CN100410524C - Fuel oil injector - Google Patents

Abstract

The present invention relates to a fuel injector which belongs to the technical field of an engine. The present invention comprises a plunger pump device (10), a power device (40) for driving the plunger pump device, and an ejection device (60), wherein the plunger pump device comprises a plunger (11), a pump body (12) and a fuel oil cavity (80); a pressure part (12a) of the pump body is arranged in the fuel oil cavity; the pump body is provided with a pressure cavity (13) for making a plunger moved to and fro and pressing and sending fuel oil; a fuel oil inlet passage (82) and a discharge passage (83) are arranged in the cavity; a fuel oil absorption and overflow passage (81) is arranged between the fuel oil cavity and the pressure cavity; the opening and the closing of the absorption and overflow passage are controlled by the motion of the plunger; the fuel oil enters the fuel oil cavity, one part of the fuel oil and steam are discharged through the discharge passage, and the other part of the fuel oil enters the pressure cavity when the absorption and overflow passage is opened; the fuel oil and one part of the steam are extruded to the fuel oil cavity through the motion of the plunger, and the other part is pressed and sent to the ejection device so as to be ejected. The present invention has simple structure and can cool the pressure cavity of the plunger pump effectively. The present invention can reduce the possibility that the steam enters the pressure cavity, and therefore, the heatproof quality of the fuel injector is improved.

Description

A kind of fuel injector

Technical field

The invention belongs to technical field of engines, be specifically related to the electronic oil injection device, relate in particular to a kind of electronic fuel injection system that is applied in internal-combustion engine.

Background technique

Existing BOSCH electronic fuel injection system provides fuel oil by the rotating electromagnetic pump that is embedded in the fuel tank, and fuel oil arrives nozzle by high-pressure oil passage and after pressure regulation, and electronic control unit (ECU) control nozzle quantitatively periodically sprays into intake manifold with fuel oil.When this system was used in small displacement engine, for example can there be problems such as cost height, poor stability and suction pressure fluctuation influence are big in motorcycle engine, for the in-cylinder direct injection combustion system, satisfies higher fuel-injection pressure and also has very big difficulty.

Chinese invention patent ZL01103954.X " electronic fuel oil jetter " provides a kind of fuel injection apparatus of novel pulsed Electromagnetic Drive, form by fuel inletting device, fuel-powered device and fuel ejecting device, actuating coil and returning coil by fuel-powered device form the driven device that the magnetic loop driving comprises armature and plunger, realize the reciprocation cycle of oil suction oil spout.The integrated type oil supplying unit that this invention provides can directly be obtained fuel oil by low pressure fuel pipe from fuel tank, and can obtain higher fuel-injection pressure, not only can realize intake port injection, can also satisfy the requirement of in-cylinder direct injection.

This fuel injection apparatus may run into following problem on using: under the situations such as the engine long time shelves, hot car state starts, long-time idling and the big load of high temperature travel, the inside and outside fuel gallery of injection apparatus is easy to generate and accumulates fuel-steam, thereby influences proper functioning.

The prior art structure all realizes the fuel oil force feed by plunger pump, and plunger pump certainly exists the pressure chamber of a force feed fuel oil, in case occur steam in the pressure chamber, fuel oil can not get effective force feed, also just can't spray.The structure that above-mentioned patent proposed is comparatively complicated, and how effectively not to be particularly related to cooling pressure chamber volume, prevents that fuel-steam from entering the problem of pressure chamber.In order to realize higher heatproof standard, need to propose new scheme with simpler structure.

Summary of the invention

The present invention is directed to existing problem, purpose be to provide a kind of simple in structure, can effectively cool off plunger pumping pressure chamber, and reduce the possibility that fuel-steam enters pressure chamber, thereby improve the heat resistance of fuel injector.

Purpose of the present invention is achieved through the following technical solutions:

It is a kind of fuel injector, it comprises: a plunger pump device, the power plant of a drive plunger pump motion, an injecting device, it is characterized in that: described plunger pump device comprises a plunger, a pump housing, a fuel chamber, pump housing pressure is deployed among fuel chamber, the pump housing is provided with the pressure chamber for plunger to-and-fro motion and force feed fuel oil, fuel chamber is provided with fuel oil inlet passage and a discharge route that is positioned at its top, between fuel chamber and pressure chamber, be provided with fuel oil and inhale the passage that overflows, inhaling the switch of the passage that overflows is controlled by plunger motion, fuel oil enters fuel chamber through the fuel gallery, and a part of fuel oil and steam thereof are discharged by discharge route, and another part fuel oil overflows in suction and enters pressure chamber when passage is opened, fuel oil (and steam) part that enters in the pressure chamber is extruded and gets back to fuel chamber via inhaling the passage that overflows because of the motion of plunger, and another part then is pressed to injection apparatus and sprays.

