Disengagement prevention structure for pipe connecting portion

A disengagement prevention structure for a pipe connecting portion, comprising:

• a collar having a divided structure and surrounding a fitting connection part between a spigot portion of a first pipe portion on one side and a socket portion of a second pipe portion on the other side in a sealed state, the collar being externally mounted over both the spigot portion of the first pipe portion and the socket portion of the second pipe portion;
• a seal part for sealing between an inner peripheral surface of a second pipe support portion and an outer peripheral surface of the spigot portion, the seal part being provided in one end portion of the collar in a pipe axis direction, and an other seal part for sealing between an inner peripheral surface of a pipe support portion and an outer peripheral surface of the socket portion, the other seal part being provided in an other end portion of the collar in the pipe axis direction;
• a first disengagement blocking part, which allows a relative disengagement movement to a disengaged state where connection of the socket portion and the spigot portion is released, and blocks, by contact, a relative disengagement movement beyond a certain level between the socket portion and the collar in the disengaged state, the first disengagement blocking part being provided at a location where the collar and a socket portion side of the second pipe portion on the other side face each other in a pipe axis direction;
• and
• a second disengagement blocking part provided with a retaining part in which falling-off resistance between the retaining part and an outer peripheral surface of the spigot portion increases according to a disengagement movement of the spigot portion, the second disengagement blocking part being provided on a pipe support portion side on one end side in the pipe axis direction of the collar,
• wherein the other seal part provided in the other end portion of the collar in the pipe axis direction comprises two circumferential direction groove portions formed along the pipe circumferential direction on the inner surface of the second pipe support portion at an interval in the pipe axis direction, each of the circumferential direction groove portions receiving a seal member.

A disengagement prevention structure for a pipe connecting portion, comprising:

• a collar having a divided structure and surrounding a fitting connection part between a spigot portion of a first pipe portion on one side and a socket portion of a second pipe portion on the other side in a sealed state, the collar being externally mounted over both the spigot portion of the first pipe portion and the socket portion of the second pipe portion;
• a first disengagement blocking part, which allows a relative disengagement movement to a disengaged state where connection of the socket portion and the spigot portion is released, and blocks, by contact, a relative disengagement movement beyond a certain level between the socket portion and the collar in the disengaged state, the first disengagement blocking part being provided at a location where the collar and a socket portion side of the second pipe portion on the other side face each other in a pipe axis direction;
• and
• a second disengagement blocking part provided with a retaining part in which falling-off resistance between the retaining part and an outer peripheral surface of the spigot portion increases according to a disengagement movement of the spigot portion, the second disengagement blocking part being provided on a pipe support portion side on one end side in the pipe axis direction of the collar,
• wherein the first disengagement blocking part is provided by a disengagement blocking portion configured to come into contact with an outer peripheral surface of the socket portion, the disengagement blocking portion being formed on an inner peripheral surface side of a second pipe support portion side on an other end side in the pipe axis direction of the collar and at a location shifted toward a center side in the pipe axis direction of the collar with respect to a seal part for sealing between the inner peripheral surface of the second pipe support portion and the outer peripheral surface of the second pipe portion, and
• wherein a distance from the contact position of the disengagement blocking portion to a first end of a seal holding groove of the seal part, proximal to the contact position, is configured to be larger than a thickness dimension in the pipe axis direction in an inner partition wall of partition walls on both sides in the pipe axis direction of a second seal holding groove of second a seal part formed on an inner peripheral surface of the pipe support portion on the one end side, the second seal part being configured to seal between the inner peripheral surface of the pipe support portion and an outer peripheral surface of the first pipe portion.