Composite in-out oil valve common rail oil pump

Abstract

The invention discloses a composite in-out oil valve common rail oil pump. The oil pump comprises an in-out oil valve body (15), an oil outlet channel (803), an oil inlet channel (801) and an oil inlet valve steel ball (7); the in-out oil valve body is assembled in an inner cavity of an oil injection pump body (4); an oil inlet steel ball seat hole (802) and an oil outlet steel ball seat hole (804) contacting and sealing steel balls are formed in the centers of the upper and lower shaft ends of the in-out oil valve body; the oil outlet channel is coaxially assembled at the lower end surface of an oil outlet joint (14), provides pressure oil for a high-pressure cavity under the action of a plunger (3), obliquely extends from the end surface of the bottom of the in-out oil valve body to the oil outlet steel ball seat hole positioned in the center of the upper end to form a high-pressure oil channel communicated with the upper part of the plunger and the lower part of an oil outlet valve steel ball (9); the oil inlet channel is communicated with a low-pressure channel, is downwards obliquely communicated with the oil inlet steel ball seat hole in the center of the lower end from the waist part of a cylinder of the in-out oil valve body; the oil inlet valve steel ball (7) opens and closes the oil inlet channel under the action of an in-out oil valve spring (5). One in-out oil valve body is adopted to replace two parts of an oil inlet valve body and an oil outlet valve body, the high-pressure volume is reduced by a half, and the whole dimension is greatly reduced.

Description

technical field [0001] The invention relates to a common rail system of a diesel engine, which adopts a high-pressure oil pump with an oil inlet and outlet valve device. Background technique [0002] exist figure 2 In the high-pressure oil pump of the prior art high-pressure common rail system shown, the oil inlet and outlet valves include: a fuel injection pump body 4 with a coaxial stepped inner cavity, and an oil inlet valve body 8 coaxially installed in the inner cavity of the fuel injection pump body 4 , an oil inlet steel ball seat hole 802 is formed in the center of the oil inlet valve body 8, the lower end of the oil inlet steel ball seat hole 802 is connected with the oil inlet passage 801 formed on the oil inlet valve body 8, and the oil inlet steel ball The upper end of the seat hole 802 is formed with a tapered surface that contacts the steel ball 7 of the oil inlet valve for sealing, and on the upper end surface of the oil inlet valve body 8, there is an oil ou...

AI Technical Summary

Problems solved by technology

[0003] In the oil inlet and outlet valves of the high-pressure oil pump composed of the above-mentioned prior art parts, the valve body that completes the oil inlet and outlet functions is composed of the oil inlet valve body 8 and the oil outlet valve body 10 respectively, and the oil inlet valve body and the oil outlet valve body are formed. The disadvantage of the oil inlet valve is that the axial dimension is large, the cost is high, and the manufacturing precision is difficult to guarantee. At the same time, the overall axial dimension of the oil pump is increased, which in turn affects the size matching between the oil pump and the small displacement engine.

Due to the hard seal between the upper plane of the oil inlet valve body 8 and the lower plane of the oil outlet valve body 10, it needs to withstand a high pressure of 160-180 MPa, and the technical difficulty of not leaking is difficult to achieve absolutely, and there is a greater risk sex

From the analysis of the efficiency of the oil pump, it can be seen that the high-pressure volume of the above-mentioned prior art is composed of two parts, one part occupies the cavity where the steel ball 7 of the oil inlet valve in the upper oil circuit is located, and the other part occupies the cavity where the steel ball 9 of the oil outlet valve is located. The high-pressure volume occupied by the two oil inlet and outlet valve bodies is twice that of one valve body, thus greatly reducing the oil supply efficiency of the oil pump

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