Pressure chamber forms P-V with the border of plunger, and the pump housing that comprises P-V partly is pump housing pressure portion.Fuel chamber is a space with a constant volume, and fuel chamber can hold enough fuel oils with the P-V among the cooling pump housing pressure portion.

One end of plunger gos deep in the pressure chamber, and the other end is accepted the driving of power plant outside pressure chamber.The return of plunger can rely on the combination of spring force or electromagnetic force or spring force and electromagnetic force, and spring can be located among the pressure chamber, acts on the front end of plunger, also can be located at outside the pressure chamber, acts on an other end of plunger.

Directly enter the excessive passage of suction for fear of the fuel-steam from inlet passage, inlet passage is arranged on as far as possible away from the position of inhaling the passage that overflows.

Injecting device comprises outlet valve and nozzle.Outlet valve is an one-way valve, is used to stop the fuel oil refluence back pressure power volume that enters nozzle; Nozzle can be a nozzle that relies on pressure outwards to open, and the outside of nozzle valve seat can exist a flow guide device to change injection direction, and flow guide device has a remaining volume and spray orifice, and fuel oil enters remaining volume by valve seat, sprays through nozzle again.Outlet valve comprises fuel-displaced valve body, delivery valve seat, outlet valve ectosome and oil outlet valve spring, wherein the shape of fuel-displaced valve body can be a thin slice, delivery valve seat can be provided with elastic material to strengthen the sealing of outlet valve, and oil outlet valve spring acts between outlet valve ectosome and the fuel-displaced valve body.

Described power plant can be mechanical devices that reciprocating power can be provided, and for example cam mechanism also can be the calutron of a helix tubular type.

Described calutron comprises coil, armature, armature chamber and magnetic gap, and armature moves in armature chamber under the driving of the electromagnetic force that described coil forms, and the top of armature chamber is provided with drainback passage, and fuel oil and steam thereof in the armature chamber are discharged through drainback passage.

The excessive passage of described suction can be one or more simple circular hole, also can be the ring-type oil duct with square-section.One end of the excessive passage of at this moment described suction is located on the hydraulically smooth surface of pressure chamber, plunger and hydraulically smooth surface are formed fastness, keep little between them and gap that sliding is good with the fuel pressure in the build-up pressure chamber, when plunger is closed in the force feed movement process when inhale overflowing passage, plunger and pressure chamber form the space of a relative closure, plunger begins to push fuel oil, and when plunger open to inhale overflow passage once more in the returning movement process, fuel oil was inhaled into pressure chamber because of the degree of vacuum in the pressure chamber.

In order to make the fuel oil in the P-V have lower temperature, the pump housing pressure portion that surrounds P-V need obtain good cooling, and this part pump housing is placed among the fuel chamber, can reach this purpose.Fuel chamber can be a cylinder type space with a constant volume, after the pump housing is inserted, they form an annular space that is full of fuel oil, also can form several little spaces that are interconnected, these space distributions are around the pump housing, and even fuel oil wherein can cool off pump housing P-V, and fuel-steam can in time be discharged by discharge route.

Discharge route can directly be connected with the oil-way system outside the sparger, also can be connected with oil-way system outside the sparger by armature chamber and drainback passage.Discharge route leads to armature chamber in the top of fuel chamber is provided with, and enters the fuel oil of armature chamber and the heat that steam can further be taken away armature chamber thereof, and discharges by drainback passage.Also have a scheme that helps arranging to be, discharge route is along the axis of armature, and between coil and armature, perhaps arrange between coil and the shell, converge and shared same outlet is connected with oil circuit outside the oil sprayer at the outlet port and the drainback passage of passage.

Plunger can be roughly cylindrical body, the one end can be provided with the annular boss of ammunition feed spring effect, another end face is positioned to be inhaled near the passage that overflows, and the determining positions of end face is inhaled the on off state of the passage that overflows, promptly, in plunger force feed stroke, end face is inhaled the passage that overflows and is covered by the seal side of plunger through after inhaling the passage that overflows, and the oil circuit that therefore leads to P-V is cut off, otherwise oil circuit is open-minded.

Inhale the integrity problem that the channel switch that overflows may bring for fear of end face control, plunger is provided with one and goes up annular groove, last annular groove remains with P-V by plunger channel and is communicated with, last annular groove is positioned to be inhaled near the passage that overflows. and the upper edge determining positions of using annular groove is inhaled the Push And Release of the passage that overflows, and it is similar that principle and the plunger end face of inhaling the channel switch that overflows are controlled in the upper edge of last annular groove.

