Cutting insert, cutting tool, and method of manufacturing machined product using them

A cutting insert, comprising:

• an upper surface;
• a side surface;
• and
• a first cutting edge located at an intersection of the upper surface and the side surface, wherein
• the upper surface comprises a pair of raised parts located opposite to each other with a perpendicular bisector of the first cutting edge interposed therebetween,
• a top of each of the pair of raised parts comprises
• a first protrusion extending in a direction along the perpendicular bisector,
• a second protrusion extending in the direction along the perpendicular bisector, located on a side further away from the perpendicular bisector than the first protrusion, and located at a higher position than the first protrusion, and
• a concave curved surface extending in the direction along the perpendicular bisector and located between the first protrusion and the second protrusion, and each of the pair of raised parts is continuous with the first cutting edge.

A cutting insert, comprising:

• an upper surface;
• a side surface;
• and
• a first cutting edge located at an intersection of the upper surface and the side surface, wherein
• the upper surface comprises
• a pair of raised parts located opposite to each other with a perpendicular bisector of the first cutting edge interposed therebetween, and
• a middle inclined part between the pair of raised parts which is inclined and located at a higher position as the middle inclined part separates from the first cutting edge,
• a top of each of the pair of raised parts comprises
• a first protrusion extending in a direction along the perpendicular bisector, and
• a second protrusion extending in the direction along the perpendicular bisector, located on a side further away from the perpendicular bisector than the first protrusion, and located at a higher position than the first protrusion,
• the middle inclined part is located at a lower position than the first protrusion,
• at least one of the pair of raised parts further comprises an inclined surface inclined and located at a higher position as the inclined surface separates from the first cutting edge,
• an end portion of the middle inclined part located further away from the first cutting edge is located on an identical straight line together with an end portion of the inclined surface located on a side further away from the first cutting edge, or is located further rearward than the end portion of the inclined surface, in a top view, and
• the inclined surface comprises
• a first inclined surface located closer to the first cutting edge, and
• a second inclined surface which is located further rearward than the first inclined surface and is inclined at a smaller angle than the first inclined surface.