CN1050877C

CN1050877C - A fuel injection valve for a reciprocating internal combustion engine

Info

Publication number: CN1050877C
Application number: CN94101587A
Authority: CN
Inventors: U·施泰格; K·海姆
Original assignee: Winterthur Gas and Diesel AG
Current assignee: Winterthur Gas and Diesel AG
Priority date: 1993-02-17
Filing date: 1994-02-16
Publication date: 2000-03-29
Anticipated expiration: 2014-02-16
Also published as: FI940718A0; DE59306670D1; CN1092504A; JPH06317235A; KR940019986A; EP0611885B1; FI940718A; EP0611885A1; DK0611885T3; FI106739B; KR100323937B1

Abstract

The fuel injector valve has a valve housing which projects into the combustion chamber of a cylinder of the internal combustion engine and is provided with a seating surface (18) on its end face facing the combustion chamber. Extending through the valve housing is a movable closing piece (20) which is provided at its end facing the combustion chamber, with a mushroom-shaped valve plug (20') projecting from the valve housing and having a sealing surface (19) that interacts with the seating surface (18). The fuel flowing through the valve housing opens the valve, fuel being injected into the combustion chamber under elevated pressure. Arranged on the valve housing is a cap (8) that overlaps the mushroom-shaped valve plug (20') and, in the region of the seating surface (18), has at least one nozzle passage for the formation of a fuel jet.

Description

A kind of fuel injection valve of reciprocating internal combustion engine

The present invention relates to a kind of fuel injection valve of reciprocating internal combustion engine.

This fuel injection valve has a valve chest in the firing chamber of stretching in the cylinder, this valve chest comprises a seal valve seat at its end face near the firing chamber, and but a dynamic seal that extends through this valve chest arranged, the end that the sealing part approaches the firing chamber is provided with the poppet valve core that stretches out and comprises a sealing surfaces that cooperates with the sealing valve seat from valve chest, this spool is opened at the flow direction that fuel oil flows through valve chest, so fuel oil sprays into the firing chamber under the elevated pressure effect.

In this injection valve, seal valve seat and sealing surfaces with matching are used for forming injection when valve is opened, therefore produce a kind of spraying that is similar to taper.One of shortcoming of known fuel injection valve is that Sealing is because its bigger annular opening cross section can only be arranged to little stroke, and its reason is that the Clearance Flow that produces is very responsive between seal valve seat and sealing surfaces.For example, the nonconcentricity that is reached by the sealing part by the tolerance between described this two surface will produce asymmetric spray shapes, and the burning in the firing chamber has adverse effect to fuel oil in this spraying.Another shortcoming is: when the cross section is opened in the jet pressure control that produces by means of Injection Pump, can vibrate when Sealing is opened.In the down periods, these vibrations on Sealing and strain will cause the fracture of poppet valve core in some cases.Then, the spool of this fracture will be fallen in the firing chamber and can produce infringement at piston and/or casing wall place.

The objective of the invention is to improve the injection valve of the above-mentioned type to avoid described shortcoming.

The technical solution of above-mentioned purpose is the fuel injection valve that this reciprocating internal combustion engine is used, has the valve chest in the firing chamber of stretching in the cylinder, near the end face of firing chamber one seal valve seat is arranged at this valve chest, but and has a dynamic seal that passes this valve chest, be provided with a poppet valve core that stretches out and have a sealing surface that cooperates with the sealing valve seat from this valve chest at the sealing part near an end of firing chamber, and this valve is opened at the flow direction that fuel oil flows through this valve chest, wherein, fuel oil sprays into the firing chamber under elevated pressure, the cap that one dress is lived the poppet valve core of sealing part is set at this valve chest place, and in the zone of sealing valve seat, this cap comprises that at least one will form the spray orifice of spraying.

Can guarantee on the spool that by this cap is loaded on the spool that ruptures can not fall in the firing chamber again, and catch by this cap.Therefore can not produce damage at piston and/or casing wall place again.Because therefore this fact will be provided with a spray orifice at least, thereby avoid the taper fuel spray in cap.And produce a fuel spray at least, this spraying have with those comprise link to each other with the front portion of spray orifice and have an identical characteristic of the fuel spray that injection valve produced of the needle-valve of conical seal (contact) face (promptly not having bacterium capitiform spool).The diffusion of spraying in these known standard injection valves has proved success, and also can produce the spraying diffusion by means of the injection valve of the present invention of the spool with bacterium shape capitiform.Another advantage of injection valve of the present invention is, the stroke of Sealing is comparable, and to have a known injection valve of taper fuel spray bigger.Therefore, can change the sectional dimension of the spraying that will form according to the stroke of Sealing, be to regulate the trip by means of the controlling device of jet pressure or Sealing here.