A kind of better scheme that helps avoiding steam to disturb is: also be provided with one and inhale the passage that overflows down near the plunger end face, the excessive passage of following suction connects fuel chamber and pressure chamber, inhales the Push And Release of the passage that overflows under the determining positions of plunger end face.Excessive the opening with close moment of passage of excessive passage of following suction and last suction can keep synchronously, also can be asynchronous.

The same reason with establishing annular groove, the plunger channel that also is provided with a following annular groove on the plunger and is communicated with P-V, also be provided with an excessive passage of suction down near the annular groove down, the excessive passage of following suction connects fuel chamber and pressure chamber, inhales the Push And Release of excessive passage under the upper edge determining positions of following annular groove.

The ejection oil duct that leads to injecting device is positioned within the scope of annular groove, and P-V remains with the ejection oil duct and is communicated with.The ejection oil duct can be positioned at the annular groove scope, does not influence fuel oil and enters injecting device to such an extent as to also can be positioned at the motion of other P-V district plunger.

The axis of injection apparatus can be parallel with the motion of plunger, also can be vertical, and installation can also have a certain degree.The sort of mounting type no matter, injecting device all will pass the wall of fuel chamber and lead to the outside, and fuel leakage in order to prevent to pass wall can be provided with sealing material between the ectosome of injecting device and fuel chamber wall, for example rubber etc.

Armature axially can be provided with the armature fuel gallery at it, also can have the side oil duct at the wall of armature chamber and form resistance to avoid fuel oil for armature movement.In addition, the oil duct of armature also has the pump functional oil, and when the circulation area of the ingress of armature fuel gallery during greater than the circulation area in outlet port, this pump oil effect is fairly obvious.

In above-mentioned all schemes, can between fuel chamber and P-V, establish an oil sucting one-way valve, the inlet of this one-way valve is positioned at fuel chamber one end, thereby can reduce the resistance of plunger motion, strengthens the oil suction effect.Described oil sucting one-way valve comprises the oil suction valve body, and oil suction valve seat and Returnning spring, oil suction valve body can be steel balls.

Above-mentioned all relate in the scheme of electromagnetic motive device of solenoid type, in order to accelerate the speed of armature and plunger rollback, except the rollback spring is set, can increase a coil and corresponding magnetic circuit, described magnetic circuit comprises yoke and magnetic gap.This two coil configuration can improve the frequency of okperation and the jet pressure of described fuel injector effectively.

Description of drawings

Below in conjunction with the drawings and specific embodiments the present invention is done and to describe in further detail:

Fig. 1 is first embodiment's of a fuel injector provided by the invention structural representation.

Fig. 2 is second embodiment's of a fuel injector provided by the invention structural representation.

Fig. 3 is the 3rd embodiment's of a fuel injector provided by the invention structural representation.

Fig. 4 is applied to the pie graph of engine fuel system for one embodiment of the invention.

Embodiment

As shown in Figure 1, in first embodiment, fuel injector of the present invention comprises: 40, one injecting devices 60 of power plant of 10, one drive plunger pump motions of a plunger pump device.

Plunger pump device 10 comprises 12, one fuel chambers 80 of 11, one pump housings of a plunger.

Plunger 11 is roughly cylindrical body, the pump housing 12 is provided with the pressure chamber 13 for plunger to-and-fro motion and force feed fuel oil, pressure chamber 13 is spaces of an opening, it has an inlet that supplies plunger 11 to enter, the space that wall constitutes within interface of plunger 11 (for example end face) and the pressure chamber 13 is P-V 13a, the wall of pressure chamber 13 comprises the part hydraulically smooth surface 17 similar to the outer plunger surface shape at least, plunger 11 is formed fastness with hydraulically smooth surface 17, keep little between them and gap that sliding is good, thereby when plunger stretches to pressure chamber's 13 motions, P-V 13a reduces, and fuel oil wherein is extruded, and this process is the force feed process; When plunger 11 during from pressure chamber 13 rollbacks, P-V 13a increases, and fuel pressure wherein also can reduce thereupon, and negative pressure occurs, and this process is a back off procedure.

Between fuel chamber 80 and P-V 13a, be provided with two passages that can supply fuel oil/steam exchange: inhale and overflow passage 81 and inhale the passage 81a that overflows down, their ends all are located on the hydraulically smooth surface of pressure chamber 13 respectively, they open and close the control of receiving plunger 11 motion, inhale when the smooth side surface coverage of plunger 11 and to overflow passage 81 and to inhale the passage 81a one that overflows down when bringing out mouthful, then they are closed, otherwise they are in opening state.

