Abstract: A resin gear comprises a rim in an outer peripheral part of a plate, teeth provided on an outer periphery of the rim, a boss provided in a central part of the plate, and a circular rib between the boss and the rim. The resin gear is manufacturable by injection molding that a molten material is injected into a cavity through a plurality of gates arranged at almost equally spaced intervals circumferentially on a forming portion for the circular rib in a direction perpendicular to a side of the plate. The resin gear includes a plurality of inner thin-wall portions on the plate between the circular rib and the boss and a plurality of outer thin-wall portions on the plate between the circular rib and the rim, each of the inner thin-wall portions and the outer thin-wall portions being symmetrically shaped with respect to the radial line passing through each gate corresponding point.

Abstract: A flow control valve includes a seal member disposed within an annular space. The annular space is defined between at least one of bearing fitting portions of a flow path defining member and a corresponding valve shaft portion of a valve member opposing to each other in a radial direction with respect to an axis of the valve shaft portion and between an end face of a corresponding bearing and an end face of a valve body portion opposing to each other in a direction of the axis. The seal member can seal between the bearing fitting portion and the corresponding valve shaft portion with respect to the radial direction and can also seal between the corresponding bearing and the valve body portion with respect to the axial direction.

Abstract: A resin gear comprises a rim in an outer peripheral part of a plate, teeth provided on an outer periphery of the rim, a boss provided in a central part of the plate, and a circular rib between the boss and the rim. The resin gear is manufacturable by injection molding that a molten material is injected into a cavity through a plurality of gates arranged at almost equally spaced intervals circumferentially on a forming portion for the circular rib in a direction perpendicular to a side of the plate. The resin gear includes a plurality of inner thin-wall portions on the plate between the circular rib and the boss and a plurality of outer thin-wall portions on the plate between the circular rib and the rim, each of the inner thin-wall portions and the outer thin-wall portions being symmetrically shaped with respect to the radial line passing through each gate corresponding point.

Abstract: An intake control device includes a throttle valve and a throttle body. The throttle valve rotates to control intake air. The throttle body includes a cylindrical throttle bore portion defining a circular throttle bore that accommodates the throttle valve. The throttle body includes a cylindrical motor housing portion arranged on the radially outer side of the throttle bore portion. The motor housing portion defines a motor accommodating hole, in which a motor is accommodated to rotate the throttle valve. The throttle body includes a flange portion that extends from one axial end of the throttle bore portion to the radially outer side thereof. The throttle body is connected to the engine via the flange portion. The throttle body is formed of resin integrally with a housing connecting rib that connects the flange portion directly with the motor housing portion.

Abstract: An intake air control device, which is mounted to a fixed member, includes a throttle body and a throttle valve. The throttle body defines an intake air passage. The throttle valve is rotatably supported in the throttle body to control an amount of intake air flowing through the intake air passage. The throttle body includes a cylindrical portion, a plurality of fixed portions, and a strain absorbing portion. The cylindrical portion defines the intake air passage that accommodates the throttle valve. The plurality of fixed portions are connected to the fixed member. The strain absorbing portion connects the cylindrical portion with the plurality of fixed portions to absorb displacement arising in the plurality of fixed portions. The strain absorbing portion is a deformable connecting arm that connects to the cylindrical portion in a location, which is apart from a radially inner periphery of the plurality of fixed portions.

Abstract: A molding dies have a first shaft holding portion and a second shaft holding portion. The first shaft holding portion supports an outer surface of a metal shaft which is exposed between an axial end surface of the throttle valve and a first collar molded in the throttle body. The second shaft holding portion supports an outer surface of the metal shaft which is exposed between the other axial end surface and a second collar molded in the throttle body. The first and the second collar have a first and second shaft holes into which the metal shaft is inserted. The first and the second holding portions restrict a flowing of melted resin into the first and the second shaft holes.

Abstract: A throttle body of an electrically controlled throttle apparatus is constructed with a bore wall part, a motor housing part receiving a heavy component such as a motor and a connecting member that connects the bore wall part and the motor housing part with each other. The bore wall part has a cylindrical inner periphery for rotatably receiving a circular-shaped throttle valve. The connecting member is constructed with plural plate-shaped ribs. Thus, the connecting member can be rigid without becoming a thick member. Therefore, the connecting member can be restricted from contracting in its molding process, so that circularity of the cylindrical inner periphery of the bore wall part can be maintained. Thus, the cylindrical inner periphery of the bore wall part can rotatably receive the circular-shaped throttle valve without arising interference against each other, and airtightness of the throttle valve can be maintained, when the throttle valve is in the full close position.

