Control valve of injector

Abstract

The invention discloses a control valve of an injector. The control valve comprises an ejector body, a control plunger, a valve sleeve, an orifice plate and a fastening valve seat. The orifice plate,the valve sleeve and the control plunger form a control cavity. The control valve of the injector also comprises a pressure relief floating column, and the pressure relief floating column is cylindrical and arranged on the upper end face of the control plunger. The end, close to the control plunger, of the pressure relief floating column is provided with a notch part penetrating through the circumferential surface, and an oil outlet hole is formed in the other end of the pressure relief floating column. The oil outlet hole communicates with the notch part to form a connection channel, the orifice plate is provided with a constraint hole matched with the pressure relief floating column, the constraint hole communicates with an orifice plate oil outlet hole of the orifice plate, and the pressure relief floating column can move up and down in the constraint hole. According to the control valve, the problem of cavitation damage of the high-pressure injector can be solved, the service lifeof the injector is prolonged, and the action response is accelerated.

Description

technical field [0001] The invention relates to a control valve, in particular to a control valve of an injector, and belongs to the technical field of high-pressure common rail fuel injection. Background technique [0002] The control valve is an important part of the fuel injector. It can precisely control the opening of the fuel injector and is the key factor affecting the precise control of the fuel injector. Now the injection pressure requirements of the fuel injector are constantly increasing, and the injection pressure is required to be above 200MPa. At the same time, the hydraulic pressure in the cavity of this type of control valve is also continuously increasing. The oil in the control cavity drops from high pressure (200MPa and above) to 0MPa, which will cause cavitation damage. The higher the oil pressure, the more serious the cavitation damage. The easier the oiler is damaged, the shorter the service life. [0003] In the prior art, for example, the patent stru...

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Problems solved by technology

[0002] The control valve is an important part of the fuel injector. It can accurately control the opening of the fuel injector and is the key factor affecting the precise control of the fuel injector. Now the injection pressure requirements of the fuel injector are constantly increasing, and the injection pressure is required to be above 200MPa. At the same time, the hydraulic pressure in the cavity of this type of control valve is also continuously increasing. The oil in the control cavity drops from a high pressure (200MPa and above) to 0MPa, which will cause cavitation damage. The higher the oil pressure, the more serious the cavitation damage. The easier the oiler is damaged, the shorter the service life

[0003] In the prior art, for example, the patent structure of the publication number: CN103967666B does not have a structure for controlling the pressure drop of the cavity slowly, and high pressure will cause cavitation damage, thereby limiting the working pressure of this type of injector; publication number: DE10190272B4 patent technical manual attached Image 6 The restrictor (148) and socket valve (302) shown in the figure can reduce cavitation damage, but there are many sealing contact surfaces between parts, which increases a certain risk of leakage; publication number: CN101595297B patent end The ball seat valve (110) also has an inlet (122) with a pre-throttling device (126) and a diffuser (128) arranged between the pre-throttle device (126) and the valve seat (120). ), the diffuser (128) can play a pressure buffer role for high oil pressure, the pressure in the diffuser (128) decreases, and the pressure difference after the outflow in the diffuser (128) decreases, reducing cavitation damage, The one-piece structure in this patent is as attached to its description figure 2 As shown, it is a thin hole at both ends and a thick hole in the middle, so the difficulty of manufacturing and processing is very high, and the diffuser (128) of the split structure in this patent is as attached to its description. image 3 As shown, the difficulty of processing is reduced, but a sealing contact plane is added, which also increases the risk of leakage

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