"Power Rangers" actor Hector David Jr. is cooling his heels behind bars after he pled guilty and was sentenced on Wednesday for assaulting a man in Idaho last year.

Hector, who played the role of the "Green Ranger" in the superhero franchise, pled guilty to misdemeanor battery in a Canyon County Court and was sentenced to 180 days in jail … according to new legal docs.

The judge suspended 135 days of the sentence, meaning he only has to serve 45 days in the clink but will have to keep his nose clean when he gets out to avoid further time behind bars. The judge also placed Hector on 2 years of supervised probation and ordered him to complete 100 hours of community service.

As TMZ first reported in July ... Hector got into an argument with an elderly man -- who used a walker -- over a parking spot in Nampa, Idaho. The situation escalated when authorities say Hector shoved the man to the ground, though he was not seriously injured.

Hector then jumped into his truck and drove off, but cops later identified him with help from the community and a judge issued an arrest warrant for him. Prosecutors eventually charged Hector with battery in late July.