Plunger 11 is provided with a plunger channel 14 of going up annular groove 15 and a following annular groove 16 and their connection P-V 13a.Last annular groove 15 is positioned to be inhaled near the passage 81 that overflows, and in the force feed process, when the upper edge of last annular groove 15 15a overflow passage 81 by suction fully, this passage was closed, and in back off procedure, when the upper edge of last annular groove 15 15a overflow passage 81 through inhaling, this passage was by open-minded; Following annular groove 16 is positioned to be inhaled down near the passage 81a that overflows, and the on off state of the passage 81a that overflows is inhaled in position, the upper edge 16a decision of following annular groove 16 down.

When the excessive passage 81 of suction was fully closed with the excessive passage 81a of following suction, the fuel oil among the P-V 13a just was squeezed, and is pressed to injecting device 60 then, finished the oily process of pump of plunger pump device 10.When the passage 81 or inhale down of inhale overflowing overflow passage 81a one of them when opening, fuel oil enters P-V 13a from fuel chamber 80, realizes the oil-absorbing process of plunger pump device 10.In inhaling overflow passage 81 and following force feed process of inhaling before the passage 81a that overflows is fully closed, fuel-steam in the pressure chamber and part fuel oil at first are extruded the oil pocket 80 that strile-backs, thereby have removed the steam among the P-V 13a, have guaranteed the precision of fuel feeding.

Fuel chamber 80 is near cylindrical spaces, is provided with a discharge route 83 on the top in its space and is used in time getting rid of steam in this space.Fuel oil enters fuel chamber 80 by an inlet passage 82.Fuel oil can perhaps arrive inlet passage 82 by an oil feed pump directly from fuel tank or a vapor-liquid separating device; Can directly get back to fuel tank or enter a vapor-liquid separating device from fuel oil and fuel-steam that discharge route 83 is discharged.

Fuel chamber 80 has enough big volume holding fuel oil, thereby the pump housing pressure 12a of portion obtains cooling among then placing the fuel oil of fuel chamber 80.The pump housing pressure 12a of portion comprises P-V 13a, and therefore fuel oil wherein also is subjected to cooling off to reduce the generation of fuel-steam simultaneously.The space of fuel chamber 80 is surrounded by the oil pocket housing 85 and the pump housing 12, is full of fuel oil and a spot of fuel-steam during work.Oil pocket housing 85 can be made by metal or nonmetallic material, and fuel chamber 80 can be a complete space, also can be made up of several little spaces that is interconnected.

Power plant 40 are calutrons of a solenoid type, it comprises coil 47, armature 41, armature chamber 42, external magnetic circuit 45, magnetic conduction sleeve 46 and magnetic gap 44, and wherein external magnetic circuit 45, magnetic conduction sleeve 46, armature 41 and magnetic gap 44 have constituted the closed magnetic path of a calutron.Armature 41 motion in armature chamber 42 under the driving of the electromagnetic force that described coil 47 forms, the top of armature chamber 42 is provided with drainback passage 48, and fuel oil in the armature chamber 42 and steam thereof are discharged through drainback passage 48.

Coil 47 is the spiraltrons that formed by common conductive material (for example enameled cable) coiling.

Armature 41 is roughly a cylindrical body, is made by soft magnetic material.Armature 41 comprises the armature oil duct 43 that connects front/rear end, and armature oil duct 43 can be established one by its center, also can along circumferential arrangement several.The circulation area of the front end 43a of armature oil duct helps fuel oil like this and flows to drainback passage 48 and discharge fuel-steam greater than the circulation area of armature oil duct rear end 43b.

Armature 41 moves reciprocatingly in armature chamber 42, and armature chamber 42 is spaces of being delimited by magnetic conduction sleeve 46 and magnetic gap 44, rear end cover 49, plunges pump body 12.Armature chamber 42 is beneficial to it and carries out linear reciprocating motion being complementary with the profile of armature 41 in shape.

Magnetic gap 44 is filled by non-magnet material, for example, and stainless steel, copper, plastics or even fuel oil or fills with air.

Armature 41 front ends are provided with a supporting element 41a, and supporting element 41a and plunger can be connected as a single entity, and also can be two separate piece that abut against together.The purpose that supporting element 41a is set is electromagnetic force is passed to plunger 11, guarantees that simultaneously there is enough big circulation area at the front end 43a place of armature oil duct, therefore, in supporting element 41a arranged around lateral channel 43c is arranged.

