Balancer device for internal combustion engine

A balancer device for an internal combustion engine, comprising:

• an idler shaft holding an idler sprocket around which a drive chain is wound, and an idler gear which is rotatable with the idler sprocket;
• a pair of balancer shafts which have balancer weights for generating a vibratory force by a rotation force transmitted from the idler gear;
• an upper housing disposed between the pair of balancer shafts and the internal combustion engine;
• and
• a lower housing which comes in contact with the upper housing via a mating surface, and rotatably holds the pair of balancer shafts in a space formed between the upper housing and the lower housing;
• wherein the upper housing includes:
• a support part which supports one end portion in an axial direction of the idler shaft;
• a fixing portion which is provided at a position away from the support part, and comes in contact with the internal combustion engine;
• and
• a first reinforcing part which is disposed to connect between the support part and the fixing portion, and reinforces a part on a lower housing side of the support part.