CN106939863B - Fuel injector equipped with metering servo valve - Google Patents
Fuel injector equipped with metering servo valve Download PDFInfo
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- CN106939863B CN106939863B CN201710296653.2A CN201710296653A CN106939863B CN 106939863 B CN106939863 B CN 106939863B CN 201710296653 A CN201710296653 A CN 201710296653A CN 106939863 B CN106939863 B CN 106939863B
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- oil
- metering
- servo valve
- rod
- metering servo
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
- F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
- F02M61/10—Other injectors with elongated valve bodies, i.e. of needle-valve type
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
- F02M59/20—Varying fuel delivery in quantity or timing
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fuel-Injection Apparatus (AREA)
Abstract
The invention discloses a fuel oil injector equipped with a metering servo valve, which comprises an oil injector shell, an oil injection nozzle matching part arranged at the lower part of the oil injector shell and the metering servo valve arranged in the oil injector shell, wherein the metering servo valve is opened through a driving electromagnetic valve arranged at the upper part of the oil injector shell, the metering servo valve drives the oil injection nozzle matching part to be opened and closed in the opening and closing processes, the lower end of a control rod in the metering servo valve is connected with the upper end of a needle valve rod in the oil injection nozzle matching part in a flexible mode, and the flexible mode connection at least enables the control rod in the metering servo valve to freely move in X-Y directions and X, Y axes around the rotating direction. The lower end of the control rod in the metering servo valve is connected with the upper end of the needle valve rod in the oil nozzle matching part in a flexible mode, so that the motion interference and the internal damping are reduced to the maximum extent, the up-and-down movement precision of the needle valve rod in the oil nozzle matching part is higher, and the minimum oil quantity control performance is better.
Description
Technical Field
The present invention relates to a fuel injector equipped with a metering servo valve.
Background
A fuel injector for injecting fuel into an internal combustion engine generally includes an injector housing, a nozzle assembly mounted on a lower portion of the injector housing, and a metering servo valve mounted in the injector housing, the metering servo valve being opened by a drive solenoid mounted on an upper portion of the injector housing, the metering servo valve driving the nozzle assembly to open and close during opening and closing.
High-pressure fuel oil from a common rail pipe is generally led into a fuel injector shell through an oil inlet joint and then is divided into two paths, and one path of the high-pressure fuel oil directly reaches the end part of a fuel injection nozzle in a fuel injection nozzle matching part through a middle hole inner cavity in the fuel injector shell and is to be injected; the other way into the control chamber in the metering servovalve. When the fuel oil injector does not work, through accurate calculation, hydraulic pressure generated by a control cavity in the metering servo valve is transmitted to a needle valve rod in an oil injection nozzle matching part through a control rod in the metering servo valve, so that a conical part at the lower end of the needle valve rod is tightly pressed on an inner conical surface in a needle valve body for sealing, and the fuel oil injector does not inject oil.
If the electromagnet in the driving electromagnetic valve is electrified, the metering servo valve is opened through the electromagnet actuating element in the driving electromagnetic valve, so that the pressure of a control chamber in the metering servo valve is reduced, a needle valve rod in the oil nozzle matching part is pushed upwards by upward hydraulic force to move upwards, a conical body part at the lower end of the needle valve rod is separated from an inner conical surface in the needle valve body, an oil nozzle channel at the lower end of the needle valve body is opened, and atomized fuel oil is sprayed to an engine combustion chamber.
In order to realize the functions, the control rod in the metering servo valve and the needle valve rod in the oil nozzle matching part which are connected in series must be accurately calculated to achieve the balance of axial spring force and hydraulic force, wherein the hydraulic force is the most part. Because the control rod in the metering servo valve and the needle valve rod in the oil nozzle matching part need strict hydraulic sealing, the control rod in the metering servo valve and the needle valve rod in the oil nozzle matching part need to be combined by adopting various radial or end face sealing elements for sealing in structural design.