Abstract: An intake control device for an engine includes a throttle body that defines a throttle bore, which is substantially circular-shaped in cross section, through which intake air flows. A throttle valve is rotatably assembled in the throttle bore of the throttle body. The throttle valve rotates integrally with a shaft. One axial end of the shaft is connected to a rotary driver, so that the rotation angle of the throttle valve is changed via the shaft. The rotary driver defines a fitted hole, to which the one axial end of the shaft is clearance fitted. The rotary driver defines a fitting recess dented radially outward from the hole wall surface of the fitted hole. The one axial end of the shaft includes a coupling that is crimped and fixed to the rotary driver in the state of being fitted to the fitted hole.

Abstract: A throttle shaft, first and second bearings, are inserted and formed in a bore wall part of a throttle body, when the throttle body is formed in the same dies. That is, when the throttle body is formed in a predetermined shape, the throttle shaft, the first and second bearings, are received in the bore wall part of the throttle body. First and second step portions, are formed in the throttle shaft, and axially inserted by first and second supporting portions, respectively formed in the first and second bearings, from both axially ends of the throttle shaft. Therefore, the throttle shaft can be restricted from moving axially, without additional thrust restricting means, such as an E-ring and a C-ring.

Abstract: A resinous throttle body has a bore wall part having a double pipe structure constructed with a bore inner pipe and a bore outer pipe that are connected with each other via an annular connecting part. The annular connecting part has axial board thickness set to be less than the minimum radial thickness of a portion of the bore inner pipe and a portion of the bore outer pipe that are located around the annular connecting part. Therefore, the annular connecting part can be formed to be in a thin-walled radially elongated plate shape. The annular connecting part has a radially cross-sectional length larger than its axial board thickness, so that rigidity and strength of the annular connecting part is decreased. Therefore, contraction of the bore outer pipe occurred in its molding process does not largely affect the bore inner pipe, so that a cylindrical-shaped inner periphery of the bore inner wall, which rotatably receives a disc-shaped throttle valve, can be restricted from being deformed.

Abstract: An intake control device for an engine includes a throttle body that defines a throttle bore, which is substantially circular-shaped in cross section, through which intake air flows. A throttle valve is rotatably assembled in the throttle bore of the throttle body. The throttle valve rotates integrally with a shaft. One axial end of the shaft is connected to a rotary driver, so that the rotation angle of the throttle valve is changed via the shaft. The rotary driver defines a fitted hole, to which the one axial end of the shaft is clearance fitted. The rotary driver defines a fitting recess dented radially outward from the hole wall surface of the fitted hole. The one axial end of the shaft includes a coupling that is crimped and fixed to the rotary driver in the state of being fitted to the fitted hole.

Abstract: An intake control device includes a throttle valve and a throttle body. The throttle valve rotates to control intake air. The throttle body includes a cylindrical throttle bore portion defining a circular throttle bore that accommodates the throttle valve. The throttle body includes a cylindrical motor housing portion arranged on the radially outer side of the throttle bore portion. The motor housing portion defines a motor accommodating hole, in which a motor is accommodated to rotate the throttle valve. The throttle body includes a flange portion that extends from one axial end of the throttle bore portion to the radially outer side thereof. The throttle body is connected to the engine via the flange portion. The throttle body is formed of resin integrally with a housing connecting rib that connects the flange portion directly with the motor housing portion.

Abstract: A throttle valve is rotatably disposed in an air passage formed in a throttle body. An amount of air supplied to an internal combustion engine is controlled by rotating the throttle valve. The throttle valve connected to a throttle shaft and the throttle body are formed at the same time by injecting molten resin into a molding die, in which a pair of bearing holders and the throttle shaft are set at predetermined positions. After the throttle body is taken out of the molding die, a pair of bearings are press-fitted into the bearing holders so that the throttle shaft is rotatably supported in the throttle body by the bearings. In this manner, deformation of the bearings in the molding process is avoided, and smooth rotation of the throttle valve is secured.

