A resonator insert (14) is provided for coaxial and sectionally radially spaced insertion in an intake pipe of a turbocharger (10). The resonator insert (14) has a tube section (141) with a wall having circumferentially extending, axially adjacent through-slots (142). The wall of the tube section (141) carries at least one radially outwardly directed, axially extending lamella (144) crossing the through-slots (142). A turbocharger with an upstream resonator also is provided.

This outboard machine has: a V-type engine (engine) in which a plurality of cylinders are arranged in a V-shape when viewed in a plan view; and a cover that covers the engine. The engine has a plurality of intake ports that form pairs in a V-shape inside the plurality of cylinders in a plan view and a concave space is formed between the plurality of intake ports. The cover has therein an intake path that guides air to the intake port, and is also provided with, at a position that is adjacent to the intake path and enters the concave space, a silencer that attenuates the sound during intake.

This outboard machine has: a V-type engine (engine) in which a plurality of cylinders are arranged in a V-shape when viewed in a plan view; and a cover that covers the engine. The engine has a plurality of intake ports that form pairs in a V-shape inside the plurality of cylinders in a plan view and a concave space is formed between the plurality of intake ports. The cover has therein an intake path that guides air to the intake port, and is also provided with, at a position that is adjacent to the intake path and enters the concave space, a silencer that attenuates the sound during intake.

The invention relates to a method of operating a four stroke internal combustion engine system (1), the engine system (1) comprising:—a four stroke internal combustion engine (2) provided with an intake duct (5),—a turbo compressor (6″) arranged to compress intake flow in the intake duct (5), and—a displacement machine (7) provided in the intake duct (5) downstream the turbo compressor (6″), wherein the displacement machine (7) is arranged to displace intake flow from an inlet to an outlet thereof. The method comprises the step of: operating the displacement machine (7) in a first mode where a pressure ratio (PR) given by a pressure at the outlet of the displacement machine (7) divided by a pressure at the inlet of the displacement machine (7) is substantially equal to 1. The invention also relates to a four stroke internal combustion engine system arranged to be operated by the above method.

A negative pressure control valve (44) is disposed in a part of an intake passage (12) upstream of a confluence (30) of an EGR passage (27) and the intake passage (12). When in an EGR region (Regr) where an EGR gas is recirculated to the intake passage (12) through the EGR passage (27), the negative pressure control valve (44) is controlled in a manner to ensure a differential pressure between an exhaust passage (13) and the intake passage (12). When in an operation region (R2) lower in load than the EGR region (Regr), the negative pressure control valve (44) is controlled in a closing direction so as to suppress occurrence of noise.

A polyamide resin composition contains a polyamide resin and an inorganic filler. 90 mass % or more of polyamide 66 is contained relative to 100 mass % of the polyamide resin. The inorganic filler content is ≥30 mass % relative to 100 mass % of the composition. The composition has a solidifying point of ≥210° C. The composition has a spiral flow value of ≥60 cm when the inorganic filler content is ≥30 mass % and <40 mass %, ≥40 cm when the content is ≥40 mass % and ≤50 mass %, and ≥20 cm when the content is >50 mass % and ≤70 mass %. The composition has a strain of ≤3.8% in a 1000-hour tensile creep test under 120° C. and 60 MPa. The composition has a formic acid relative viscosity (VR) of 30<VR<40.

A polyamide resin composition contains a polyamide resin and an inorganic filler. 90 mass % or more of polyamide 66 is contained relative to 100 mass % of the polyamide resin. The inorganic filler content is ≥30 mass % relative to 100 mass % of the composition. The composition has a solidifying point of ≥210° C. The composition has a spiral flow value of ≥60 cm when the inorganic filler content is ≥30 mass % and <40 mass %, ≥40 cm when the content is ≥40 mass % and ≤50 mass %, and ≥20 cm when the content is >50 mass % and ≤70 mass %. The composition has a strain of ≤3.8% in a 1000-hour tensile creep test under 120° C. and 60 MPa. The composition has a formic acid relative viscosity (VR) of 30<VR<40.

The invention relates to a fluid pipe arrangement (100), in particular for a charged air duct of an internal combustion engine, comprising a housing (10) having a longitudinal extension (L). The housing (10) includes a first fluid duct (20) having a first fluid inlet (22) and a first fluid outlet (24) for a first fluid and at least one second fluid duct (30) having a second fluid inlet (32) and a second fluid outlet (34) for a second fluid. Thermal insulation means (40) are provided between at least a portion (38) of the second fluid duct (30) and at least a portion (28) the first fluid duct (20).

Methods and systems are provided for enhancing and delivering engine sounds to a vehicle cabin based on a selected mode. In one example, a method may include adjusting openings of one or more valves fluidically coupling one or more corresponding engine regions to a sound tube of a sound enhancing system based on the selected mode. Throttle opening may also be adjusted to compensate for air routed from the engine regions to the sound tube instead of flowing to the engine cylinders.

A ventilation component includes a circumferential wall. At least a part of the circumferential wall is formed by the wall portion, which includes the inner layer and the outer layer. The inner layer contains fibers and has permeability, and the outer layer is provided on the radially outer side of the inner layer and has elasticity. The wall portion forms a vibration system including the inner layer as a mass portion and the outer layer as a spring portion. The vibration system has a partially varying natural frequency.