Along with the requirement of more and more fuel oil injector injection times of 9 times of combustion of an engine, the requirement of higher and higher injection quantity stability and higher action reaction speed, the control rod in the metering servo valve and the needle valve rod in the oil injection nozzle matching part are required to be stable and quick in opening and closing actions (ascending and descending), and the smaller the motion damping is, the better the motion damping is, so that the control rod in the metering servo valve, the needle valve rod in the oil injection nozzle matching part and the sealing combination design are the key of the motion quality of the moving part.
In order to achieve the purpose, a control rod in the metering servo valve and a needle valve rod in an oil nozzle matching part are generally designed into a whole, but the manufacturability is poor, and the industrial production cost is high. Therefore, in order to reduce the cost of industrial production and improve the manufacturability of processing, the control rod in the metering servo valve and the needle valve rod in the fuel injection nozzle matching part are generally divided into two parts and connected by adopting various connection modes, for example, the electromagnetic metering valve for the fuel injection nozzle is disclosed in Chinese patent publication No. CN1096549C, wherein the control rod in the metering servo valve is connected with the needle valve rod in the fuel injection nozzle matching part through a baffle disc. The connection mode easily causes motion interference and internal damping, so that the moving precision of a needle valve rod in the oil nozzle matching part is reduced.
The needle valve rod in the oil nozzle matching part needs to have good guidance in the needle valve body, the needle valve rod can only axially move up and down and rotate around the axis in the needle valve body, other degrees of freedom are limited, in order to ensure the integral functions of the control rod in the metering servo valve and the needle valve rod in the oil nozzle matching part which are connected in series, the control rod in the metering servo valve needs to adopt a floating sealing structure design, and the cost and the failure probability of parts produced in an industrialized mode are greatly reduced.
Disclosure of Invention
The present invention has been made keeping in mind the above problems occurring in the prior art fuel injectors for fuel injection of internal combustion engines, and an object of the present invention is to provide a fuel injector equipped with a metering servo valve. The fuel injector with the metering servo valve solves the problems in a simple and economical mode, reduces redundant floating sealing links and reduces the risk of part failure in manufacturing.
In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows:
a fuel oil injector with a metering servo valve comprises an injector shell, an oil nozzle matching part arranged on the lower portion of the injector shell and the metering servo valve arranged in the injector shell, wherein the metering servo valve is opened through a driving electromagnetic valve arranged on the upper portion of the injector shell, and the metering servo valve drives the oil nozzle matching part to be opened and closed in the opening and closing processes.
In a preferred embodiment of the invention, the lower end of the control rod in the metering servo valve is connected with the upper end of the needle valve rod in the oil nozzle matching part through a flexible sleeve.
In a preferred embodiment of the present invention, the lower end of the control rod in the metering servo valve and the upper end of the needle valve rod in the oil nozzle matching part have the same diameter.
In a preferred embodiment of the present invention, there is no or little clearance between the inner bore of the flexible sleeve and the lower end of the control rod in the metering servo valve and the upper end of the needle valve rod in the oil nozzle matching part, so as to ensure that the sealing volume pressure value formed between the end surface of the lower end of the control rod in the metering servo valve and the end surface of the upper end of the needle valve rod in the oil nozzle matching part is less than 10 bar.
In a preferred embodiment of the present invention, the lower end of the control rod in the metering servo valve and the upper end of the needle valve rod in the oil nozzle matching part are provided with ring grooves, so that the flexible sleeve can better seal with the lower end of the control rod in the metering servo valve and the upper end of the needle valve rod in the oil nozzle matching part.
In a preferred embodiment of the invention, the tail part of the lower end of the control rod in the metering servo valve is provided with a circular arc surface to eliminate interference caused by swinging.
Due to the adoption of the technical scheme, the lower end of the control rod in the metering servo valve in the fuel oil injector provided with the metering servo valve is connected with the upper end of the needle valve rod in the oil nozzle matching part in a flexible mode, so that the motion interference and the internal damping are reduced to the maximum extent, the up-and-down movement precision of the needle valve rod in the oil nozzle matching part is higher, and the minimum oil quantity control performance is better.
