Abstract: The present invention attains downsizing of a permanent magnet with a simple structure to reduce a manufacturing cost thereof. Provided is a rotation angle detection device, including: a cylindrical magnetic circuit mounted to a shaft; and non-contact sensors provided in an inner void of the magnetic circuit, in which the magnetic circuit is composed of a first yoke and a second yoke formed of a magnetic material and having a pair of flat portions parallel and opposed to each other, and a pair of permanent magnets whose magnetic poles are aligned in the same direction so that magnetic fields whose magnetic fluxes are parallel to each other are generated in the void between the flat portions, and the non-contact sensor detects a rotation angle of the shaft by detecting a change in the direction of the magnetic fluxes.

Abstract: A non-contact type rotational angle detection apparatus can reduce the number of parts required, improve productivity, and prevent a relative displacement between a permanent magnet and a yoke. An insert molded body is fixedly secured to a shaft and is composed of a permanent magnet and a yoke formed integrally with each other by insert molding of a resin. A non-contact sensor is disposed in an inner space formed in the insert molded body. The non-contact sensor detects a rotation angle of the shaft by detecting an azimuth of magnetic flux lines generated by the permanent magnet. The cylindrical yoke is fixedly secured by shrinkage fitting to the cylindrical permanent magnet disposed at an inner side thereof. An engagement margin between the permanent magnet and the yoke is set equal to or greater than a value which restrains a relative displacement between the permanent magnet and the yoke.

Abstract: A rotation angle detecting apparatus includes: a first permanent magnet; a second permanent magnet disposed so as to face the first permanent magnet, the second permanent magnet rotating together with a shaft; an arc-shaped first magnetic member and second magnetic member fixed to the first permanent magnet and the second permanent magnet; and a magnetic resistor disposed in an air gap formed between the first magnetic member and the second magnetic member so as to be axially aligned with the shaft, the first magnetic member and the second magnetic member each including: a projecting portion pointed at the magnetic resistor; and a wall portion surrounding the magnetic resistor so as to prevent influence from external magnetic fields.

Abstract: A rotation angle detection apparatus is capable of preventing an eddy current and radio wave noise from being transmitted from outside to a yoke and a permanent magnet through a metal plate, and thence to a non-contact sensor through radiation as it is. The apparatus includes a yoke, a permanent magnet that is arranged on an inner wall surface with magnetic flux flowing from its N pole to its S pole through an inner space thereof, a metal plate formed integral with the yoke and the permanent magnet through a resin by insert molding, and a non-contact sensor arranged in the inner space of the permanent magnet. Between the metal plate and the individual end faces of the yoke and the permanent magnet, there is interposed a high impedance member that prevents radio wave noise from flowing from the metal plate to the yoke and the permanent magnet.

Abstract: The present invention attains downsizing of a permanent magnet with a simple structure to reduce a manufacturing cost thereof. Provided is a rotation angle detection device, including: a cylindrical magnetic circuit mounted to a shaft; and non-contact sensors provided in an inner void of the magnetic circuit, in which the magnetic circuit is composed of a first yoke and a second yoke formed of a magnetic material and having a pair of flat portions parallel and opposed to each other, and a pair of permanent magnets whose magnetic poles are aligned in the same direction so that magnetic fields whose magnetic fluxes are parallel to each other are generated in the void between the flat portions, and the non-contact sensor detects a rotation angle of the shaft by detecting a change in the direction of the magnetic fluxes.

Abstract: An intake-air control device for an internal combustion engine in which a sensor member can be positioned further accurately is provided. A throttle position sensor includes magnetic field generating means and a magnetic field detecting assembly. The magnetic field detecting assembly includes a plurality of terminal leads, a resin holder secured on the plurality of terminal leads, a sensor member generating a sensor output, and a resin mold body including the plurality of terminal leads, the holder, and the sensor member insert-molded. The resin holder includes a supporting surface which is located on a plane intersecting substantially perpendicularly to an axial line of a throttle shaft, and the sensor member includes a resin mold coat having first and second main surfaces opposing substantially in parallel to each other. The sensor member is held in the resin mold body with the first main surface of the resin mold coat in contact with the supporting surface.