At the initial position of armature 41 motions, the forward position 41b of armature is positioned among the magnetic gap 44, and after coil 47 passed through electric current, the magnetic force of generation was pushed ahead armature 41, thereby promotes plunger 11 to carry out its force feed process.

Plunger 11 is provided with an annular boss 11a for return spring 18 effects near the end of supporting element 41a, and return spring 18 acts between the plunger 11 and the pump housing 12, for the rollback of plunger 11 and armature 41 provides returning place force.

Discharge route 83a leads to armature chamber 42 in the top of fuel chamber 80 also is provided with.Interior discharge route 83a can exist simultaneously with discharge route 83, also can replace discharge route 83 fully.

Injecting device 60 comprises outlet valve 90 and nozzle 60a.

Outlet valve 90 comprises fuel-displaced valve body 91, delivery valve seat 92, fuel-displaced spring 93 and outlet valve ectosome 95, and it mainly acts on is the fuel pressure that keeps in the injecting device, prevents that fuel flow returns is in P-V 13a.In off position good sealing property will be arranged between delivery valve seat 92 and the fuel-displaced valve body 91, delivery valve seat 92 can contain the good sealing performance material, for example rubber etc.; Fuel-displaced valve body 91 can a thin slice, also can be cone or spheroid.Fuel-displaced spring 93 acts between fuel-displaced valve body 91 and the outlet valve ectosome 95.

Nozzle 60a comprises nozzle valve rod 65, valve seat 66, nozzle spring 62, nozzle ectosome 22, air guide sleeve 61 and spray orifice 68.Valve rod 65 1 ends are provided with spring seat 65a, and the other end is valve rod conical surface 65b; Valve seat 66 is provided with oil inlet hole 69 and valve seat seat surface 66b; Nozzle spring 62 acts between spring seat 65a and the valve seat 66.Nozzle ectosome 22 forms nozzle chamber 64 with valve seat 66, and nozzle ectosome 22 is provided with the oiler 21 that enters nozzle chamber; Air guide sleeve 61 forms remaining volume 67 with valve seat 66.

Wall at pressure chamber 13 is provided with an ejection oil duct 19 that leads to injecting device inlet 24, and ejection oil duct 19 is positioned near the annular groove 15, makes P-V 13a and injecting device inlet 94 remain connected state.The fuel oil that is squeezed among the P-V 13a arrives nozzle oiler 21 by ejection oil duct 19, injecting device inlet 24, delivery valve seat 92.

High pressure fuel from outlet valve 90 enters nozzle chamber 64 from oiler 21, arrive the sealed seat surface 65b/66b of valve again from oil inlet hole 69, after fuel pressure is higher than institute's definite value, valve rod seat surface 65b overcomes nozzle spring 62 under the effect of fuel pressure the active force seat surface 66b that lifts off a seat, fuel oil passes through to arrive remaining volume 67 behind the nozzle group valve, and through spray orifice 68 ejections.After fuel pressure was reduced to institute's definite value, valve rod seat surface 65b got back to valve seat seat surface 66b once more under the effect of nozzle spring 62, nozzle group valve cuts out.In nozzle chamber 64, may be provided with fuel strainer and pass through the fuel oil of oil inlet hole 69 in order to avoid influence nozzle operation with filtration.

Also be provided with an oil sucting one-way valve 70 from fuel chamber 80 to P-V 13a.

Oil sucting one-way valve 70 comprises oil suction valve body 71, oil suction valve seat 73 and Returnning spring 72.When plunger 11 beginning rollbacks, the fuel pressure in the P-V 13a is lower than the fuel pressure in the fuel chamber, and oil suction valve body 71 overcomes spring force and opens under the effect of this pressure reduction, and fuel oil enters among the P-V 13a by this valve.

Can not influence its fundamental function after said apparatus done following simplification, but might influence other index: cancellation oil sucting one-way valve 70; Overflow passage 81a and following annular groove 16 are inhaled in cancellation down.

The axis of the present invention's injecting device 60 can be vertical with the moving direction of plunger 11, also can become some angles to adapt to different mounting types.The axis of injecting device 60 also can be parallel with the moving direction of plunger 11, and at this moment, injecting device 60 will be located at the place ahead of plunger 11 moving direction.The wall 85 that no matter the sort of design, injecting device 60 all will be passed fuel chamber 80 stretches to the outside, is provided with sealing material 23 between the ectosome of injecting device 60 and the wall 85 to prevent the leakage of fuel oil, and sealing material can be a rubber o-ring etc.

