Abstract: An exhaust manifold for an internal combustion engine wherein exhaust ducts connected to respective engine cylinders are formed of discrete pipe members. A united section has an upstream divergent portion connected to the exhaust ducts and a downstream convergent portion to exhaust pipes. An internal space is defined in the downstream convergent portion and located intermediately between adjacent internal passages in the downstream convergent portion to communicate them with each other. An opening is formed in the peripheral wall of the downstream convergent portion at a location positionally corresponding to the internal space. A flange member has a boss formed thereon and being larger in size than the opening and disposed in face-to-face contact with an outer surface of the peripheral wall of the downstream convergent portion. The boss has a through bore formed therein and aligned with the opening, through which an exhaust constituent concentration sensor is to be inserted.

Abstract: A swash-plate type compressor having a housing, a drive shaft rotatably supported by the housing, a swash-plate slantly secured on the drive shaft, and a plurality of pistons fitted in a cylinder bore formed in correspondence to each of the pistons parallelly to the drive shaft and provided with a pair of concave spherical surface formed therein. Each of the pistons is engaged with the swash-plate via a pair of shoes of substantially semi-spherical shape. The shoe has a convex spherical surface which is in sliding contact with the concave spherical surface of the piston and a flat-side surface which is in sliding contact with the swash-plate. The flat-side surface consists of a chamfered surface annularly formed on the outer portion thereof and a centrally left substantially flat surface with a diameter as large as about 60-90% of that of the whole flat-side surface. The substantially flat surface is formed into an extremely gentle convex surface with a height less than 15 .mu.