Timing adjustment valve and suckback valve provided with same

A timing adjustment valve comprising:

• a pilot body provided with a first port, a second port, and a drive port and formed with an internal flow passage extending between the first port and the second port;
• a check valve mechanism which allows a fluid in the internal flow passage to flow from the first port to the second port and prevents the fluid in the internal flow passage from flowing from the second port to the first port;
• and
• a timing adjustment mechanism which opens and closes the internal flow passage by supplying and discharging a drive fluid to and from the drive port,
• wherein the timing adjustment mechanism is arranged in parallel with the check valve mechanism in the internal flow passage and is configured to allow the fluid to flow between the first port and the second port when the pressure of the drive fluid supplied to and discharged from the timing adjustment mechanism through the drive port is equal to or less than a predetermined value.