A self-locking internal damper for fuel injection systems for motor vehicles, comprising: a damper body having a closed chamber, each of two ends of the chamber in the length direction thereof having a straight plate section projecting therefrom, with a center line of the straight plate section passing through a center point of the chamber; two connecting portions located at ends of the two straight plate sections, respectively, at least one of the two connecting portions being a bent structure formed by extending and bending the straight plate section wherein the two straight plate sections and a centre plane of the chamber in the length direction thereof are located in the same plane, at least one of the connecting portions with a bent structure comprises: a first connecting portion, one end of the first connecting portion being connected to one of the straight plate sections, another end of the first connecting portion extending in a direction away from one of the straight plate sections, with an included angle between the first connecting portion and one of the straight plate sections; a second connecting portion, one end of the second connecting portion being connected to the other end of the first connecting portion, another end of the second connecting portion extending in a direction away from the first connecting portion, with an included angle between the first connecting portion and the second connecting portion; a third connecting portion, one end of the third connecting portion being connected to the other end of the second connecting portion, another end of the third connecting portion extending in a direction away from the second connecting portion, with an included angle between the second connecting portion and the third connecting portion; wherein the first connecting portion, the second connecting portion and the third connecting portion together form the bent structure, characterized in that the two connecting portions have the same structure, wherein the size of one of the connecting portions is larger than the size of the other connecting portion. a damper body having a closed chamber, each of two ends of the chamber in the length direction thereof having a straight plate section projecting therefrom, with a center line of the straight plate section passing through a center point of the chamber; two connecting portions located at ends of the two straight plate sections, respectively, at least one of the two connecting portions being a bent structure formed by extending and bending the straight plate section wherein the two straight plate sections and a centre plane of the chamber in the length direction thereof are located in the same plane, at least one of the connecting portions with a bent structure comprises: a first connecting portion, one end of the first connecting portion being connected to one of the straight plate sections, another end of the first connecting portion extending in a direction away from one of the straight plate sections, with an included angle between the first connecting portion and one of the straight plate sections; a second connecting portion, one end of the second connecting portion being connected to the other end of the first connecting portion, another end of the second connecting portion extending in a direction away from the first connecting portion, with an included angle between the first connecting portion and the second connecting portion; a third connecting portion, one end of the third connecting portion being connected to the other end of the second connecting portion, another end of the third connecting portion extending in a direction away from the second connecting portion, with an included angle between the second connecting portion and the third connecting portion; wherein the first connecting portion, the second connecting portion and the third connecting portion together form the bent structure, characterized in that the two connecting portions have the same structure, wherein the size of one of the connecting portions is larger than the size of the other connecting portion. a first connecting portion, one end of the first connecting portion being connected to one of the straight plate sections, another end of the first connecting portion extending in a direction away from one of the straight plate sections, with an included angle between the first connecting portion and one of the straight plate sections; a second connecting portion, one end of the second connecting portion being connected to the other end of the first connecting portion, another end of the second connecting portion extending in a direction away from the first connecting portion, with an included angle between the first connecting portion and the second connecting portion; a third connecting portion, one end of the third connecting portion being connected to the other end of the second connecting portion, another end of the third connecting portion extending in a direction away from the second connecting portion, with an included angle between the second connecting portion and the third connecting portion; wherein the first connecting portion, the second connecting portion and the third connecting portion together form the bent structure, characterized in that the two connecting portions have the same structure, wherein the size of one of the connecting portions is larger than the size of the other connecting portion.