阅读说明：本技术 微泄漏装置及共轨管 (Micro-leakage device and common rail pipe ) 是由 王光明 谢凤 徐帅卿 刘云霞 魏工杰 于 2019-06-28 设计创作，主要内容包括：本发明公开了一种微泄漏装置及共轨管,微泄漏装置包括阀座,阀座内设有阀座油道,阀座设有与阀座油道相连通的进油口和回油口,阀座内设有阀芯和第一限位结构,阀芯与阀座间隙配合,阀芯与阀座之间的间隙分别与进油口和回油口相连通,阀芯的两端分别为阀芯第一端和阀芯第二端,沿燃油流动方向,阀芯第一端位于阀芯第二端的上游,阀芯第二端抵靠于第一限位结构。本发明通过在共轨管上增加微泄漏装置,当轨压过高时,通过微泄漏装置外泄,卸掉过高的轨压,使得发动机实际轨压与设定轨压跟随性好,解决了微泄漏喷油器轨压跟随性差的问题。(The invention discloses a micro-leakage device and a common rail pipe, wherein the micro-leakage device comprises a valve seat, a valve seat oil duct is arranged in the valve seat, the valve seat is provided with an oil inlet and an oil return port which are communicated with the valve seat oil duct, a valve core and a first limiting structure are arranged in the valve seat, the valve core is in clearance fit with the valve seat, a gap between the valve core and the valve seat is respectively communicated with the oil inlet and the oil return port, the two ends of the valve core are respectively a first end of the valve core and a second end of the valve core, the first end of the valve core is positioned at the upstream of the second end of the valve core along. According to the micro-leakage oil sprayer, the micro-leakage device is additionally arranged on the common rail pipe, when the rail pressure is too high, the micro-leakage device leaks, and the too high rail pressure is discharged, so that the following performance of the actual rail pressure and the set rail pressure of the engine is good, and the problem of poor rail pressure following performance of the micro-leakage oil sprayer is solved.)

1. A microleakage device, comprising: the fuel injection valve comprises a valve seat, wherein a valve seat oil duct is arranged in the valve seat, the valve seat is provided with an oil inlet and an oil return port which are communicated with the valve seat oil duct, a valve core and a first limiting structure are arranged in the valve seat, the valve core is in clearance fit with the valve seat, a gap between the valve core and the valve seat is respectively communicated with the oil inlet and the oil return port, the two ends of the valve core are respectively a first end of the valve core and a second end of the valve core, the first end of the valve core is located at the upstream of the second end of the valve core along the flowing direction of fuel, and the second end of.

2. The microleakage device of claim 1, wherein said poppet is micron-sized in clearance from said valve seat.

3. A microleakage device as in claim 1, wherein said valve element is non-interchangeable with said valve seat.

4. A microleakage apparatus as in claim 1, wherein said second end of said core has an oil drainage groove formed in an end surface thereof.

5. A micro-leakage device as claimed in claim 4, wherein said valve seat has an annular oil groove on its inner surface, said annular oil groove is covered on the outside of said second end of said valve core, one end of said annular oil groove is connected to the gap between said valve seat and said valve core, and the other end of said annular oil groove is connected to said oil drainage groove.

6. The micro-leakage device according to claim 4, wherein the first limiting structure is a limiting ring fixed on the inner surface of the valve seat, the second end of the valve element abuts against the limiting ring, an inner cavity defined by the limiting ring is a limiting ring oil passage, one end of the limiting ring oil passage is communicated with the oil drainage groove, and the other end of the limiting ring oil passage is communicated with the oil return opening.

7. A microleakage apparatus as in claim 1, wherein said valve seat has a retaining groove formed in an inner surface thereof, said retaining groove having an annular retaining ring disposed therein, said first end of said valve element being disposed against said retaining ring.

8. The common rail pipe is internally provided with a common rail pipe oil passage, and is characterized in that one end of the common rail pipe is fixedly provided with the micro-leakage device according to any one of claims 1 to 7, and the oil inlet is communicated with the common rail pipe oil passage.

9. The common rail of claim 8, wherein said valve seat is threadably connected to said common rail.

Technical Field

The invention relates to the technical field of engines, in particular to a micro-leakage device and a common rail pipe.