Abstract: A rotation angle detecting apparatus includes: a first permanent magnet; a second permanent magnet disposed so as to face the first permanent magnet, the second permanent magnet rotating together with a shaft; an arc-shaped first magnetic member and second magnetic member fixed to the first permanent magnet and the second permanent magnet; and a magnetic resistor disposed in an air gap formed between the first magnetic member and the second magnetic member so as to be axially aligned with the shaft, the first magnetic member and the second magnetic member each including: a projecting portion pointed at the magnetic resistor; and a wall portion surrounding the magnetic resistor so as to prevent influence from external magnetic fields.

Abstract: An intake-air control device for an internal combustion engine in which a sensor member can be positioned further accurately is provided. A throttle position sensor includes magnetic field generating means and a magnetic field detecting assembly. The magnetic field detecting assembly includes a plurality of terminal leads, a resin holder secured on the plurality of terminal leads, a sensor member generating a sensor output, and a resin mold body including the plurality of terminal leads, the holder, and the sensor member insert-molded. The resin holder includes a supporting surface which is located on a plane intersecting substantially perpendicularly to an axial line of a throttle shaft, and the sensor member includes a resin mold coat having first and second main surfaces opposing substantially in parallel to each other. The sensor member is held in the resin mold body with the first main surface of the resin mold coat in contact with the supporting surface.

Abstract: An intake air quantity controlling device for an internal combustion engine that includes a shaft, a throttle valve, a final spur gear, a drive motor, a full closure stopper, a full opening stopper, and a collision portion. The shaft is rotatably provided across an intake passage. The throttle valve is fixed to the shaft. The final spur gear is fixed to an end portion of the shaft. The drive motor applies a rotational force to the final spur gear. A full closure stopper determines a full closure position of the throttle valve, and full opening stopper determines a full opening position of the throttle valve. The final spur gear is provided with the collision portion, which collides with the full closure stopper and the full opening stopper to stop rotation of the final spur gear.

Abstract: An intake air control apparatus for an engine is capable of suppressing the influence of external magnetic flux from outside thereby to prevent a variation in an output of a rotational angle detection sensor due to the external magnetic flux. A permanent magnet is provided on an end portion of a shaft. A rotational angle detection sensor is disposed in a spaced parallel relation with respect to the permanent magnet, and has a magnetoresistive element for detecting a change in direction of a magnetic flux of the permanent magnet thereby to detect a rotational angle of a throttle valve. A bypass member is disposed to enclose the rotational angle detection sensor with its side near the permanent magnet apertured to form an opening surface, the bypass member being made of a magnetic material which is adapted to form a bypass path for the magnetic flux from the permanent magnet.

Abstract: A rotation angle detection device is simple in structure and is capable of reducing the size of a permanent magnet. The permanent magnet is fixedly secured to a rotating member. A first guide member is attached at one end face to an S pole side of the permanent magnet. A second guide member is attached at one end face to an N pole side of the permanent magnet, and has its tip end disposed in opposition to a tip end of the first guide member. A magnetoresistive member is disposed in a space between the tip ends of the first and second guide members, the magnetoresistive member being fixedly attached to a non-rotating member. An angle of rotation of the rotating member is detected by detecting a change of the azimuth of magnetic flux, which is generated by the permanent magnet in the space, by means of the magnetoresistive member.

Abstract: A rotation angle detection device is simple in structure and is capable of reducing the size of a permanent magnet. The permanent magnet is fixedly secured to a rotating member. A first guide member is attached at one end face to an S pole side of the permanent magnet. A second guide member is attached at one end face to an N pole side of the permanent magnet, and has its tip end disposed in opposition to a tip end of the first guide member. A magnetoresistive member is disposed in a space between the tip ends of the first and second guide members, the magnetoresistive member being fixedly attached to a non-rotating member. An angle of rotation of the rotating member is detected by detecting a change of the azimuth of magnetic flux, which is generated by the permanent magnet in the space, by means of the magnetoresistive member.

Abstract: An intake air amount control apparatus for an engine is capable of stabilizing the controllability of a valve (10) as well as reducing the number of component parts required. A coil spring (11) includes a first spring portion (11a) having a first end portion (12), a second spring portion (11b) having a second end portion (13), a joint portion (19) that connects the first spring portion (11a) and the second spring portion (11b) with each other. The first end portion (12) of the first spring portion (11a) and the second end portion (13) of the second spring portion (11b) are attached to a body (9) through a movable member (14), and the joint portion (19) is attached to a final spur gear (4).

