Keihin Corporation

Akira Akabane

Kenichi Sato

Yuki Fujino

Hirokazu Tanuma

A rotation angle detector includes: a magnet attached to a rotating shaft and magnetized in a certain direction orthogonal to an axis of the rotating shaft; and a non-rotary magneto-electric transducer placed to be opposed to an end surface of the magnet, and configured to detect a rotation angle of the rotating shaft in cooperation with the magnet through magneto-electric transduction. A concave curved surface is formed in the end surface of the magnet in order to make a magnetic flux of a magnetic field facing the end surface of the magnet closer to the magnet and flattened. Accordingly, it is possible to provide a rotation angle detector which is compact in size and has a stable accuracy for detecting the rotation angle, by making the curvature of the magnetic flux near the end surface of the magnet small and placing the magneto-electric transducer in that location.

Rotation angle detector

A process for producing an electromagnetic fuel injection valve is provided, the electromagnetic fuel injection valve having a structure in which a valve assembly formed by coaxially joining a movable core and a valve body is spring-biased toward the side on which the valve assembly is seated on a valve seat while restricting an end thereof that is in proximity to a fixed core, and in the process a first distance (L) between the front end of the fixed core () and the front end of a cylindrical magnetic body () is measured, a stopper () and the movable core () are formed so that a second distance (L) between an annular shoulder portion () of a valve seat member () and the rear end of the stopper () projecting by a predetermined amount from the rear end of the movable core () in a state in which the valve seat member () and the valve assembly () are held coaxially is smaller than the first distance (L) by a desired value, and the cylindrical magnetic body () and the valve seat member () are butt-welded in a state in which a tubular press-fit portion () is press-fitted into a front portion of the cylindrical magnetic body () until the annular shoulder portion () abuts against the front end of the cylindrical magnetic body (). This enables the stroke of the valve body to be adjusted easily while reducing the cost, and the valve seat member and the cylindrical magnetic body to be joined while enhancing the coaxial precision.

Process for producing electromagnetic fuel injection valve

An electromagnetic fuel injection valve is provided in which a cylindrical magnetic body is welded to a valve seat member having at the rear end thereof a tubular press-fit portion press-fitted into a front portion of the cylindrical magnetic body, a valve body is housed in the valve seat member while being spring-biased in a direction that seats the valve body on a valve seat, and a movable core facing a fixed core is coaxially connected to the valve body, wherein the valve seat member () includes the tubular press-fit portion (), a large diameter portion () that has substantially the same outer diameter as the outer diameter of the cylindrical magnetic body (), and an annular shoulder portion () that is formed as a flat face perpendicular to the outer peripheral face of the tubular press-fit portion () and provides a connection between the tubular press-fit portion () and the large diameter portion (), an annular abutment receiving face () at the front end of the cylindrical magnetic body () is formed so as to define a right angle relative to the inner peripheral face of the cylindrical magnetic body (), the annular abutment receiving face () abutting against the annular shoulder portion () over substantially the entire face, and the front end of the cylindrical magnetic body () and the abutment portion of the valve seat member () are welded together along the entire periphery. This enables the thickness of the cylindrical magnetic body to be reduced, thus making it small and improving the responsiveness.

Electromagnetic fuel injection valve

An electromagnetic fuel injection valve in which a first resin-molded layer that is made of a synthetic resin, covers a solenoid section, and forms a coupler main portion that defines a coupler is covered by a second resin-molded layer different from that of the first resin-molded layer so that an outer face of the coupler main portion is exposed from a middle part up to the extremity of the coupler main portion. An endless engagement groove is provided on the outer periphery of the middle pad of the coupler main portion of the first resin-molded layer, the second resin-molded layer engaging with the endless engagement groove. An extending portion extending further outward than the engagement groove is formed in the second resin-molded layer so that the extending portion makes contact with an outer face of the coupler main portion when in a non-engaged state and covers the coupler main portion.