Below be the working procedure of fuel injector provided by the invention:

At each circuit initial time, the front-end face 41b of armature 41 is positioned within the length of magnetic gap 44 of non-magnetic conduction, coil 47 travels forward to drive armature 41 by the voltage wave formation pulsed magnet field of input, armature 41 moves down by supporting element 41a roof pressure plunger 11, spring 18 is compressed, the force feed stroke of beginning fuel.

In the starting stage of pressurization, P-V 13a is communicated with by inhaling to overflow passage 81 and inhale the passage 81a that overflows down with fuel chamber 80, part of fuel among the P-V 13a and the fuel-steam that may exist are extruded in the fuel chamber 80, and the fuel-steam in the fuel chamber 80 excretes by discharge route 83 and (perhaps) interior discharge route 83a.

Plunger 41 continues descending, (perhaps successively) closed to inhale and overflow passage 81 and inhale the passage 81a that overflows down simultaneously, fuel oil among the P-V 13a is extruded at this moment, when wherein fuel oil is raised to setting pressure, outlet valve 90 is opened, fuel oil among the P-V 13a enters nozzle chambers 64 through outlet valve 90, when fuel pressure is higher than the pretightening force of nozzle spring 62, valve rod 65 ejects outwardly, fuel oil enters nozzle seat surface 65b/66b by the oil inlet hole on the nozzle body 66 69, and fuel oil enters remaining volume 67 thereupon and sprayed by spray orifice 68.When the active force that produces for valve rod 65 when the oil pressure in the nozzle chamber 64 was lower than the active force of spring 69, valve rod 65 began to take a seat, and nozzle is closed.

Back fuel oil end injection is closed in the energising of coil 47, and plunger 41 is done the rollback motion under the effect of return spring 18, carries out the attraction stroke of fuel simultaneously.Fresh fuel oil at first enters P-V 13a through oil sucting one-way valve 70 from fuel chamber 80, and when inhale overflowing passage 81 or/and when inhaling the passage 81a that overflows down and opening, more fuel oil enters P-V 13a through them again, and armature 41 is got back to initial position at last.In above-mentioned circulation, the fuel oil among the P-V 13a obtains fuel cools in the fuel chamber 80 all the time by the pump housing pressure 12a of portion, has avoided the generation of a large amount of steam.The front-end face of armature 21 is also got back within the length of magnetic gap 28, prepares next circulation of beginning.

As shown in Figure 2, in second embodiment provided by the invention,

The plunger pump structure has been done further simplification on first embodiment's basis.On the hydraulically smooth surface 111 of an approximate cylindrical pressure chamber 105, be furnished with the excessive path 10 2 of the suction of leading to fuel chamber 107, inhale the passage that overflows and to have only one or more, be arranged near the plunger end face 110 of plunger 104, inhale the on off state of the path 10 2 that overflows and determine by the position of end face 110.Plunger end face 110 in the present embodiment aspect the switch of path 10 2 that realize to inhale overflows, replaced fully among first embodiment on the effect of annular groove upper edge 15a.

Compare with first embodiment, the fuel oil exchange between P-V 105a (13a) and the fuel chamber 107 (80) is only finished by inhaling the path 10 2 that overflows, and has cancelled oil sucting one-way valve 70; In addition, also cancelled plunger channel 14 among first embodiment.

Fuel chamber 107 is provided with a fuel oil inlet passage 101 and an interior discharge route 108, and interior discharge route 108 is located at the top of fuel chamber 107 and remains connected state with armature chamber 109, thereby the steam in the assurance fuel chamber 107 can in time be discharged.

Compare with first embodiment, 107 of fuel chambers pass through interior discharge route 108 and get rid of steam, and have cancelled discharge route 83.

The side oil duct 106 that leads to injecting device is arranged on the sidewall of P-V 105a, to guarantee that P-V 105a and injecting device inlet 112 is in connected state in the whole motion process of plunger.

At each circuit initial time, plunger end face 110 is positioned to be inhaled near the path 10 2 that overflows, and make them be in opening state, beginning along with the force feed process, P-V 105a dwindles gradually, in the early stage, inhales the path 10 2 that overflows and still keeps connected state with P-V 105a, fuel-steam wherein and part fuel oil at first are extruded the oil pocket 107 that strile-backs, thereby have removed the steam among the P-V 105a.After plunger end face 110 is fully by the path 10 2 that inhale to overflow, the outlet covering of the path 10 2 that overflows will be inhaled in the smooth side of plunger 104, and the fuel oil among the P-V 105a just is squeezed, and be pressed to injecting device 60 then and spray; After end of injection, plunger begins rollback, when plunger end face 110 overflows path 10 2 through inhaling, they are once more by open-minded, because the fuel pressure in the P-V 105a will be lower than the pressure in the fuel chamber 107, fuel oil in the fuel chamber 107 enters P-V 105a by inhaling oil spilling road 102, thereby finishes the oil-absorbing process of plunger pump.