Drawings
Fig. 1 is a schematic view of a fuel injector equipped with a metering servo valve according to the present invention.
Fig. 2 is an enlarged schematic view at I of fig. 1.
Detailed Description
Referring to fig. 1 and 2, the fuel injector equipped with the metering servo valve shown in the figure comprises an injector housing 2, a high-pressure fuel inlet passage 3 is arranged on one side of the upper part of the injector housing 2, and an oil return passage 24 is arranged on the other side; a metering servovalve outer volume 5 is provided in the injector housing 2. An oil inlet joint 30 is installed on the high-pressure fuel oil inlet passage 3.
A metering servo valve 7 is mounted in the injector housing 2, the metering servo valve 7 being composed of a valve sleeve 14, a control rod return spring 6a and a control rod 6.
The valve sleeve 14 is positioned opposite the injector housing 2 by means of a step 16 and a cylindrical section 17. The entire metering servovalve 7 is held in the injector housing 2 by a screw plug 18, with the control rod 6 only being able to move up and down axially and to rotate about its axis. The control lever 6 is restored by means of a control lever restoring spring 6 a.
A function hole 13 connected with the upper end of the control rod 6 is arranged below the middle part in the valve sleeve 14, the upper end of the control rod 6 is inserted into the function hole 13, and the function hole 13 enables the control rod 6 to axially move relative to the valve sleeve 14 and simultaneously ensures the sealing between the function hole 13 and the control rod 6.
The control chamber volume 15, which is delimited by the top face of the upper end of the control rod 6, the bore top face of the functional bore 13 and a part of the circumferential face of the functional bore 13, is pressure-independent of the metering valve external volume 5. The control chamber volume 15 is communicated with the high-pressure fuel oil inlet channel 3 in the oil injector shell 2 through an oil inlet metering hole 8 arranged on the valve sleeve 14, and meanwhile, the control chamber volume 15 is also communicated with the oil return channel 24 through an oil outlet metering hole 9 arranged on the valve sleeve 14.
A driving electromagnetic valve 31 is installed on the upper part of the injector shell 2, and when the driving electromagnetic valve is electrified, a ball 31a in the driving electromagnetic valve 31 opens the oil through and leakage metering hole 9, so that the oil through and leakage metering hole 9 is communicated with the oil return channel 24. If the driving solenoid valve is de-energized, the ball 31a in the driving solenoid valve 31 will close the oil through/out metering hole 9, so that the oil through/out metering hole 9 is not communicated with the oil return passage 24.
At the lower axial end of the injector housing 2, a nozzle adapter 23 is connected via a nozzle locking cap 20. The oil nozzle matching part 23 consists of a needle valve body 4 and a needle valve rod 9, and the end face 22 and the outer cylinder 21 of the needle valve body 4 are positioned and fixed with the oil nozzle fastening cap 20 and the bottom surface of the oil injector shell 2.
There is a section cylinder cooperation section 13a between needle valve rod 9 and the needle valve body 4, and cylinder cooperation section 13a makes needle valve rod 9 carry out axial displacement relatively the needle valve body 4, can guarantee simultaneously that the gap of cylinder cooperation section 13a is sealed again, and the cone portion 25 of needle valve rod 9 lower extreme is sealed with interior conical surface 26 in the needle valve body 4, and sealed diameter is d in the drawing. The needle valve stem 9 can thus be moved axially up and down in the needle valve body 4 until the conical portion 25 at the lower end of the needle valve stem 9 coincides with the internal conical surface 26 in the needle valve body 4. The bottom of the needle valve body 4 is provided with an oil injection hole 32.