In an electromagnetic fuel injection valve designed so that the contact of a movable attraction face at a rear end of a movable core with a stationary attraction face included at a front end of a stationary core is inhibited, a ring-shaped stopper () made of a material non-magnetic or magnetic weakly more than a movable core () is press-fitted into an inner periphery of a rear portion of the movable core (), and a flat abutment face (), which is disposed at a location displaced from a flat movable attraction face () formed at the rear end of the movable core () toward a stationary attraction face (), is formed at a rear end of the stopper () to be able to abut against the stationary attraction face. A slant () is formed on an inner periphery of the rear end of the movable core () and an outer periphery of the rear end of the stopper () to continuously and smoothly connect the movable attraction face () and the abutment face () to each other. Thus, the accumulation and deposition of chips and a magnetic powder can be prevented, and the area of application of an electromagnetic attraction force to the movable core can be increased substantially, while decreasing the number of parts and the number of assembling steps to provide a reduction in cost.

Electromagnetic fuel injection valve and process for producing the same

In an electromagnetic fuel injection valve in which a valve assembly formed by integrally connecting a valve element and a movable core to each other is contained in a valve housing, and a first journal part and a second journal part are provided in the valve assembly so as to be supported slidably in the guide hole in a valve housing, the outside surface of the first journal part () is formed by a sliding surface () slidable on the inside surface of the guide hole () and a pair of tapered tilt surfaces () connecting to both the front and rear sides of the sliding surface (); at least the tilt surface () on the movable core side, of both the tilt surfaces (), is formed of a first tilt surface part () connecting to an end part of the sliding surface () and a second tilt surface part () connecting to the first tilt surface part (); and an angle that the first tilt surface part () makes with a plane perpendicular to the axis line of a valve shaft part () is set larger than an angle that the second tilt surface part () makes with the plane. Whereby a decrease in initial fitting property and an increase in abrasion loss can be avoided, and the weight of the valve assembly can be reduced while good response and flow characteristic are maintained.

In an electromagnetic fuel injection valve in which a non-magnetic cylinder is coaxially coupled at its front end to a rear end of a magnetic cylinder forming a portion of a valve housing to surround a portion of a movable core having a rear end face serving as a movable attraction face, and a stationary core having a front end face serving as a stationary attraction face is fitted and fixed at its front portion in a rear portion of the non-magnetic cylinder, so that the stationary attraction face is opposed to the movable attraction face, the stationary core () is fitted and fixed at its front portion in the non-magnetic cylinder (), so that it is in close contact with an inner surface of an intermediate portion of the non-magnetic cylinder () in a region corresponding to the stationary attraction face (), and an annular recess () having a flat portion () flush connected to the stationary attraction face () is provided in an inner surface of the non-magnetic cylinder () to form an annular chamber () between the annular recess () and an outer periphery of a rear portion of the movable core (). This makes it possible that the area of opposed faces of the stationary core and the movable core is set at a large value to the utmost, thereby preventing the accumulation and deposition of chips and a magnetic powder.

An electromagnetic fuel injection valve having a cylindrical magnetic body, the front end of a cylindrical non-magnetic body surrounding a part of a movable core coaxially connected to a valve body is connected coaxially to the rear end of the cylindrical magnetic body, and a fixed core is fitted into and fixed to a rear portion of the cylindrical non-magnetic body, wherein the movable core includes a tubular sliding portion having an outer peripheral face that is in sliding contact with an inner peripheral face of a rear portion of the cylindrical magnetic body, a rear tubular opposing portion, and a front tubular opposing portion, and when the diameter of the rear tubular opposing portion is D, the diameter of the front tubular opposing portion is D, and the diameter of the tubular sliding portion is D, they are set so that D&#x3c;D&#x3c;D

A fuel injection valve is provided in which a funnel-shaped fuel collecting depression () is provided between a valve seat () and an outlet hole () of a valve seat member (), the depression () collecting fuel that has passed through the valve seat () and guiding it to the outlet hole (), and a flat fuel diffusion chamber () for radially outwardly diffusing fuel that has passed through the outlet hole () and guiding it to a plurality of fuel injection holes () is provided between opposing faces of the valve seat member () and an injector plate (), an inner peripheral face (A) of the outlet hole () being formed along a curved face on the inner peripheral side of a virtual torus (T) so that the inner peripheral face (A) is continuous with the base of the fuel collecting depression () and the roof of the fuel diffusion chamber (). This prevents eddies from being generated when fuel is reversed at the outlet hole of the valve seat member, thus enabling pressure loss of the fuel to be reduced, reduction in the amount of fuel injected to be suppressed, atomization of injected fuel to be promoted, and a spray form to be stabilized.