The excessive path 10 2 of the suction of present embodiment can have more than one or one, another inhale to overflow path 10 3 radially with inhale the path 10 2 angled layouts of overflowing, it also can be different with the excessive path 10 2 of suction at axial high and low position, so more to help the discharge of fuel-steam.

Other is with embodiment 1.

As shown in Figure 3, oil supply unit provided by the invention is in the 3rd embodiment

In the present embodiment, injecting device 215 main axiss are consistent with the moving direction of plunger 218, are installed in the front end of the moving direction of plunger 218, and pressure chamber 205a is provided with ejection oil duct 206, and it is communicated with the inlet 220 of injecting device.

Fuel chamber 203 is provided with a fuel oil inlet passage 201 and an interior discharge route 202, and interior discharge route 202 is located at the top of fuel chamber 203, and keeps being communicated with armature chamber 216, and the fuel-steam in the fuel chamber 203 is in time discharged.Between fuel chamber 203 and pressure chamber 205, be provided with and inhale the passage 204 that overflows, the outlet of inhaling the passage 204 that overflows is located on the hydraulically smooth surface 221 of pressure chamber 205, to such an extent as to the motion of plunger 218 can be controlled the switch of the passage 204 that inhale to overflow, the on off state of inhaling the passage 204 that overflows is still by the determining positions of plunger end face 219.

Fuel chamber 203 also is provided with a discharge route 202a, and it is in parallel with interior discharge route 202, between armature 250 and coil 252.The inlet of discharge route is located among the fuel chamber 203, and outlet is connected with drainback passage 251.

The applied injecting device 230 of present embodiment comprises fuel-displaced 215 and outward opening axonometer nozzle 230a.Outlet valve 215 is identical with outlet valve 90 among first embodiment.

Outward opening axonometer nozzle 230a comprises nozzle valve rod 210, nozzle valve seat 207 and nozzle spring 212.Jet stem 210 1 ends are provided with nozzle springs seat 210a and valve rod seat surface 208, and nozzle valve seat 207 comprises nozzle valve seat seat surface 209 and oil inlet hole 213.

After fuel oil enters nozzle chamber 214, arrive the sealed seat surface 208/209 of nozzle group valve again from oil inlet hole 213, after fuel pressure is higher than institute's definite value, valve rod seat surface 208 overcomes nozzle spring 212 under the effect of fuel pressure the active force seat surface 209 of lifting off a seat, fuel oil directly sprays by sealed nozzle seat surface 208/209.After fuel pressure was reduced to institute's definite value, valve rod seat surface 208 was got back to valve seat seat surface 209 once more under the effect of nozzle spring 212, nozzle group valve cuts out.

Other is with embodiment 2

As shown in Figure 4, the practical application of the present invention's fuel injector on motor for example

Fuel oil is entered the cavity 7a of vapor-liquid separator 7 through filter screen 4a, fuel tap 10 and filtrating equipment 4 by fuel tank 6, wherein but filtrating equipment 4 is an Option stage, another selectable path is standby oily path, it is to enter fuel tap 10 by reserve filter 4b, when fuel level 6a is lower than the inlet of filter 4a, fuel tap 10 is just opened, and standby oil circuit just can work, and fuel tap 10 can be closed the two-way fuel oil fully.Fuel oil in the cavity 7a arrives the fuel oil inlet passage 11 of the present invention's fuel injector 1 through oil inlet pipe 3, part fuel oil sprays into the intake duct (perhaps cylinder) of motor 2 through injection apparatus 60, remaining part is discharged from drainback passage 12, gets back to the cavity 7a of vapor-liquid separator 7 through return tube 5.

Fuel-steam in the present invention's the integrated type oil supplying unit 1 takes to the cavity 7a of vapor-liquid separator 7 from drainback passage, by gas exhaust piping 8 fuel-steam wherein is discharged on the liquid level 6a of fuel tank 6 again, the inlet of gas exhaust piping 8 on cavity 7a, outlet remain on the liquid level 6a or near.