Background

When the high-pressure common rail engine is in actual application, the problem of poor following performance exists between the actual rail pressure of the common rail pipe and the set rail pressure, namely the actual rail pressure lags behind the set rail pressure, and in order to solve the problems, the following three schemes are generally adopted in the prior art:

(1) the common rail fuel system is unchanged, the static leakage fuel injector is replaced by a non-static leakage fuel injector, and meanwhile, an idle injection strategy is used;

(2) the oil injector in the common rail system adopts a static leakage-free oil injector, an electric control pressure relief valve is added on a common rail pipe, and the rail pressure control is realized by controlling the electric control pressure relief valve through an ECU (electronic control Unit);

(3) increase the pressure release unit on the common rail pipe, the pressure release unit contains plunger and spring, and the rail pressure overcomes the spring pretightning force and opens the plunger, carries out the leakage of high-pressure fuel.

However, the above three technical solutions have the following problems:

disadvantages of scheme (1): the empty injection strategy is to open and close a ball valve of the oil injector at high frequency, so that the valve seat is easy to wear seriously, and the service life of the oil injector is shortened; in addition, the oil nozzle is not closed tightly after the oil injector is aged, so that fuel oil is injected into a combustion chamber, and the emission is deteriorated.

Disadvantages of scheme (2): an electric control pressure release valve is additionally arranged on the common rail pipe, so that the cost is high, the calibration is complex, and the development period is prolonged.

The disadvantage of scheme (3): the conventional machining process for the pressure relief hole in the common rail pipe has the advantages that the diameter is more than 0.1mm, the diameter is close to that of a nozzle orifice, the hole diameter is too large, high-pressure fuel oil is leaked too much, the oil balance of a common rail system cannot meet the requirement, and the rail pressure cannot reach a set value.

Disclosure of Invention

In view of the above problems, the first technical problem to be solved by the present invention is: a micro-leak device is provided that allows for the removal of a portion of the rail pressure.

Based on the same inventive concept, the second technical problem to be solved by the invention is as follows: the common rail pipe applying the micro-leakage device is provided to solve the problem that the rail pressure following performance of the oil sprayer without static leakage is poor.

To solve the first technical problem, a first technical solution of the present invention is:

a microleakage device, comprising: the fuel injection valve comprises a valve seat, wherein a valve seat oil duct is arranged in the valve seat, the valve seat is provided with an oil inlet and an oil return port which are communicated with the valve seat oil duct, a valve core and a first limiting structure are arranged in the valve seat, the valve core is in clearance fit with the valve seat, a first valve core end and a second valve core end are respectively arranged at two ends of the valve core, the first valve core end is located at the upstream of the second valve core end along the flow direction of fuel, and the second valve core end is abutted against the first limiting structure.

Preferably, the clearance between the valve core and the valve seat is in a micron order.

Preferably, there is no interchangeability between the poppet and the valve seat.

Preferably, an oil drainage groove is formed in the end face of the second end of the valve core.

Preferably, the inner surface of the valve seat is provided with an annular oil groove, the annular oil groove covers the outer part of the second end of the valve core, one end of the annular oil groove is communicated with a gap between the valve seat and the valve core, and the other end of the annular oil groove is communicated with the oil drainage groove.

Preferably, the first limiting structure is a limiting ring fixed on the inner surface of the valve seat, the second end of the valve core abuts against the limiting ring, an inner cavity defined by the limiting ring is a limiting ring oil duct, one end of the limiting ring oil duct is communicated with the oil drainage groove, and the other end of the limiting ring oil duct is communicated with the oil return opening.

Preferably, the inner surface of the valve seat is provided with a limiting groove, an annular retaining ring is arranged in the limiting groove, and the first end of the valve core abuts against the retaining ring.

To solve the second technical problem, a second technical solution of the present invention is:

the common rail pipe is internally provided with a common rail pipe oil passage, one end of the common rail pipe is fixedly provided with the micro-leakage device, and the oil inlet is communicated with the common rail pipe oil passage.

Preferably, the valve seat is threadedly connected to the common rail pipe.

After the technical scheme is adopted, the invention has the beneficial effects that:

according to the micro-leakage oil sprayer, the micro-leakage device is additionally arranged on the common rail pipe, when the rail pressure is too high, the micro-leakage device leaks, and the too high rail pressure is discharged, so that the following performance of the actual rail pressure and the set rail pressure of the engine is good, and the problem of poor rail pressure following performance of the micro-leakage oil sprayer is solved.

Because the clearance between the valve seat and the valve core is in a micron order, the clearance is small, and the fuel leakage amount is small, thereby realizing the micro-leakage of the fuel, ensuring the followability of the actual rail pressure and the set rail pressure, and simultaneously not influencing the oil mass balance of the engine.

