PURPOSE: To reduce the manhours of drilling, etc., and the number of parts by connecting an oiling space provided facing the low pressure side passage of a hydraulic circuit to the central portion of the hydraulic circuit and simultaneously making it possible to arrange an oiling plug in the oiling part space.
CONSTITUTION: A hole 10 for connecting to a central portion a passage 6 being a low pressure side circuit bored in a hydraulic circuit block 1, opens toward an oiling part space 20 bored from the top of the hydraulic circuit block 1, and in this oiling part space 20 an opening 21 is bored in alignment with said hole 10, and there an oiling plug 22 is attached. With such constitution, the hole 10 at least conncenting the passage 6 to the central portion can be formed through the opening 21 by means of drilling utilizing the oiling part space 20, and it is enough to fit the oiling plug 22 in the opening 21 when its mission is over. Accordingly, it is possible to make the amount of machining such as drilling, etc., minimum, and to reduce the manhours of machining and the number of parts.
SAKAI SEIJI
TAKAYAMA SATOSHI