The diameter of the upper end 27 of the needle valve rod 9 is the same as that of the lower end 28 of the control rod 6, the upper end 27 of the needle valve rod 9 and the lower end 28 of the control rod 6 are connected through the flexible sleeve 10, the inner hole of the flexible sleeve 10 is matched with the upper end 27 of the needle valve rod 9 and the lower end 28 of the control rod 6, and the gap between the matching end 12 between the inner hole of the flexible sleeve 10 and the upper end 27 of the needle valve rod 9 and the gap between the matching end 12a between the inner hole of the flexible sleeve 10 and the lower end 28 of the control rod 6 are small or zero, so that the pressure value of the sealed volume 11 formed by the end head of the upper end 27 of the needle valve rod 9 and the end head of the lower end 28 of the control rod 6 due to structural design is small (for example, less than 10 bar).
With the increasing injection pressure requirements of the engine, the design of the leakless structure will be commonly adopted, the typical leakless structure shown in the figure is that the external volume 5 of the metering valve in the injector housing 2 and the inner cavity of the needle valve body 4 are both the injection working pressure of the injector, and the assembly composed of the control rod 6 and the needle valve rod 9 is placed in the injection high pressure.
The oil nozzle matching part 23 injects or stops oil according to the work requirement of the fuel oil injector, and is realized by the upward movement or the downward movement of the needle valve rod 9 in the oil nozzle matching part through the pressing sealing line d, and along with the higher and higher emission requirement of an engine, the requirement of each oil injection is accurate, the movement position of the needle valve is required to be accurate, and the repeated stability in the whole working process is good.
The invention divides the control rod 6 and the needle valve rod 9 into two parts for reducing the manufacturing cost, and the two parts are flexibly connected by a flexible sleeve 10. At least the control rod 6 in the metering servo valve 7 is free in both the X-Y directions of movement and the X, Y axis about the direction of rotation.
The needle valve rod 9 and the control rod 6 form an assembly, one end is connected with the control chamber volume 15, and the other end is connected with the nozzle hole 32 at the bottom of the needle valve body 4 in the fuel injection nozzle matching part 23, the stress is very complex in the actual working process, the axial force is required to be accurately controlled, the main part of the axial force is hydraulic pressure, in order to reduce the control factor, only F (generated by the pressure of the control chamber volume 15) and F (generated by the sealing section d of the needle valve rod 9) in the control image are designed, and the force is accurately calculated and verified when the fuel injector is designed, and the axial additional force is not allowed to be generated.
Meanwhile, the needle valve rod 9 and the control rod 6 which are connected through the flexible sleeve 10 can reduce the motion interference to the maximum extent during working, so that the component moving precision is higher, and the minimum oil quantity control performance is better.
In order to play the role, the ring grooves 19 and 19a are designed on the upper end 27 of the needle valve rod 9 and the lower end 28 of the control rod 6, so that the flexible sleeve 10 has better sealing performance with the upper end 27 of the needle valve rod 9 and the lower end 28 of the control rod 6.
Meanwhile, in order to make the rod swing, the tail end face of the control rod 6 is designed into an arc surface 29, so that interference caused by swing is eliminated.
Claims (4)
1. A fuel oil injector equipped with a metering servo valve comprises an oil injector shell, an oil injection nozzle matching part arranged at the lower part of the oil injector shell and the metering servo valve arranged in the oil injector shell, wherein the metering servo valve is opened through a driving electromagnetic valve arranged at the upper part of the oil injector shell, and the metering servo valve drives the oil injection nozzle matching part to be opened and closed in the opening and closing processes;
the lower end of a control rod in the metering servo valve is connected with the upper end of a needle valve rod in the oil nozzle matching part through a flexible sleeve;
and a gap is not formed or is small between the inner hole of the flexible sleeve and the lower end of the control rod in the metering servo valve and the upper end of the needle valve rod in the oil nozzle matching part, so that the sealing volume pressure value formed between the end surface of the lower end of the control rod in the metering servo valve and the end surface of the upper end of the needle valve rod in the oil nozzle matching part is ensured to be less than 10 bar.
2. A fuel injector equipped with a metering servovalve as set forth in claim 1, characterized in that the lower end of the control rod in said metering servovalve and the upper end of the needle stem in said injector nozzle partner are the same diameter.
