In this paper, we propose PaTeCon, a novel method for maintaining the consistency of temporal facts, which describe events occurring at specific times in knowledge graphs (KGs). Existing works rely on manually enumerated temporal constraints to detect temporal consistency problems, which are labor-intensive and cause granularity problems. PaTeCon automatically generates temporal constraints without human intervention by exploiting patterns and statistical information in the knowledge graph. In this paper, we introduce two new benchmarks built by optimizing the performance of PaTeCon and annotating Wikidata and Freebase, and demonstrate the effectiveness of PaTeCon through experiments.