Claims (13)

1. fuel injector, it comprises: a plunger pump device (10), the power plant (40) of a drive plunger pump motion, an injecting device (60), it is characterized in that: described plunger pump device (10) comprises a plunger (11), a pump housing (12), a fuel chamber (80), pump housing pressure portion (12a) places among the fuel chamber (80), the pump housing (12) is provided with the pressure chamber (13) for plunger to-and-fro motion and force feed fuel oil, fuel chamber (80) is provided with fuel oil inlet passage (82) and a discharge route (83) that is positioned at fuel chamber (80) top, between fuel chamber (80) and pressure chamber (13), be provided with fuel oil and inhale the passage (81) that overflows, inhaling the switch of the passage (81) that overflows is controlled by plunger (11) motion, fuel oil enters fuel chamber (80) through fuel oil inlet passage (82), part fuel oil and steam thereof are discharged by discharge route (83), another part fuel oil overflows in suction and enters pressure chamber (13) when passage (81) is opened, enter a fuel oil in the pressure chamber (13) and a steam part thereof and be extruded and get back to fuel chamber (80) via inhaling the passage that overflows because of the motion of plunger (11), another part then is pressed to injecting device (60) and sprays.

2. fuel injector as claimed in claim 1, it is characterized in that: power plant (40) are the calutrons of a solenoid type, it comprises coil (47), armature (41), armature chamber (42) and magnetic gap (44), armature (41) is motion in armature chamber (42) under the driving of the electromagnetic force that described coil (47) forms, the top of armature chamber (42) is provided with drainback passage (48), and fuel oil in the armature chamber (42) and steam thereof are discharged through drainback passage (48).

3. fuel injector as claimed in claim 2 is characterized in that, injecting device (60) comprises outlet valve (90) and nozzle (60a), and outlet valve (90) comprises fuel-displaced valve body (91), delivery valve seat (92) and oil outlet valve spring (93).

4. fuel injector as claimed in claim 3, it is characterized in that: an overflow end of passage (81) of described suction is located on the hydraulically smooth surface (17) of pressure chamber (13), plunger (11) is formed fastness with hydraulically smooth surface (17), keep little between them and gap that sliding is good with the fuel pressure in build-up pressure chamber (13), when plunger (11) is closed in the force feed movement process when inhale overflowing passage (81), plunger (11) begins to push fuel oil, when plunger (11) open to inhale overflow passage (81) once more in the returning movement process, fuel oil was inhaled into pressure chamber (13).

5. fuel injector as claimed in claim 4 is characterized in that: be provided with the interior discharge route (83a) that leads to armature chamber (42) on the top of fuel chamber (80).

6. fuel injector as claimed in claim 5 is characterized in that: the end face (11b) of plunger (11) is positioned to be inhaled near the passage (81) that overflows, and the determining positions of end face (11b) is inhaled the on off state of the passage (81) that overflows.

7. fuel injector as claimed in claim 5, it is characterized in that: plunger (11) is roughly cylindrical body, cylindrical body is provided with the plunger channel (14) going up annular groove (15) and be communicated with P-V (13a), last annular groove (15) is positioned to be inhaled near the passage (81) that overflows, and the determining positions of the upper edge (15a) of last annular groove (15) is inhaled the on off state of the passage (81) that overflows.

8. fuel injector as claimed in claim 7, it is characterized in that: near plunger end face (11b), also be provided with one and inhale the passage (81a) that overflows down, the excessive passage (81a) of following suction connects fuel chamber (80) and pressure chamber (13), inhales the on off state of the passage (81a) that overflows under the determining positions of plunger end face (11b).

9. fuel injector as claimed in claim 7, it is characterized in that: also be provided with a following annular groove (16) on the plunger (11), also be provided with an excessive passage (81a) of suction down near the annular groove (16) down, the excessive passage (81a) of following suction connects fuel chamber (80) and pressure chamber (13), and the on off state of excessive passage (81a) is inhaled in position, upper edge (16a) decision of following annular groove (16) down.

10. as one of claim 7-9 described fuel injector, it is characterized in that: the ejection oil duct (19) that leads to injecting device (60) is positioned within the scope of annular groove (15), and P-V (13a) remains with ejection oil duct (19) and is communicated with.

11. as one of claim 2-9 described fuel injector, it is characterized in that: be axially arranged with armature fuel gallery (43) along armature (41) is reciprocating, the circulation area that the circulation area that the inlet (43a) of armature fuel gallery (43) is located is located greater than outlet (43b).

12., it is characterized in that: also be provided with an oil sucting one-way valve (70) to P-V (13a) from fuel chamber (80) as one of claim 1-9 described fuel injector.

13. as one of claim 2-9 described fuel injector, it is characterized in that power plant (40) comprise two coils and magnetic gap, one of them coil and magnetic gap are used to promote plunger pump device (10) force feed fuel oil, and another coil and magnetic gap then are used for the return of armature (41) and plunger (11).

Images