By means of accompanying drawing some embodiments of the present invention are described further below.

Fig. 1 shows the axial sectional view of injection valve of the present invention;

Fig. 2 shows the lower end enlarged view of the injection valve of Fig. 1;

Fig. 3 shows the lower end of comparing the injection valve of improved with Fig. 2;

Fig. 4 shows the injection valve lower end of further improved;

Fig. 5 shows the following end elevation of the injection valve of Fig. 4.

As shown in Figure 1, injection valve comprises a housing 1, and it is made of a upper body 2 and a lower body 3, and this two body is linked together by a lock nut 4.This housing 1 utilizes a flange 5 dress seat on cylinder head 6, the firing chamber 7 of this cylinder head 6 from the cylinder (not looking out) of last reciprocating internal combustion engine adjacent to diesel version.This housing 1 passes cylinder cap 6 and utilizes the part 3 ' of the bottom 3 of diameter minimizing to stretch in the firing chamber 7.

For fuel oil (along arrow A) is supplied with injection valve, this housing 1 comprises an oil transportation channel 10, and it at first fully radially stretches in the flange 5, then basically along housing vertically by upper body 2 and enter lower body 3, it is communicated with in the chamber 11 at this, and this chamber is positioned near the housing center.Be provided with at housing 1 center one can axially movable Sealing 20 bar 12, end (among Fig. 1) has a poppet valve core 20 ' and is withstood by a spring stop 13 in the upper end of sealing part 20 under the sealing part 20, supports a pressure spring 14 in the bottom surface of spring stop.Can lead by axially movable bar 12 in order to give, the lower body of the Lower Half of this upper body 2 comprises a straight-through constant hole 9 of diameter.2 the first half in the upper body, the enlarged diameter in this hole 9 and form one can be with the pilot hole of bar 12 axially movable spring stops 13.By widening also admittance-pressure spring 14 of chamber 15 that the hole forms, and seal by bolt 16 at its top.

The diameter of this bar 12 is located to diminish on chamber 11, thus the thin rod part that forms divide 12 ' and hole 9 between form the annular pass bottom 17 that always extends part 3 '.The edge face structure of this part 3 ' becomes the structure of the cone seal valve seat 18 of firing chamber 7 (Fig. 2) expansion on one day.Sealing valve seat 18 cooperates with corresponding sealing surface 19, and sealing face 19 is formed in the upside of poppet valve core 20 '.

Part 3 ' is screwed on the housing by a nut 8, and part is arranged in firing chamber 7 and spool 20 ' is loaded on wherein under this nut.In the zone of seal valve seat 18, in nut 8, be provided with spray orifice 21 transverse to the longitudinal axis extension of valve, it is used to form fuel injection.Shown in Fig. 2 left side, spray orifice 21 has circular cross section.At the center of nut 8, side is provided with a stop surface 8 ' that upwards lifts within it, and Sealing 20 is resisted against on this stop surface 8 ' when its fully open position.

Fig. 2 also illustrates, within this nut 8 under the side sealing valve seat 18 side also be provided with a cylndrical surface 8 ", it is as the guide surface of sealing part 20, also has a cylindrical structural and sealing surfaces 19 belows on the sealing part 20 are corresponding.The upper bound of this spray orifice 21 is 18 skews of 7 relative seal valve seats towards the firing chamber, and this is because this injection valve has an initial lift of not opening oil spout.

The following work of injection valve as illustrated in fig. 1 and 2: this valve is normally in the closed position, and promptly Sealing 20 tightly is resisted against on the seal valve seat 18 by its sealing surface 19, and this is realized by pressure spring 14.Be full of the fuel oil of pressure in the annular chamber 17 of oil transportation channel 10 less than 100 crust (bar).Fuel oil sprays into the fuel transfer pressure of the Injection Pump (this pump does not mark) that dependence is connected with transport pipe 10 in the firing chamber 7.When the closing pressure of the cracking pressure Overpressure of a safety valve spring 14 that is produced by fuel pressure, the sealing part moves down, so fuel oil energy flow to spray orifice 21 from annular chamber 17.Along with fuel oil flows through spray orifice 21, fuel oil form to spray and atomizing and mixes with pressurized air at this when entering the firing chamber, simultaneously fuel ignition is also burnt.Because borderline phase has to a certain degree biasing to seal valve seat 18 on the spray orifice 21, therefore by lag substantially in spool from seal valve seat the unlatching on 18 of flowing of spray orifice 21.When the fuel transfer pressure of Injection Pump reduced, spool 20 ' was replied closed position by pressure spring 14 effects, sprays end-of-job.The actual journey of Sealing depends on the fuel transfer pressure of Injection Pump and the load of motor.During full load, the sealing part is opened and is resisted against on the stop surface 8 ' until it.

