Child safety seat and side impact protection mechanism thereof

1. A side impact protection mechanism provided at a backrest of a child safety seat and comprising a side impact protection block movably fitted to the backrest and having a folding position in which the side impact protection block is inwardly folded in the backrest and an unfolding position in which the side impact protection block is outwardly unfolded from the backrest, wherein the side impact protection mechanism further comprises a self-locking structure fitted to the side impact protection block or the backrest, the self-locking structure automatically moves to a position where the self-locking structure blocks the side impact protection block in the unfolding position from switching to the folding position when the side impact protection block is switched from the folding position to the unfolding position, and the backrest and the side impact protection block shields the self-locking structure to block a release operation of the self-locking structure by an operator;

wherein the self-locking structure comprises a self-locking member fitted to the backrest or the side impact protection block and being telescopically slidable, and a self-locking reset member providing a reset force for a telescopically slidable movement of the self-locking member, the self-locking reset member has a constant tendency to drive the self-locking member to slide in an extending direction to a position that blocks the side impact protection block in the unfolding position from switching to the folding position;

wherein the side impact protection block comprises a side impact protection block body pivoted to the backrest and a blocking member slidable to a blocking position or an avoidance position on the side impact protection block body, the blocking member projects out of the side impact protection block body to be in a blocking position that blocks against the backrest in a folding direction when the side impact protection block switches to the unfolding position, meanwhile the self-locking member slides to a position that blocks the side impact protection block in the unfolding position from switching to the folding position under an action of the self-locking reset member, the blocking member is retracted into the side impact protection block body to be in the avoidance position that is free from blocking against the backrest in the folding direction when the side impact protection block is in the folding position, and the self-locking member is pushed by the backrest to be in a retracted state in which the self-locking reset member is elastically deformed.

2. The side impact protection mechanism of claim 1 , wherein the self-locking reset member is an elastic member provided between the self-locking member and the side impact protection block or the backrest on which the self-locking member is located.

3. The side impact protection mechanism of claim 2 , wherein the side impact protection block is pivoted to the backrest.

4. A side impact protection mechanism provided at a backrest of a child safety seat and comprising a side impact protection block movably fitted to the backrest and having a folding position in which the side impact protection block is inwardly folded in the backrest and an unfolding position in which the side impact protection block is outwardly unfolded from the backrest;

wherein the side impact protection mechanism further comprises a self-locking structure fitted to the side impact protection block or the backrest, the self-locking structure automatically moves to a position where the self-locking structure blocks the side impact protection block in the unfolding position from switching to the folding position when the side impact protection block is switched from the folding position to the unfolding position, and the backrest and the side impact protection block shields the self-locking structure to block a release operation of the self-locking structure by an operator;

wherein the self-locking structure comprises a self-locking member fitted to the backrest or the side impact protection block and being telescopically slidable, and a self-locking reset member providing a reset force for a telescopically slidable movement of the self-locking member, the self-locking reset member has a constant tendency to drive the self-locking member to slide in an extending direction to a position that blocks the side impact protection block in the unfolding position from switching to the folding position;

wherein the self-locking member is positioned in the backrest, the self-locking member is pushed by the side-impact protection block to be in a retracted state in which the self-locking reset member is elastically deformed when the side impact protection block is positioned in the folding position, and the self-locking member is free from being pushed by the side impact protection block and slides to a position that blocks the side impact protection block in the unfolding position from switching to the folding position when the side impact protection block is positioned in the unfolding position;

wherein the backrest is provided with a metal sheet, the self-locking member inserts through the metal sheet, and the self-locking reset member is provided between the self-locking member and the metal sheet.

5. The side impact protection mechanism of claim 1 , wherein the self-locking member is fitted to the blocking member, and a telescopically slidable direction of the self-locking member intersects a sliding direction of the blocking member.

6. The side impact protection mechanism of claim 1 , wherein the side impact protection block further comprises a blocking reset member that has a constant tendency to drive the blocking member to slide to the blocking position.

7. The side impact protection mechanism of claim 6 , wherein the blocking reset member is an elastic member provided between the blocking member and the side impact protection block body.