Abstract: An air control apparatus for an engine can relax the tolerance of positional accuracy in the mounting of a rotational angle detection sensor. The intake air control apparatus includes: a shaft (6); a throttle valve (7) fixedly secured to the shaft (6) for adjusting the degree of opening in an intake passage through a rotational angle thereof; a permanent magnet (12) provided on an end portion of the shaft (6) with its N pole and S pole being positioned in a diametral direction thereof; and a rotational angle detection sensor (14) having a magnetoresistive element disposed in a spaced parallel relation with respect to the permanent magnet (12) for detecting a change in the azimuth of magnetic flux of the permanent magnet (12) thereby to sense a rotational angle of the throttle valve (7).

Abstract: In a non-contact type rotation-angle sensing device, a rotation angle sensor (9) having magnetoresistance elements detects a rotation angle of an object to be measured. The object is rotatable round a rotary shaft (2) with respect to the rotation angle sensor (9) and includes a permanent magnet (5, 6). The permanent magnet (5, 6) is disposed symmetrically about said rotary shaft (2) of said object, and a magnetic element (7, 8) is disposed on said object between said permanent magnet (5, 6) and the magnetoresistance elements. In the non-contact type rotation-angle sensing device of above constitution according to the invention, linearity is secured by reducing magnetic hysteresis of the sensor output with respect to the rotation angle, thus a small-sized permanent magnet and reduction in cost being achieved.

Abstract: An intake air control apparatus for an engine is capable of suppressing the influence of external magnetic flux from outside thereby to prevent a variation in an output of a rotational angle detection sensor due to the external magnetic flux. A permanent magnet is provided on an end portion of a shaft. A rotational angle detection sensor is disposed in a spaced parallel relation with respect to the permanent magnet, and has a magnetoresistive element for detecting a change in direction of a magnetic flux of the permanent magnet thereby to detect a rotational angle of a throttle valve. A bypass member is disposed to enclose the rotational angle detection sensor with its side near the permanent magnet apertured to form an opening surface, the bypass member being made of a magnetic material which is adapted to form a bypass path for the magnetic flux from the permanent magnet.

Abstract: An intake air control apparatus for an engine can relax the tolerance of positional accuracy in the mounting of a rotational angle detection sensor. The intake air control apparatus includes: a shaft (6); a throttle valve (7) fixedly secured to the shaft (6) for adjusting the degree of opening in an intake passage through a rotational angle thereof; a permanent magnet (12) provided on an end portion of the shaft (6) with its N pole and S pole being positioned in a diametral direction thereof; and a rotational angle detection sensor (14) having a magnetoresistive element disposed in a spaced parallel relation with respect to the permanent magnet (12) for detecting a change in the azimuth of magnetic flux of the permanent magnet (12) thereby to sense a rotational angle of the throttle valve (7).

Abstract: A throttle valve control device for an internal combustion engine is obtained which has an improved sector gear 20 capable of suppressing inclinations of tooth surfaces 22a of its resin teeth 22 due to shrinkage of a resin upon hardening thereof at the time of insert molding. The throttle valve control device includes a motor 2 and the sector gear 20 operatively connected with the motor 2 for driving a shaft 8, on which a throttle valve 20 is fixedly mounted, by means of power transmitted thereto from said motor. The sector gear 20 has a sector-shaped rigid core member 21, and a resin molded portion 23 with the teeth 22 formed on the core member 21 by insert molding. The core member 21 has a support portion 24 with a curved surface 24a formed to extend along bottoms 22b of the teeth 22 and project in an axial direction as well.

Abstract: A throttle valve control device for an internal combustion engine is obtained which has an improved sector gear 20 capable of suppressing inclinations of tooth surfaces 22a of its resin teeth 22 due to shrinkage of a resin upon hardening thereof at the time of insert molding. The throttle valve control device includes a motor 2 and the sector gear 20 operatively connected with the motor 2 for driving a shaft 8, on which a throttle valve 20 is fixedly mounted, by means of power transmitted thereto from said motor. The sector gear 20 has a sector-shaped rigid core member 21, and a resin molded portion 23 with the teeth 22 formed on the core member 21 by insert molding. The core member 21 has a support portion 24 with a curved surface 24a formed to extend along bottoms 22b of the teeth 22 and project in an axial direction as well.