Flight Instructor with student reported a NMAC that required evasive action to avoid collision with an aircraft at a non-towered airport. The Instructor stated this is not the first encounter at this location due to no communication from the aircraft with other aircraft in the traffic pattern.

Narrative

I was CFII on instructional flight IFR with a student on filed IFR flight plan doing the RNAV 36 into CHN touch and go. We were cleared for the approach and switched over to CTAF prior to IAF when field was in sight. We made appropriate non-towered radio calls communicating our position; distance and intentions. We heard 1 other call for traffic holding short 36 waiting for us to arrive; an aircraft of the same type as Aircraft Y. On short final around MDA approx. 400 feet I saw Aircraft Y making left traffic turning base and attempting to land. This was around XA00Z and dusk was setting in. At this time we had already placed our strobes; position and anti collision lights on as well as our landing lights. The traffic turning base in danger of hitting us was not making any radio calls and was not on ADS-B. I had to take controls from my student and aggressively dip below the path trajectory of the encroaching Aircraft Y to ensure safety. The aircraft holding short made radio calls to someone in the pattern telling them to turn their radio on and that they were cutting us off. We did a touch and go and departed the pattern to the north in the upwind. About 5 minutes later while still monitoring the CTAF we heard another aircraft having to go missed after another of the same type as Aircraft Y cut them off short final. That pilot advised them of the extreme danger that they were putting themselves and everyone else in risk of. That makes 2 close calls for aircraft on short final being cut off in less than 10 minutes! I am making this report because on Day 0 I was making another RNAV approach into CHN and a similar incident occurred where around dusk a same type aircraft not making radio calls and not on ADS-B cut me off on short final about 200 feet above TDZ and less than .5 miles away from the runway where I had to take evasive maneuvers and immediately go missed to avoid a sure mid air after the aircraft cut me off and dipped below my approach path. This almost seemed intentional both times. There is no possibly way these type aircraft do not see us on short final especially with the radio calls we are making. There appear to be at least 2-3 of these type aircraft in a group there maneuvering frequently. I hope there is something that can be looked into because in the past 2 trips I have been there in less than a week these type of aircraft have almost caused 3 mid airs!