3. A fuel injector equipped with a metering servovalve as set forth in claim 1, characterized in that annular grooves are provided on both of a lower end of a control rod in said metering servovalve and an upper end of a needle stem in said injector partner.
4. A fuel injector equipped with a metering servovalve as set forth in claim 1, characterized in that a lower end tail portion of a control rod in said metering servovalve is provided with a circular arc surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710296653.2A CN106939863B (en) | 2017-04-28 | 2017-04-28 | Fuel injector equipped with metering servo valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710296653.2A CN106939863B (en) | 2017-04-28 | 2017-04-28 | Fuel injector equipped with metering servo valve |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106939863A CN106939863A (en) | 2017-07-11 |
| CN106939863B true CN106939863B (en) | 2022-05-17 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710296653.2A Active CN106939863B (en) | 2017-04-28 | 2017-04-28 | Fuel injector equipped with metering servo valve |
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| Country | Link |
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| CN (1) | CN106939863B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1327509A (en) * | 1999-11-12 | 2001-12-19 | 罗伯特·博施有限公司 | Fuel injection valve |
| CN101614175A (en) * | 2008-06-27 | 2009-12-30 | C.R.F.索奇埃塔·孔索尔蒂莱·佩尔·阿齐奥尼 | The fuel injector that is used for internal-combustion engine with high stability of operation |
| DE102008040108A1 (en) * | 2008-07-03 | 2010-01-07 | Robert Bosch Gmbh | Valve e.g. injecting valve, for use in e.g. fuel injecting system, has valve housing, valve seat carrier, valve needle with valve closure unit, and valve closure spring, where one of above components is made of fiber-reinforced material |
| CN201486716U (en) * | 2009-05-18 | 2010-05-26 | 山东菏泽华星油泵油嘴有限公司 | Flexible needle valve spray nozzle coupler |
| CN103644057A (en) * | 2013-12-30 | 2014-03-19 | 南岳电控(衡阳)工业技术有限公司 | Fuel injector capable of injecting fuel to engine quantitatively at fixed time in controllable manner |
| CN206681895U (en) * | 2017-04-28 | 2017-11-28 | 南岳电控（衡阳）工业技术股份有限公司 | A kind of fuel oil injector equipped with metering servovalve |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102006052817A1 (en) * | 2006-11-09 | 2008-05-15 | Robert Bosch Gmbh | Fuel injection valve for e.g. direct injection of fuel into combustion chamber of internal combustion engine, has valve seat body and closing body provided with rigidity-reducing element that is designed as recess i.e. circulating groove |
-
2017
- 2017-04-28 CN CN201710296653.2A patent/CN106939863B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1327509A (en) * | 1999-11-12 | 2001-12-19 | 罗伯特·博施有限公司 | Fuel injection valve |
| CN101614175A (en) * | 2008-06-27 | 2009-12-30 | C.R.F.索奇埃塔·孔索尔蒂莱·佩尔·阿齐奥尼 | The fuel injector that is used for internal-combustion engine with high stability of operation |
| DE102008040108A1 (en) * | 2008-07-03 | 2010-01-07 | Robert Bosch Gmbh | Valve e.g. injecting valve, for use in e.g. fuel injecting system, has valve housing, valve seat carrier, valve needle with valve closure unit, and valve closure spring, where one of above components is made of fiber-reinforced material |
| CN201486716U (en) * | 2009-05-18 | 2010-05-26 | 山东菏泽华星油泵油嘴有限公司 | Flexible needle valve spray nozzle coupler |
| CN103644057A (en) * | 2013-12-30 | 2014-03-19 | 南岳电控(衡阳)工业技术有限公司 | Fuel injector capable of injecting fuel to engine quantitatively at fixed time in controllable manner |
| CN206681895U (en) * | 2017-04-28 | 2017-11-28 | 南岳电控（衡阳）工业技术股份有限公司 | A kind of fuel oil injector equipped with metering servovalve |
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| CN106939863A (en) | 2017-07-11 |
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