The invention relates to a method for coating a mechanically highly loaded surface (2) of a component (1) consisting of a hardened steel with a nitrogen and/or carbon component with an adherent or functional coating (4) for surface treatment, wherein a metallic binding material (5) is introduced into the surface (2) prior to the application of the adherent or functional coating (4) to create a graduated diffusion barrier zone (3) conforming to the surface with a proportion of metal nitride and/or metal carbide increasing towards the surface (2).

A coil component of an electromagnetic valve is made compact to achieve both low cost and improvement in sound vibration performance. Therefore, a high-pressure fuel pump of the present invention includes: a coil 3g; a magnetic core 3e that is arranged on a side opposite to a pressurizing chamber 11 with respect to a movable core 3h and attracts the movable core 3h when the coil 3g is energized; a yoke 3q arranged on a radially outer side of the coil 3g; a cover portion 3r that covers the coil 3g from an axially outer side; and a molded portion 17 that covers a radially outer side of the yoke 3q and an axially outer side of the cover portion 3r.

A high pressure pump includes a housing with a chamber formed inside and a flow control valve and a discharge check valve installed in the chamber; a piston installed to operate up and down in an assembly hall formed in the housing to compress fuel in the chamber to a high pressure; a cylinder forming a gap between an inner circumferential surface and the piston and guiding reciprocation of the piston; and a support member seated on a stepped surface of the housing to surround an outside of the cylinder and configured to elastically support the housing and the cylinder, thereby reducing friction while preventing fuel leakage between the piston and the cylinder.

Provided is a high-pressure fuel supply pump and a method of manufacturing thereof which can suppress the progress of corrosion and cavitation erosion even when the pressure becomes higher, or when biofuel or a fuel having a high oil content of biofuel is used. Therefore, the high-pressure fuel supply pump includes a discharge valve 51b that discharges fuel, and a discharge valve seat 51a on which the discharge valve 51b is seated. The base material of the discharge valve 51b and the discharge valve seat 51a is a steel material. On the surface of the discharge valve 51b, a Co-based alloy layer 70b and a Cr-enriched portion 70b1 having a higher Cr concentration than the surrounding Co-based alloy layer 70b are formed. The Co-based alloy layer 70a is formed on the surface of the discharge valve seat 51a.

A structure for attaching a metal diaphragm damper, includes a housing, a housing cover that cooperates with the housing to define a space, and a pair of diaphragms each formed in a disk shape, the pair of diaphragms having weld portions on an outer periphery side thereof, the weld portions being welded to each other in an annular shape to form the metal diaphragm damper of which inside is filled with gas, the metal diaphragm damper being attached to the housing and the housing cover so as to be disposed in the space between the housing and the housing cover. The pair of diaphragms is provided with outer peripheral portions on the outer peripheral side of the welded portions, and the outer peripheral portions of the pair of diaphragms are held by the housing and the housing cover in a thickness direction of the pair of diaphragms.

A fuel supply device includes a flange, a pump unit, a supporting pillar, and a boss. The flange is attached to an opening portion of a fuel tank. The supporting pillar supports a sub tank such that the sub tank is positioned closer to and away from the flange. The boss is fixed at the flange and an end of the supporting pillar is inserted into the boss. The boss is made of a material different from that of the flange. The boss includes a stress concentration portion that is preferentially broken when a force equal to or greater than a predetermined value is applied to an end portion of the supporting pillar in an axis perpendicular direction.

The invention relates to an electromagnetically controllable suction valve (1) for a high-pressure fuel pump (2), comprising a magnet assembly (3) and a hydraulic module (4), the hydraulic module (4) engaging at least in sections in an annular magnet coil (5) of the magnet assembly (3). According to the invention, a heat-conducting material (6) and/or a heat-conducting body (7) is/are arranged between the magnet coil (5) and the hydraulic module (4). The invention further relates to a method for producing an electromagnetically actuatable suction valve (1).

A polyacetal resin composition capable of minimizing degradation when a molded body thereof comes into contact with an acidic cleaner. The polyacetal resin composition contains with respect to (A) 100 parts by mass of a polyacetal copolymer in which the amount of a hemiformal end group is 0.8 mmol/kg or less, (B) more than 1.0 parts by mass and at most 5.0 parts by mass of a hindered phenol-based antioxidant, and (C) more than 4.0 parts by mass and at most 30 parts by mass of magnesium oxide.

A protector protects a high-pressure fuel pump for an internal combustion engine. A metal collar is insert-molded into a plate-shaped fiber reinforced plastic portion made of a fiber reinforced plastic of the protector. An outer circumferential surface of the collar includes an uneven portion and a smooth surface. The uneven portion includes recesses and projections arranged alternately in a thickness direction of the fiber reinforced plastic portion. The smooth portion includes a smooth surface parallel to the thickness direction of the fiber reinforced plastic portion. The uneven portion and the smooth portion are arranged in the thickness direction on the outer circumferential surface of the collar.

Disclosed herein are a novel polyacetal resin composition and a vehicle fuel pump module made of the same with excellent acid resistance.