Abstract: An intake manifold includes: a surge tank, die-molded to temporarily store intake air; and branch pipes, in communication with the surge tank. The surge tank includes, on an outer wall thereof, a flange part and a reinforcement rib, a sensor unit configured to detect an intake air state quantity being installed to the a part. The flange part includes: a fitting hole, having an axis as a center to be fit with a detection part of the sensor unit; and boss parts, provided on a periphery of the fitting hole, and the flange part is formed to be rotationally symmetric with the axis as a center. The reinforcement rib includes a limitation piece interfering with a portion of the sensor unit to limit assembling at a time when the sensor unit is assembled erroneously for being deviated from a normal orientation.

Abstract: An intake manifold includes: a surge tank, die-molded to temporarily store intake air; and branch pipes, in communication with the surge tank. The surge tank includes, on an outer wall thereof, a flange part and a reinforcement rib, a sensor unit configured to detect an intake air state quantity being installed to the a part. The flange part includes: a fitting hole, having an axis as a center to be fit with a detection part of the sensor unit; and boss parts, provided on a periphery of the fitting hole, and the flange part is formed to be rotationally symmetric with the axis as a center. The reinforcement rib includes a limitation piece interfering with a portion of the sensor unit to limit assembling at a time when the sensor unit is assembled erroneously for being deviated from a normal orientation.

Abstract: An intake manifold 2 suitable for an engine includes: a surge tank 100, die-molded to temporarily store intake air; and a plurality of branch pipes 211, 212, 213, 311, 312, 313, in communication with the surge tank. The surge tank 100 includes: a boss part 111, having a cylindrical shape; and boss reinforcement ribs 114, extending in a direction toward a center S of the boss part and connected with the boss part, the boss part and the boss reinforcement ribs being integrally formed on an outer wall of the surge tank.

Abstract: An intake manifold which can ensure a pressure resistance strength, a mechanical strength, and the like and also reduce a passage resistance and an outboard motor which can be made smaller and thinner in a width direction. A resinous intake manifold made of a resin and configured to be applied to an engine of an outboard motor includes: a surge tank which forms a flat contour and includes an intake inlet; and a plurality of branch pipes which defines intake passages communicating with an internal space of the surge tank, wherein a contour wall of the surge tank includes a plurality of ridge portions which protrudes toward the internal space and is oriented toward the intake passage side.

Abstract: An intake manifold which can ensure a pressure resistance strength, a mechanical strength, and the like and also reduce a passage resistance and an outboard motor which can be made smaller and thinner in a width direction. A resinous intake manifold made of a resin and configured to be applied to an engine of an outboard motor includes: a surge tank which forms a flat contour and includes an intake inlet; and a plurality of branch pipes which defines intake passages communicating with an internal space of the surge tank, wherein a contour wall of the surge tank includes a plurality of ridge portions which protrudes toward the internal space and is oriented toward the intake passage side.

Abstract: To provide a compact intake manifold which can easily and reliably hold the flame arrester (25) to the base member, the base member (21) having the flame arrester (25) incorporated therein has the recessed body portion (31) and the annular fitting holding portion (32) for fitting the flame arrester (25) in the axial direction. The fitting holding portion (32) includes an abutment surface (32a) and a fitting inner wall peripheral surface (32b). The flame arrester (25) includes a flame suppressing structure (26), an outer cylinder body (27) surrounding the flame suppression structure (26), and an elastic holder member (51) which covers the outer peripheral surface and both end faces of the outer cylindrical body (27). The elastic holder member (51) has an outer peripheral fitting portion (52) fitted to the fitting holding portion (32) while being held in close contact with the outer cylindrical body (27).

Abstract: To provide an intake manifold which can reliably prevent the step from being formed in the inner wall surface of the intake passage (15) while having provided therein the fitting holding portion (32) for fitting and holding the flame arrester (25) in the axial direction, the intake manifold (10) includes a base member (21), a cover member (22) and a flame arrester (25) having a flame suppression structure. Between the flame arrester (25) and the radical stepped surface (31b) of the recessed body portion (31) is provided a retaining rectifying member (23) that prevents the flame arrester (25) from coming off with respect to the fitting holding portion (32) and forms a third inner peripheral surface (23a) continuous without a step from an opening portion on the other end side (25b) of the flame arrester (25) to the base side second inner wall surface (31c).

Abstract: To provide a compact intake manifold which can easily and reliably hold the flame arrester (25) to the base member, the base member (21) having the flame arrester (25) incorporated therein has the recessed body portion (31) and the annular fitting holding portion (32) for fitting the flame arrester (25) in the axial direction. The fitting holding portion (32) includes an abutment surface (32a) and a fitting inner wall peripheral surface (32b). The flame arrester (25) includes a flame suppressing structure (26), an outer cylinder body (27) surrounding the flame suppression structure (26), and an elastic holder member (51) which covers the outer peripheral surface and both end faces of the outer cylindrical body (27). The elastic holder member (51) has an outer peripheral fitting portion (52) fitted to the fitting holding portion (32) while being held in close contact with the outer cylindrical body (27).

Abstract: To provide an intake manifold which can reliably prevent the step from being formed in the inner wall surface of the intake passage (15) while having provided therein the fitting holding portion (32) for fitting and holding the flame arrester (25) in the axial direction, the intake manifold (10) includes a base member (21), a cover member (22) and a flame arrester (25) having a flame suppression structure. Between the flame arrester (25) and the radical stepped surface (31b) of the recessed body portion (31) is provided a retaining rectifying member (23) that prevents the flame arrester (25) from coming off with respect to the fitting holding portion (32) and forms a third inner peripheral surface (23a) continuous without a step from an opening portion on the other end side (25b) of the flame arrester (25) to the base side second inner wall surface (31c).