Abstract: Vibration insulators made of heatproof elastomer are integrally molded with an engine joint section of the heatproof resinous throttle body and a motor holder. Thus, engine vibration transferred from an engine intake manifold to the throttle body and the motor can be absorbed by the vibration insulators. Therefore, without increase of components and reduction of assembling workability, the vibration can be suppressed.

Abstract: An intake air control device, which is mounted to a fixed member, includes a throttle body and a throttle valve. The throttle body defines an intake air passage. The throttle valve is rotatably supported in the throttle body to control an amount of intake air flowing through the intake air passage. The throttle body includes a cylindrical portion, a plurality of fixed portions, and a strain absorbing portion. The cylindrical portion defines the intake air passage that accommodates the throttle valve. The plurality of fixed portions are connected to the fixed member. The strain absorbing portion connects the cylindrical portion with the plurality of fixed portions to absorb displacement arising in the plurality of fixed portions. The strain absorbing portion is a deformable connecting arm that connects to the cylindrical portion in a location, which is apart from a radially inner periphery of the plurality of fixed portions.

Abstract: A throttle device for an internal combustion engine designed to absorb variations in dimensions of components by centering a closed-bottom tube of an integral plug-type slide bearing with a plastic shaft part of a throttle shaft, inserting a tube of the slide bearing in a ring-shaped clearance formed between an inner circumference of a first shaft insertion hole of a first bearing support of a throttle body and outer circumference of a first sliding part of the plastic shaft, then fixing by welding a ring-shaped end face of a flange of the slide bearing to a ring-shaped end face of the first bearing support using a welding method such as laser welding.

Abstract: A molding dies have a first shaft holding portion and a second shaft holding portion. The first shaft holding portion supports an outer surface of a metal shaft which is exposed between an axial end surface of the throttle valve and a first collar molded in the throttle body. The second shaft holding portion supports an outer surface of the metal shaft which is exposed between the other axial end surface and a second collar molded in the throttle body. The first and the second collar have a first and second shaft holes into which the metal shaft is inserted. The first and the second holding portions restrict a flowing of melted resin into the first and the second shaft holes.

Abstract: A throttle shaft, first and second bearings, are inserted and formed in a bore wall part of a throttle body, when the throttle body is formed in the same dies. That is, when the throttle body is formed in a predetermined shape, the throttle shaft, the first and second bearings, are received in the bore wall part of the throttle body. First and second step portions, are formed in the throttle shaft, and axially inserted by first and second supporting portions, respectively formed in the first and second bearings, from both axially ends of the throttle shaft. Therefore, the throttle shaft can be restricted from moving axially, without additional thrust restricting means, such as an E-ring and a C-ring.

Abstract: A throttle body of an electrically controlled throttle apparatus is constructed with a bore wall part, a motor housing part receiving a heavy component such as a motor and a connecting member that connects the bore wall part and the motor housing part with each other. The bore wall part has a cylindrical inner periphery for rotatably receiving a circular-shaped throttle valve. The connecting member is constructed with plural plate-shaped ribs. Thus, the connecting member can be rigid without becoming a thick member. Therefore, the connecting member can be restricted from contracting in its molding process, so that circularity of the cylindrical inner periphery of the bore wall part can be maintained. Thus, the cylindrical inner periphery of the bore wall part can rotatably receive the circular-shaped throttle valve without arising interference against each other, and airtightness of the throttle valve can be maintained, when the throttle valve is in the full close position.

Abstract: A resinous throttle body has a bore wall part having a double pipe structure constructed with a bore inner pipe and a bore outer pipe that are connected with each other via an annular connecting part. The annular connecting part has axial board thickness set to be less than the minimum radial thickness of a portion of the bore inner pipe and a portion of the bore outer pipe that are located around the annular connecting part. Therefore, the annular connecting part can be formed to be in a thin-walled radially elongated plate shape. The annular connecting part has a radially cross-sectional length larger than its axial board thickness, so that rigidity and strength of the annular connecting part is decreased. Therefore, contraction of the bore outer pipe occurred in its molding process does not largely affect the bore inner pipe, so that a cylindrical-shaped inner periphery of the bore inner wall, which rotatably receives a disc-shaped throttle valve, can be restricted from being deformed.