Method and apparatus for forming belt-like rubber member

An apparatus for forming a belt-like rubber member, the apparatus comprising:

• an extruder that extrudes rubber from a die;
• a forming surface on which the rubber extruded from the die is affixed;
• an extruder moving device that moves the extruder close to or away from the forming surface;
• a forming-surface moving device that moves the forming surface in a direction parallel to the forming surface;
• and
• a control unit that controls the extruder, the extruder moving device, and the forming-surface moving device,
• wherein the control unit
• brings the die of the extruder close to the forming surface until a distance from the forming surface to the die reaches an extrusion start distance, starts extrusion of the rubber from the die, starts movement of the forming surface in the direction parallel to the forming surface,
• forms the front end having a wedge-shaped cross section by gradually increasing an extrusion amount of the rubber from zero to a predetermined extrusion amount in a predetermined time, gradually increasing a movement speed of the forming surface from zero to a predetermined movement speed in the predetermined time, and gradually increasing the distance from the forming surface to the die from the extrusion start distance to a predetermined distance that is equal to a desired thickness of the annular rubber member in the predetermined time,
• forms an intermediate part having the desired thickness by maintaining the extrusion amount of the rubber at the predetermined extrusion amount, maintaining the movement speed of the forming surface at the predetermined movement speed, and maintaining the distance from the forming surface to the die at the predetermined distance, and
• forms the rear end having a wedge-shaped cross section by gradually decreasing the extrusion amount of the rubber from the predetermined extrusion amount to zero in the predetermined time, gradually decreasing the movement speed of the forming surface from the predetermined movement speed to zero in the predetermined time, and gradually decreasing the distance from the forming surface to the die from the predetermined distance to an extrusion end distance in the predetermined time.