Abstract: A resonator is arranged in an intake system including a pipe section for partitioning an intake port from an intake passage that communicates the intake port with a combustion chamber of an engine, the resonator including: a branch pipe having one end branching to the pipe section and the other end closed so that a silencing chamber is defined therein; and at least one partition wall for partitioning the silencing chamber into at least one pneumatic spring chamber, the partition wall having a natural frequency lower than the frequency of silencing target sound of intake noise propagated from the intake passage.

Abstract: A duct main body is formed into a hollow tubular shape having in an interior thereof an intake passageway for introducing outside air into an internal combustion engine by connecting integrally a plurality of divided bodies such as a first divided body and a second divided body which are formed of a thermoplastic resin and has in a duct wall of the second divided body an opening which establishes a communication between the inside and outside of the intake passageway. An air-permeable member is insert molded in the second divided body in such a manner as to cover the opening. The air-permeable member has on an outer edge thereof a joining portion which is impregnated with the thermoplastic resin.

Abstract: A raised distal end portion of a strut portion is in a non-joined state to a back side of an upper duct wall portion and is made up of a spherical abutting and sliding portion which can be brought into abutment with the back side by virtue of point contact and which is allowed to slide relative to the back side. When a downward pressure is exerted on to the spherical abutting and sliding portion from the upper duct wall portion, the spherical abutting and sliding portion is caused to slide relative to the back side and a root portion of the strut portion is deformed at the same time, whereby the strut portion is allowed to incline and fall obliquely downwards.

Abstract: A duct main body is formed into a hollow tubular shape having in an interior thereof an intake passageway for introducing outside air into an internal combustion engine by connecting integrally a plurality of divided bodies such as a first divided body and a second divided body which are formed of a thermoplastic resin and has in a duct wall of the second divided body an opening which establishes a communication between the inside and outside of the intake passageway. An air-permeable member is insert molded in the second divided body in such a manner as to cover the opening. The air-permeable member has on an outer edge thereof a joining portion which is impregnated with the thermoplastic resin.

Abstract: A grommet provided with an annular engaging groove serving as an engaging means is fixed to a distal end portion of a column portion. A mating engaging means, which has a through hole serving as an escape opening and is detachable with the annular engaging groove by an opening peripheral edge portion defining this through hole, is formed in a lower duct wall portion at a position corresponding to the column portion. If an external load of a predetermined value or more is applied to an upper duct wall portion, and a state of engagement between the annular engaging groove and the opening peripheral edge portion is thereby canceled, the column portion enters the through hole without being fractured or damaged, and the upper duct wall portion is deformed toward the lower duct wall portion side.

Abstract: A raised distal end portion of a strut portion is in a non-joined state to a back side of an upper duct wall portion and is made up of a spherical abutting and sliding portion which can be brought into abutment with the back side by virtue of point contact and which is allowed to slide relative to the back side. When a downward pressure is exerted on to the spherical abutting and sliding portion from the upper duct wall portion, the spherical abutting and sliding portion is caused to slide relative to the back side and a root portion of the strut portion is deformed at the same time, whereby the strut portion is allowed to incline and fall obliquely downwards.

Abstract: A resonator is arranged in an intake system including a pipe section for partitioning an intake port from an intake passage that communicates the intake port with a combustion chamber of an engine, the resonator including: a branch pipe having one end branching to the pipe section and the other end closed so that a silencing chamber is defined therein; and at least one partition wall for partitioning the silencing chamber into at least one pneumatic spring chamber, the partition wall having a natural frequency lower than the frequency of silencing target sound of intake noise propagated from the intake passage.

Abstract: The manufacturing method for the air intake apparatus has a holding-portion forming step, a temporarily fixing step, and a joining step. In the holding-portion forming step, a holding portion is formed. In the temporarily fixing step, the porous member is held by the holding portion. In the joining step, the holding portion and the porous member are joined together. Thus, an air intake apparatus, in which the opening is reliably covered with the porous member, can be manufactured. In the air intake apparatus manufactured by this manufacturing method, a peripheral portion of the porous member is doubly sealed with the holding portion that is an outer edge part of the opening. Consequently, the opening is reliably covered with the porous member, so that intake noise is reliably reduced.

Abstract: The manufacturing method for the air intake apparatus has a holding-portion forming step, a temporarily fixing step, and a joining step. In the holding-portion forming step, a holding portion is formed. In the temporarily fixing step, the porous member is held by the holding portion. In the joining step, the holding portion and the porous member are joined together. Thus, an air intake apparatus, in which the opening is reliably covered with the porous member, can be manufactured. In the air intake apparatus manufactured by this manufacturing method, a peripheral portion of the porous member is doubly sealed with the holding portion that is an outer edge part of the opening. Consequently, the opening is reliably covered with the porous member, so that intake noise is reliably reduced.