In the embodiment shown in fig. 3, spray orifice 31 has the cross section of substantial rectangular, and seal valve seat 18 7 moves towards the firing chamber relative to the coboundary of spray orifice 31.With respect to the description of the work of injection valve shown in Fig. 1 and 2, therefore should injection work, spool 20 ' will begin in a minute along with lifting from seal valve seat 18.

According to the embodiment shown in the Figure 4 and 5, at the lower end of the rod member 12 ' of Sealing 40, be provided with the poppet valve core 40 ' of a band sealing surface 42 once more, the seal valve seat 18 on the lower end surface of sealing face 42 and part 3 ' cooperates.This spool 40 ' is surrounded by a nut 48.This nut 48 has stop surface and is used for the cylindrical guide surface of Sealing, and its structure is identical with nut 8.Yet one of difference is big than the nut shown in Fig. 38 of the size of rectangle spray orifice 41, and a valve plate 45 that is fixed on below sealing surface 42 on the Sealing 40 stretches in each spray orifice 41.Therefore the upside 45 ' of each valve plate 45 has limited the cross section that forms the spray orifice of spraying in the Figure 4 and 5 in the bottom.The border surface that valve plate 45 is parallel to longitudinal axis leads with sealing means in the adjacent boundary surface of each spray orifice 41.According to the width that each spray orifice 41 circumferencial direction records, nut 48 tops are provided with the slit of same width.Stretch into the arm 43 of a ring 44 in each this slit, this ring surrounds part 3 ' and is arranged on the top edge of nut 48, and can rotate with this nut.Therefore side is adjoining with the cross section of the formation injection of relevant spray orifice 41 thereon in the lower end surface 43 ' of each arm 43 in the Figure 4 and 5.

Identical with described in Fig. 1 and 2 on the working method principle of injection valve shown in the Figure 4 and 5 promptly surpasses when closing the pressure of spring when the fuel transfer pressure of Injection Pump, Sealing 40 direction motion of 7 towards the firing chamber, so fuel oil energy flows out annular space to spray orifice 41.Wherein, the flow cross section of the parts of the injection of the formation in the spray orifice 41 is by the decision of the axial distance between the surface 43 ' and 45 '.

In the embodiment of all explanations, the spray orifice number depends on the application of injection valve.If this injection valve is used for four-cycle diesel, so, center and spray orifice that it is usually located at the firing chamber distribute equably around this injection valve circumference.When this injection valve is used for when its firing chamber center arrangement has the two stroke diesel engine of outlet valve, then have at least several injection valves to be placed in the outside, center.At this moment, each injection valve is furnished with one or more spray orifices, and therefore spray is distributed in the firing chamber in the mode that is beneficial to most burning from their fuel oil.

Different with described embodiment, the also available clamping of nut 8 or 48 connects replacement and is threaded.

Claims

1. fuel injection valve that reciprocating internal combustion engine is used, has the valve chest in the firing chamber of stretching in the cylinder, near the end face of firing chamber one seal valve seat is arranged at this valve chest, but and has a dynamic seal that passes this valve chest, be provided with a poppet valve core that stretches out and have a sealing surface that cooperates with the sealing valve seat from this valve chest at the sealing part near an end of firing chamber, and this valve is opened at the flow direction that fuel oil flows through this valve chest, wherein, fuel oil sprays into the firing chamber under elevated pressure, it is characterized in that, a cap of living the poppet valve core of sealing part is set at this valve chest place, and in the zone of sealing valve seat, this cap comprises that at least one will form the spray orifice of spraying.

2. according to the described valve of claim 1, it is characterized in that: the poppet valve core of described Sealing is by side sealing guiding within this cap.

3. according to claim 1 or 2 described valves, it is characterized in that: the border that deviates from the spray orifice of firing chamber links to each other with the seal valve seat of this valve chest.

4. according to claim 1 or 2 described valves, it is characterized in that: the upper bound that deviates from the spray orifice of firing chamber moves towards the firing chamber with respect to the seal valve seat of this valve chest.

5. according to the described valve of claim 1, it is characterized in that: the sealing surface of circumferential surface is packed in the barrel surface outside the spool, and the control of the edge between sealing face and barrel surface spray orifice import cross-sectional dimension.

6. by the described valve of claim 1, it is characterized in that: to each spray orifice, the poppet valve core of Sealing has the valve plate that stretches into described spray orifice.

7. valve as claimed in claim 1 is characterized in that: constitute a stop surface in the inboard of cap, it has determined the range of sealing part.