Quick connector

1. A quick connector coupling to a cylindrical pipe body having an annular projection formed projecting radially outward at a location axially spaced from a distal end, comprising:

a cylindrical housing body;

a retainer integrally formed with or coupled to the housing body, having a shape capable of allowing the pipe body to be inserted therethrough in an axial direction from an opening end of the retainer, and engaging the annular projection of the pipe body inserted into the retainer from the opening end in the axial direction to regulate disengagement of the pipe body in the axial direction; and

a checker confirming that the annular projection of the pipe body is in a state of being engaged by the retainer by sliding in a set radial direction with respect to the retainer to move from a first position to a second position,

the retainer comprising:

a retainer body having a first engagement portion and a second engagement portion; and

a retainer diameter-expanding elastically-deformable claw provided on the retainer body, having a C-shape capable of expanding diametrically by elastic deformation, allowing the annular projection of the pipe body to pass through in the axial direction by expanding diametrically, and engaging with the annular projection in the axial direction by restoring an original shape after the annular projection of the pipe body has passed through in the axial direction,

the checker comprising:

a checker diameter-expanding elastically-deformable claw formed in a C-shape capable of expanding diametrically by elastic deformation, preventing sliding with respect to the retainer body from the first position toward the set radial direction by being engaged by the first engagement portion in a not diameter-expanded state, being expanded diametrically by the annular projection of the pipe body after which has passed through the retainer diameter-expanding elastically-deformable claw in the axial direction, and capable of sliding with respect to the retainer body from the first position toward the second position in the set radial direction by being released from the engagement with the first engagement portion in a diameter-expanded state; and

a checker-axis direction elastically-deformable claw having a distal-end side formed flexibly deformable in the axial direction, maintaining a state of being engaged by the second engagement portion of the retainer body by having the deflective deformation prevented by the retainer diameter-expanding elastically-deformable claw in a state in which the retainer diameter-expanding elastically-deformable claw is expanded diametrically, preventing sliding with respect to the retainer body from the first position toward the set radial direction by being engaged by the second engagement portion of the retainer body, and capable of sliding with respect to the retainer body from the first position to the second position in the set radial direction by being capable of being released from the engagement with the second engagement portion of the retainer body in a state in which the retainer diameter-expanding elastically-deformable claw has restored its original shape,

wherein the set radial direction along which the checker slides with respect to the retainer from the first position to the second position is a push-in direction of the checker with respect to the retainer;

an opening side of the C-shape of the retainer diameter-expanding elastically-deformable claw is in a direction opposite to the push-in direction; and

the checker has a release portion diametrically expanding the retainer diameter-expanding elastically-deformable claw by sliding with respect to the retainer from the second position to a third position in the set radial direction.

2. The quick connector according to claim 1 , comprising a release regulator regulating sliding of the checker toward the third position with respect to the retainer body in a state in which the checker is positioned at the second position with respect to the retainer body, and allowing the checker to be slidable with respect to the retainer body toward the third position when a force is applied.

3. The quick connector according to claim 1 , wherein

the retainer is integrally formed with the housing body; and

the retainer comprises a stopper regulating diameter expansion of the retainer diameter-expanding elastically-deformable claw when amount of diameter expansion of the retainer diameter-expanding elastically-deformable claw has reached a set amount.

4. The quick connector according to claim 1 , wherein

the retainer body comprises an open end seat member forming an opening end of the retainer and forming the second engagement portion; and

the checker comprises a gap intervening member formed on a radially inner side of the checker-axis direction elastically-deformable claw with a slit intervening therebetween, intervening in an axial gap between the open end seat member of the retainer body and the retainer diameter-expanding elastically-deformable claw during a period when the checker moves from the first position to the second position with respect to the retainer.

5. The quick connector according to claim 1 , wherein the retainer and the checker comprise a guide regulating a relative rotation and guiding relative sliding in the set radial direction.

6. The quick connector according to claim 1 , wherein the checker-axis direction elastically-deformable claw comprises a pair of checker-axis direction elastically-deformable claws respectively corresponding to two ends of the retainer diameter-expanding elastically-deformable claw.