A urea solution injector

Abstract

The invention discloses a urea solution ejector which comprises a fixing iron core, an electromagnetic coil, a spring, a valve bush, a valve seat, a spray hole plate, a bulb, a valve rod, an armature and the like. The urea solution ejector is characterized in that multisurface parts which are evenly distributed are arranged on a guide outer cylinder of the armature, wherein the depth of a cut flat position is smaller than the chord height of the inscribed polygon of the circumference of the armature. The valve bush is a thin-walled sleeve piece, and the specific value of the length to the thickness of the valve bush is greater than or equal to 50; a heat flow resistance effect is achieved on heat flow which is conducted along the valve bush, and the phenomenon that a urea solution is crystallized due to heating is prevented. The surface of a movable part which is composed of the armature, the valve rod and the bulb is provided with a coating. According to the urea solution ejector, the surface coating of the movable part can be increased through the combination of the flat position guide structure of the armature and the thin-walled valve bush; the magnetic field intensity of the electromagnetic coil can be effectively weakened; the friction resistance generated when the armature makes movement in an inner hole of the valve bush is obviously reduced, and the crystallization of the urea solution is restrained; the movement clamping stagnation of the movable part of the armature is avoided.

Description

technical field

[0001] The invention relates to a urea solution injector, which is used for spraying urea solution into an exhaust pipe, so as to avoid movement stagnation of movable parts inside the injector due to lack of lubrication, increased frictional resistance and "crystallization" of urea solution. Automobile exhaust emission control technology field. Background technique

[0002] With the increasingly serious environmental problems and energy crisis, emission regulations are becoming stricter, more and more energy-saving emission reduction technologies are applied to vehicles, among which SCR (Selective Catalytic Reduction) is a method that sprays urea solution into engine exhaust gas technology to clean nitrogen oxide emissions from air streams.

[0003] Since the urea solution medium is an aqueous solution with poor lubricating ability, the friction of the moving parts in the injector at the guide is obviously greater than the resistance of the fuel injection va...

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