Abstract: A broaching method for finishing an outer peripheral surface of a resin layer of a resin-coated lobe-type rotor for a rotary fluid machine of a Roots type, which includes the steps of forming, with a leading grooving cutter, at least one chip-breaker groove in the outer peripheral surface of the resin layer, such that the chip-breaker groove extends in a broaching direction parallel to an axis of rotation of the rotor. The method further includes the steps of finishing at least a portion of the outer peripheral surface of the resin layer with a trailing finish cutter having a cutting edge contour corresponding to the portion of the outer peripheral surface of the resin layer, which is finished by the finish cutter after the chip-breaker groove is formed therein by the grooving cutter. A composite broach or formed broach having the grooving and finish cutters is fed such that the grooving cutter leads the finish cutter in the broaching direction.

Abstract: A broaching machine for broaching an outer surface of a rotor of a rotor assembly which includes a support shaft projecting from opposite end faces of the rotor for supporting the rotor rotatably about its axis. The machine includes a backing plate for backing the rotor assembly such that one of the end faces of the rotor is held in contact with backing plate. The circumferential position of the rotor assembly is established by a positioning pin which extends from the backing plate, and engages a hole formed in the rotor. The machine includes a first centering device which has a center engageable with one of opposite ends of the support shaft so as to hold and center the support shaft at the one end, and a second centering device having a V-block and a retainer block which are engageable with the other end of the support shaft so as to hold and center the support shaft at the other end.

Abstract: Method and apparatus for broaching an outer surface of a resin layer of a resin-coated part whose external side surface is coated with the resin layer, wherein a backing plate is used to back the resin-coated part such that the plate is held in contact with an end face of the part at which a movable broach terminates a broaching cut in a direction along the outer surface of the resin layer. The backing plate has an external profile similar to a cutting edge contour of the broach. The backing plate is positioned on a work bed of the broaching apparatus such that its external profile is inwardly spaced from the cutting edge contour of the broach a plane perpendicular to the direction of movement of the broach. The backing plate, which forms a part of a work-holding fixture, serves to protect the resin layer from breakage, chipping or other defects at the end of a broaching pass along the outside of the resin-coated part.

Abstract: A broaching method for finishing an outer peripheral surface of a resin layer of a resin-coated lobe-type rotor for a rotary fluid machine of a Roots type, which includes the steps of forming, with a leading grooving cutter, at least one chip-breaker groove in the outer peripheral surface of the resin layer, such that the chip-breaker groove extends in a broaching direction parallel to an axis of rotation of the rotor. The method further includes the steps of finishing at least a portion of the outer peripheral surface of the resin layer with a trailing finish cutter having a cutting edge contour corresponding to the portion of the outer peripheral surface of the resin layer, which is finished by the finish cutter after the chip-breaker groove is formed therein by the grooving cutter. A composite broach or formed broach having the grooving and finish cutters is fed such that the grooving cutter leads the finish cutter in the broaching direction.

Abstract: An intake heating apparatus of an internal combustion engine, comprising a hollow heater vessel which is placed in an intake passage of the engine and which comprises an inner pipe, an outer pipe in which said inner pipe is press-fitted, a PTC element holder located between the inner and outer pipes for holding peripherally spaced PTC elements, and an annular elastic electrode located between the PTC elements and the outer pipe. The PTC element holder has holes in which the PTC elements are held. The lower edges of the holes are off-set from the lower end of the elastic electrode.

Abstract: An intake heating apparatus of an internal combustion engine, comprising a hollow heater vessel which is placed in an intake passage of the engine and which comprises an inner pipe, an outer pipe in which said inner pipe is press-fitted, peripherally spaced PTC elements located between the inner and outer pipes, and an annular elastic electrode located between the PTC elements and the outer pipe. The improvement comprises means for preventing the PTC elements from being broken when and after the inner pipe is press-fitted in the outer pipe.

Abstract: An intake heating device of an engine, comprising a hollow heater vessel placed in the intake passage. The heater vessel comprises an inner pipe, an outer pipe, and a plurality of PTC elements. The inner pipe and the outer pipe are interconnected to each other in such a way that the upper end and the lower end of the inner pipe are bent outwards and pressed onto the outer wall of the outer pipe.

Abstract: An intake heating device of an engine, comprising a hollow heater vessel placed in the intake passage. The heater vessel comprises an inner pipe, an outer pipe, and a plurality of PTC elements inserted between the inner pipe and the outer pipe. The outer wall of the inner pipe is surrounded by a belt-like insulating member having a plurality of rectangular holes. The PTC elements are inserted into the rectangular holes and held in a predetermined position by the insulating member.

Abstract: A flow control valve for an exhaust gas recirculation apparatus is provided with an exhaust gas pressure control means for maintaining a predetermined constant pressure of exhaust gas to be recirculated. The flow control valve is adpated to control an amount of the exahust gas to be directed to the pressure controlling means, for performing an ideal EGR operation. A detailed design of the flow control valve is provided for solving the problems which may occur during the actual use of the flow control valve.