between a temperature of the second metal material and a liquidus temperature thereof is smaller than or equal to 30° C.

Abstract: An injection piston drives a screw. An injection hydraulic cylinder drives the injection piston and is partitioned into first and second chambers. A first oil discharge port is disposed in the injection hydraulic cylinder to be blocked by a piston part when the piston part of the injection piston advances to a pressure-holding switching position, and discharges hydraulic oil from the second chamber. A second oil discharge port is disposed in the injection hydraulic cylinder to be capable of discharging hydraulic oil from the second chamber regardless of the position of the injection piston. The injection piston has first and second members. The joint of the first and second members is disposed at a position separated from an end of the piston part on a side of the second chamber by a predetermined distance.