Abstract: A printing device, a printing machine, and a box making machine are provided with printing cylinders on which printing plates can be mounted, ink supply rolls that are placed on the upstream or downstream sides of the printing cylinders in a sheet-conveying direction and that can be in contact with the printing cylinders, ink supply units that can supply ink to the ink supply rolls, first covers that cover the upper parts of the printing cylinders in the vertical direction and that can be opened and closed, and footholds that cover the vertically upper parts of the ink supply rolls and that can be operated by an operator.

Abstract: A blow-by gas recirculation device that, while having a structure in which a passage for blow-by gas is in a head cover and an oil separator, an increase in size of an engine is suppressed and the risk of the freezing is mostly avoided by shortening the length of an external pipe for the blow-by gas. Therefore, the blow-by gas recirculation device guides blow-by gas from a crankcase to an intake passage through an in-cover gas passage formed inside a head cover. An oil separator that traps and removes oil from the blow-by gas is attached to the inside of the head cover. A pressure regulating valve is provided on the outlet side of the in-cover gas passage in the head cover. A separator outlet, which is an outlet for the blow-by gas in the oil separator, is overlapped on a blow-by gas inlet portion of the pressure regulating valve.

Abstract: A blow-by gas recirculation device that, while having a structure in which a passage for blow-by gas is in a head cover and an oil separator, an increase in size of an engine is suppressed and the risk of the freezing is mostly avoided by shortening the length of an external pipe for the blow-by gas. Therefore, the blow-by gas recirculation device guides blow-by gas from a crankcase to an intake passage through an in-cover gas passage formed inside a head cover. An oil separator that traps and removes oil from the blow-by gas is attached to the inside of the head cover. A pressure regulating valve is provided on the outlet side of the in-cover gas passage in the head cover. A separator outlet, which is an outlet for the blow-by gas in the oil separator, is overlapped on a blow-by gas inlet portion of the pressure regulating valve.

Abstract: As a further improvement of the technique of minimizing or preventing excessive cooling of an oil separator, an effective blow-by gas heating apparatus which minimizes or solves the problems due to frozen blow-by gas in an engine externally equipped with an oil separator is provided. The blow-by gas heating apparatus includes: a heat emitting structure abutted onto an oil separator configured to trap and remove oil from blow-by gas. The heat emitting structure has a heat emitting case including inside a passage for engine cooling water. The heat emitting case includes a ceiling wall being in surface-contact from below with a bottom surface of the oil separator.

Abstract: As a further improvement of the technique of minimizing or preventing excessive cooling of an oil separator, an effective blow-by gas heating apparatus which minimizes or solves the problems due to frozen blow-by gas in an engine externally equipped with an oil separator is provided. The blow-by gas heating apparatus includes: a heat emitting structure abutted onto an oil separator configured to trap and remove oil from blow-by gas. The heat emitting structure has a heat emitting case including inside a passage for engine cooling water. The heat emitting case includes a ceiling wall being in surface-contact from below with a bottom surface of the oil separator.