Fuel injection valve

In a fuel injection valve in which a funnel-shaped fuel collecting recessis provided between a valve seatand an outlet hole, and a flat fuel diffusion chamberwhich diffuses a fuel radially outward and guides the fuel to a plurality of fuel injection holesis provided between opposed surfaces of a valve seat memberand an injector plate, a seating portionhaving a spherical band shape, and a valve tip end portionwhich projects into a cone shape toward a center of the outlet holefrom the seating portionand leaves its top portion in the outlet holeeven at the time of valve opening of a valve bodyare formed at the valve body, a cone angle &#x3b1; of the valve tip end portionis set to be larger than a funnel angle &#x3b2; of the fuel collecting recess, and an inner peripheral surfaceA of the outlet holeis formed along an inner peripheral side curved surface of a virtual torus T so that the inner peripheral surface is connected to a bottom surface of the fuel collecting recessand a ceiling surface of the fuel diffusion chamber. Thus, generation of eddies at the time of reverse of the fuel flow in the outlet hole of the valve seat member is prevented to reduce pressure loss of the fuel, thereby suppressing decrease in the amount of injected fuel, promoting atomization of the injected fuel and stabilizing spray forms.

An electromagnetic fuel injection valve includes a coil assembly housed in a solenoid housing having a cylindrical magnetic metal coil case which integrally has, at one end side, a ring-shaped end wall portion and a press-fit cylindrical portion integrally connected to an inner periphery of the end wall portion so that the magnetic cylindrical body is press-fitted to the press-fit cylindrical portion and the press-fit cylindrical portion is welded to the magnetic cylindrical body, and a flange portion which is provided at a rear end of a fixed core. Wherein at least the solenoid housing is covered with a resin molded part and integrally has a power receiving coupler, the coil case being formed by a burring process to a central portion of a closed end of a bottomed cylindrical material having a circular opening with a smaller diameter than an outer diameter of the press-fit cylindrical portion.

An electromagnetic fuel injection valve has a rear end of a magnetic body coaxially connected to a front portion of a fixed core via a non-magnetic body. A coil assembly surrounds a rear portion of the magnetic body and the fixed core. A bobbin includes a cylindrical portion; a pair of flanges protruding radially outward from opposite ends of the cylindrical portion; and a terminal boss portion protruding sideways from one of the flanges disposed at a side opposite from the magnetic body and to which a pair of power-receiving-side connecting terminals are fixed. Engagement recesses are recessed inward on opposite sides of the terminal boss portion connected to the one flange wherein intermediate portions of a pair of coil ends extending from opposite ends of a coil pass through and engage the engagement recesses and are electrodeposited to a pair of electrodeposition portions provided with the connecting terminals.

An electromagnetic fuel injection valve (I) is provided that includes a fixed core () made of a high hardness ferrite magnetic material, and a movable core () that has fixed thereto by press-fitting a stopper element () that is nonmagnetic or is more weakly magnetic than the movable core (), the stopper element () abutting directly against the fixed core () so as to maintain an air gap (g) between the two cores () and () when a coil () is energized. In this way, high abrasion resistance and responsiveness can be imparted to the fixed core and the movable core without subjecting the two cores to a troublesome abrasion resistance treatment to provide a plating layer, etc., and without providing a valve body stopper plate, thereby contributing to a reduction in the cost of the electromagnetic fuel injection valve.

To prevent a fuel liquid surface within a float chamber from rising when a liquid surface change occurs to make a float rotate so that a float valve opens a valve seat hole, a first float (F ) is arranged in one outer side from one end (F ) of the bearing portion (F ) and in one side (B), one end (F ) of the bearing portion (F ) and the first float (F ) are connected by a first connecting arm portion (F ), a second float (F ) is arranged in another outer side from another end (F ) of the bearing portion (F ) and in one side (B), another end (F ) of the bearing portion (F ) and the second float (F ) are connected by a second connecting arm portion (F ), a first buffer rib (F ) is integrally formed between an outer side surface (F A) of the first connecting arm portion (F ) and another side surface (F ) of the first float (F ), and a second buffer rib (F ) is integrally formed between an outer side surface (FIOA) of the second connecting arm portion (F ) and another side surface (F ) of the second float (F ).

Growing community of inventors

Miyagi, Japan

Akira Akabane