Combined working machine and combined working method

A combined working machine that can carry out cutting and grinding, the combined working machine comprising:

• a base frame that has a sloped surface;
• a first headstock that is installed on the sloped surface;
• a first main spindle that is provided on the first headstock horizontally and rotatably, and holds a base end of a workpiece;
• a second headstock that is installed on the sloped surface to be opposed to the first headstock;
• a second main spindle that is provided on the second headstock movable in a Z-axis direction that is an axial direction of the first main spindle and an X-axis direction that is perpendicular to the Z-axis and parallel to the sloped surface, and is configured to hold a distal end of the workpiece or a base end of another workpiece;
• a tool head that is installed on the sloped surface on one side of the first headstock;
• a tool head body that is provided in the tool head movably in the X-axis direction and the Z-axis direction, and has a tool attachment base to which a cutting tool is attached exchangeably;
• a grinding head that is installed on the sloped surface on another side of the first headstock;
• a grinding head body that is provided in the grinding head movably in the X-axis direction and the Z-axis direction, and supports a rotary shaft that is rotatable and inclined to both of the X-axis direction and the Z-axis direction,
• wherein
• a grinding wheel for grinding is exchangeably attached to the rotary shaft of the grinding head;
• and
• a dresser provided on the first headstock for dressing the grinding wheel,
• wherein the first headstock has an outer circumferential surface that is centered on an axial center of the first main spindle,
• the outer circumferential surface has a first portion and a second portion,
• wherein, in a Y-axis direction that is perpendicular to both of the X-axis direction and the Z-axis direction, a distance from the sloped surface to the first portion is smaller than a distance from the sloped surface to the axial center of the first main spindle, and a distance from the sloped surface to the second portion is larger than the distance from the sloped surface to the axial center of the first main spindle,
• the dresser is located outward from a chuck that is provided at one end of the first main spindle in the Z-axis direction with respect to the axial center of the first main spindle, and
• the dresser is located only at the second portion among the first and second portions.