Electromagnetic fuel injection valve

摘要

In an electromagnetic fuel injection valve including a magnetic coil housing (31) having a coil assembly (28) housed therein, the coil housing (31) includes the first and second coil housing half bodies (31a, 31b) whose cross sections are each shaped like an inferior arc, and which are oppositely disposed so as to interpose the coil assembly (28) and a coupler (34), each of the coil housing half bodies (31a, 31b) includes: a barrel portion (44) for covering an outer peripheral surface of the coil assembly (28); a front-end wall portion (45) and a rear-end wall portion (46) which are in contact with front-end and rear-end surfaces of the coil assembly (28); a front connection cylindrical portion (47) welded to the outer peripheral surface of the magnetic cylindrical body (4); and a rear connection cylindrical portion (48) welded to the outer peripheral surface of the fixed core (5); both the coil housing half bodies are formed symmetrically; and one half part and the other half part of each of the coil housing half bodies (31a, 31b) in an axial direction are formed symmetrically. Thus, it is possible to provide an electromagnetic fuel injection valve which enables the coil housing to be formed from two identical components, and is inexpensive and good in assembling efficiency, as well as has a better magnetic efficiency.

主权项

1. An electromagnetic fuel injection valve including: a valve housing including a valve seat member with a valve hole in its front end, a magnetic cylindrical body, a non-magnetic cylindrical body, a fixed core and a fuel intake cylinder which are sequentially connected from a front end toward a rear end thereof, an inside of the valve housing serving as a fuel passage; a coil assembly which includes a bobbin and a coil wound therearound and is placed from the fixed core to the non-magnetic cylindrical body on outer peripheries thereof; a coil housing whose opposite end parts are connected to outer peripheral surfaces, respectively, of the fixed core and the magnetic cylindrical body with the coil assembly housed in the coil housing, the coil housing forming a magnetic circuit between the fixed core and the magnetic cylindrical body when the coil assembly is electrified; a valve body for opening and closing the valve hole in cooperation with the valve seat member; a movable core which is connected to the valve body, slidably fitted to an inner peripheral surface of the magnetic cylindrical body, and opens the valve body due to its attraction to the fixed core when the magnetic circuit is formed; and a coupler which is connected to the coil assembly, projects outward of the coil housing, and is formed integrally with a first covering layer, made of synthetic resin, for covering an outer periphery of the coil to embed and seal the coil,
wherein the coil housing includes first and second coil housing half bodies whose cross sections are each shaped like an inferior arc, and which are placed oppositely disposed so as to interpose the coil assembly and the coupler, each of the coil housing half bodies includes: a barrel portion for covering an outer peripheral surface of the coil assembly; a front-end wall portion and a rear-end wall portion which are bent inward in a radial direction from opposite ends of the barrel portion, and are in contact with front-end and rear-end surfaces of the coil assembly; a front connection cylindrical portion extending frontward from an inner end of the front-end wall portion, and fixedly attached to the outer peripheral surface of the magnetic cylindrical body; and a rear connection cylindrical portion extending rearward from an inner end of the rear-end wall portion, and fixedly attached to the outer peripheral surface of the fixed core, the first and second coil housing half bodies are formed symmetrically and outer diameters of the magnetic cylindrical body and the fixed core are set equal to each other, so that one half and the other half part of each of the coil housing half bodies in an axial direction are formed symmetrically, and, between the first and second coil housing half bodies, a first space (S1) is provided on a side where a bottom of the coupler is interposed, a second space (S2) is also provided on a side opposite thereto, the relationship between the first space (S1) and the second space (S2) is set to be S1>S2, and a second covering layer, made of synthetic resin, which the coil assembly and the bottom of the coupler are embedded in and sealed by, is molded around an outer periphery of the valve housing.