Injection molding method for resin molding and method for specifying mold-clamping force

An injection molding method for a resin molding closes a stationary mold (201) with a movable mold (202) at a prescribed mold-clamping force and, after filling melted resin in a cavity (1) formed between the stationary mold (201) and the movable mold (202), performs pressure maintenance and cooling, and separates the stationary mold (201) from the movable mold (202). The injection molding method performs mold-clamping, filling, pressure maintenance, and cooling on the stationary mold (201) and the movable mold (202) using a previously specified mold-clamping force at which the pressure inside the cavity (1) during the cooling step is a minimum and which is based on a sample specified from among multiple samples (T1, T2, T3). 种树脂成型品的注射成型方法，以规定的合模力将固定模具(201)和可动模具(202)闭合，在形成于固定模具(201)和可动模具(202)之间的腔室(1)内填充熔融树脂，然后实施保压及冷却，将固定模具(201)和可动模具(202)分开。注射成型方法中，以根据冷却工序时的腔室(1)内的压力呈现出最小压力、而且从多个样本(T1、T2、T3)确定的样本而预先确定的合模力，对固定模具(201)和可动模具(202)实施合模、填充、保压及冷却。