Because the valve seat and the valve core are matched by matching parts, namely the valve seat and the valve core have no interchangeability, the valve core and the valve seat cannot be clamped and blocked, and the structure is reliable.

Drawings

FIG. 1 is a schematic cross-sectional view of the assembly of a microleakage device of the present invention with a common rail;

FIG. 2 is a perspective view of a second end of the valve cartridge of FIG. 1;

FIG. 3 is an oil circuit diagram of an engine micro-leak fuel system;

FIG. 4 is a time-pressure plot of engine rail pressure following test-rail pressure drop;

in the figure: 1-common rail pipe; 11-common rail oil duct; 2-a valve core; 21-an oil drainage groove; 3-a retainer ring; 4-valve seat; 41-a limiting groove; 42-annular oil groove; 43-limiting ring oil duct; 44-a stop collar; 45-oil inlet; 46-oil return port; 5-an oil sprayer; 6-an oil injection pump; 7-oil tank.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The arrows shown in fig. 3 indicate the fuel flow direction.

As shown in fig. 1 and fig. 2, a micro-leakage device comprises a valve seat 4, a valve seat oil passage is arranged in the valve seat 4, the valve seat 4 is provided with an oil inlet 45 and an oil return port 46 which are communicated with the valve seat oil passage, the surface of the oil inlet end of the valve seat 4 is provided with an external thread, a valve core 2 is arranged in the valve seat 4, the valve seat 4 is in clearance fit with the valve core 2, the clearance is micron-sized, the valve seat 4 is in matching part fit with the valve core 2, and the valve core 2 does not have interchangeability, the two ends of the valve core 2 are respectively a first end of the valve core and a second end of the valve core, the first end of the valve core is positioned at the upstream of the second end of the valve core, the first end of the valve core is abutted against an annular retainer ring 3, the second end of the valve core is abutted against a limit ring 44, the end surface, the drain groove 21 communicates with the annular oil groove 42.

As shown in fig. 1, the inner surface of the valve seat 4 is provided with an annular limiting groove 41, and the retainer ring 3 is disposed in the limiting groove 41. The limiting ring 44 is fixed on the inner surface of the valve seat 4, a cavity surrounded by the limiting ring 44 is a limiting ring oil duct 43, one end of the limiting ring oil duct 43 is communicated with the oil drainage groove 21, and the other end is communicated with the oil return opening 46.

As shown in fig. 1, when the micro-leakage device is assembled with the common rail pipe 1, the valve seat 4 is connected to the common rail pipe 1 by screw threads, the common rail pipe oil passage 11 in the common rail pipe 1 is communicated with the oil inlet 45, and the oil return port 46 is connected with the oil return pipe.

As shown in fig. 3, when the engine is in operation, the fuel injection pump 6 pressurizes fuel in the fuel tank 7 and supplies the pressurized fuel to the common rail pipe 1, the common rail pipe 1 distributes the fuel to each fuel injector 5, and return oil generated by the common rail pipe 1 and the fuel injector 5 flows back to the fuel tank 7 through the return oil pipe. When the pressure of the fuel oil in the common rail pipe 1 is too high, the trace fuel oil flows out of the common rail pipe 1 through the oil inlet 45, the retainer ring 3, the gap between the valve seat 4 and the valve core 2, the annular oil groove 42, the oil drainage groove 21, the limiting ring oil duct 43 and the oil return opening 46 in sequence, and then flows back to the oil tank 7 through the oil return pipe.

According to the invention, the micro-leakage device is added on the common rail pipe 1, when the rail pressure is too high, the micro-leakage device leaks, and the too high rail pressure is discharged, so that the problem of poor rail pressure following performance of the micro-leakage oil sprayer is solved, namely as shown in figure 4, the rail pressure of the engine with the micro-leakage device is good in following performance with the set rail pressure of the engine. Meanwhile, the clearance between the valve seat 4 and the valve core 2 is micron-sized, the clearance is small, and the leakage amount of fuel is small, so that the micro-leakage of the fuel is realized, the following performance of the actual rail pressure and the set rail pressure is ensured, and the oil mass balance of an engine cannot be influenced; in addition, the valve seat 4 and the valve core 2 are matched by matching parts without interchangeability, so that the valve core 2 and the valve seat 4 cannot be clamped and the structure is reliable.

The foregoing is illustrative of the best mode of the invention and details not described herein are within the common general knowledge of a person of ordinary skill in the art. The scope of the present invention is defined by the appended claims, and any equivalent modifications based on the technical teaching of the present invention are also within the scope of the present invention.