8. The side impact protection mechanism of claim 1 , wherein an end of the blocking member positioned in front in an outwardly sliding direction has an inclined surface inclined with respect to the sliding direction of the blocking member, and the inclined surface of the blocking member is positioned in front of the blocking member in the pivotally unfolding direction of the side impact protection block.

9. The side impact protection mechanism of claim 1 , wherein the blocking member is a blocking block that exposes from the backrest when the side impact protection block is positioned in the unfolding position.

10. The side impact protection mechanism of claim 1 , wherein the self-locking member is a pin member or a block member.

11. A side impact protection mechanism provided at a backrest of a child safety seat, the side impact protection mechanism comprising:

a side impact protection block movably fitted to the backrest and having a folding position in which the side impact protection block is inwardly folded in the backrest and an unfolding position in which the side impact protection block is outwardly unfolded from the backrest;

a self-locking structure fitted to the side impact protection block or the backrest;

wherein the self-locking structure is configured to move to a position that blocks the side impact protection block in the unfolding position from switching to the folding position when the side impact protection block is switched from the folding position to the unfolding position;

wherein the backrest and the side impact protection block shields the self-locking structure to block a release operation of the self-locking structure by an operator;

wherein the self-locking structure comprises a self-locking member fitted to the backrest or the side impact protection block and being telescopically slidable, and a self-locking reset member providing a reset force for a telescopically slidable movement of the self-locking member, the self-locking reset member has a constant tendency to drive the self-locking member to slide in a extending direction to a position that blocks the side impact protection block in the unfolding position from switching to the folding position; and

wherein an end of the self-locking member positioned in front in the extending direction has an inclined surface inclined with respect to the extending direction of the self-locking member, the inclined surface of the self-locking member is positioned in front of the self-locking member in a pivotally unfolding direction of the side impact protection block, and the self-locking member is in a retracted state in which the self-locking reset member is elastically deformed when the side impact protection block is positioned in the folding position.

12. The side impact protection mechanism of claim 11 , wherein the self-locking member is located on the side impact protection block, and the self-locking member is pushed by the backrest to be in a retracted state in which the self-locking reset member is elastically deformed when the side impact protection block is positioned in the folding position.

13. The side impact protection mechanism of claim 11 , wherein the backrest is correspondingly provided with a lock fitting part that is locked with the self-locking member when the side impact protection block is in the unfolding position, and the backrest is further provided with a stopper for enclosing the lock fitting part and laterally shielding the self-locking member.

14. The side impact protection mechanism of claim 13 , wherein the lock fitting part has a groove structure.

15. The side impact protection mechanism of claim 4 , wherein the metal sheet has a “Y” shape.

16. A child safety seat comprising a seat part and a backrest fitted with the seat part, wherein the child safety seat further comprises the side impact protection mechanism; the side impact protection comprises:

a side impact protection block movably fitted to the backrest and having a folding position in which the side impact protection block is inwardly folded in the backrest and an unfolding position in which the side impact protection block is outwardly unfolded from the backrest; and

a self-locking structure fitted to the side impact protection block or the backrest;

wherein the self-locking structure is configured to move to a position that blocks the side impact protection block in the unfolding position from switching to the folding position when the side impact protection block is switched from the folding position to the unfolding position;

wherein the backrest and the side impact protection block shields the self-locking structure to block a release operation of the self-locking structure by an operator;

wherein the self-locking structure comprises a self-locking member fitted to the backrest or the side impact protection block and being telescopically slidable, and a self-locking reset member providing a reset force for a telescopically slidable movement of the self-locking member, the self-locking reset member has a constant tendency to drive the self-locking member to slide in a extending direction to a position that blocks the side impact protection block in the unfolding position from switching to the folding position;

wherein the self-locking reset member is an elastic member provided between the self-locking member and the side impact protection block or the backrest on which the self-locking member is located; and

wherein the backrest is provided with a metal sheet, the self-locking member inserts through the metal sheet, and the elastic member is provided between the self-locking member and the metal sheet.

17. The child safety seat of claim 16 , further comprising a base for detachably fitting and connecting the seat part.