Double-column control valve of ejector

Abstract

The invention discloses a double-column control valve of an ejector. The double-column control valve comprises a control plunger, a valve sleeve, a porous plate and a fastening valve seat. A control cavity is defined by the porous plate, the valve sleeve and the control plunger. The double-column control valve further comprises two vertically-overlapped pressure relief floating columns which are cylindrical. Each pressure relief floating column is provided with a pressure relief oil outlet hole and an inlet conical hole, wherein the inlet conical hole is located at the lower end of the pressure relief oil outlet hole, and the pressure relied oil outlet hole and the inlet conical hole communicate and axially run through the pressure relief floating column. The porous plate is provided witha constraint hole and a porous plate oil outlet hole. The constraint hole is formed in the lower portion of the porous plate and matched with the pressure relief floating columns. The porous plate oiloutlet hole and the constraint hole communicate through a conical pore section and run through the porous plate. The two pressure relief floating columns are arranged in the constraint hole. An opening of the lower end of the constraint hole is provided with an elastic collar. The elastic collar limits the vertical movements of the pressure relief floating columns in the constraint hole. By meansof the double-column control valve, the problem of cavitation damage of a high-pressure ejector can be solved, the service life of the ejector is prolonged, and action response is accelerated.

Description

technical field [0001] The invention relates to a control valve, in particular to a double-column 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, t...

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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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