Extrusion molding machine for producing ceramic molding

An extrusion molding machine for producing a ceramic molding, comprising a screw extruder having a housing and an extruding screw incorporated in the housing and provided with a shaft portion and a lead portion spirally wound about the shaft portion, and a material introduction portion which is adapted to introduce a ceramic material into the screw extruder, wherein the material introduction portion is provided with a casing which has an introduction passage connected to the inside of the housing of the screw extruder and an opening through which the ceramic material is charged, and a single introduction screw provided in the introduction passage, said introduction screw being in the form of a cone whose diameter is gradually reduced toward the front end thereof and being provided with a lead portion wound in a direction opposite to the lead portion of the extruding screw, said introduction screw being arranged, so that the lead portion of the introduction screw is engaged by the lead portion of the extruding screw substantially in a non-contact state at an engagement portion, said introduction screw and said extruding screw being rotated so that the ceramic material is moved in a direction opposite to the opening at the engagement portion.