DE2350224A1 - PNEUMATIC CONTROL SYSTEM FOR FUEL INJECTION PUMPS - Google Patents

Description

TlEDTKE - SOHUNQ "KlNNE

TEL. (0811) 539653-55 TELEX: 524845 tlpat CABLE ADDRESS: Qermanlapatent Munich.

800 0 Munich 2 Bavarlaring 4 '

P.O. Box 202403 October 5, 1973

Nipponderuso Co., Ltd. Kariya-shi, Japan

Pneumatic control system for fuel injection pumps

The invention relates to a pneumatic control system of the type as provided for a fuel injection pump which supplies fuel for internal combustion engines, particularly diesel engines; such a control system is operated by the vacuum created in the suction line of the engine to control the amount of fuel supplied by the fuel injection pump.

lin general, pneumatic regulators have the above Typically a vacuum chamber for. Inclusion of the in the Intake line of a vacuum created in the internal combustion engine and an atmospheric pressure chamber for receiving under atmospheric pressure, whereby the two chambers are separated from each other by nine diaphragms, which are connected to the control

409817/0335

Deutsche Bank (Munich) Account 51/61070 Dresdner Bank (Munich) Account 3939844 Postscheck (Munich) Account 67043-804

erstange oilier fuel injection pump is connected; included becomes di, e control rod generated by the one in the suction line Vacuum actuated to remove the .injected liquid menpc the To control fuel injection pump.

In this case it is the vacuum created in the suction line the vacuum that formed in dom in part of the suction line Venturi is generated; as is known, this vacuum varies in accordance with the opening of the throttle valve in the venturi and the number of revolutions of the machine. That is why the pneumatic regulators of this type are used to to control the amount of fuel supplied by a fuel injection pui; ipe is delivered to the supply of an optimal amount of liquid, both for the speed as well as the load on the machine (which can generally be assumed to be the opening of the throttle valve corresponds) is suitable to ensure.

\ Ieiin However schnell.vergrößert the opening of the throttle valve to the engine under idle conditions with der'kleinsten opening of the throttle valve or to accelerate rapidly under normal driving conditions with a relatively small opening of the throttle valve, then the vacuum created in the venturi decreases rapidly from _# with the result that the pneumatic leveler operates to rapidly increase the amount of fuel delivered by the fuel injection pump. In this case, this can rapidly increase the opening of the throttle valve

409817/0335

fixed machine itself does not cause the number of its revolutions quickly increase zn. As a result, during rapid acceleration of the machine is unnecessary large amount of fuel is delivered to the engine, resulting in the emission of black puff. The diesel engines makes the emission of such black smoke the greater Part of the impurities, out. Although the emissions that pre-pollute the airspace become a serious social collar have become 'and have become one requiring immediate attention It has become a matter of preventing the emission of such black smoke, so it is for this purpose no effective tax measures have yet been proposed.

The invention is therefore based on the task, a pneumatic one To create a control system for fuel injection pumps, which does not have the disadvantages listed above. at Such a pneumatic control system is a throttle device placed in an inlet line for atmospheric pressure, x at small atmospheric pressure in an atraospheric pressure chamber introduce; at the same time, the inlet pipe becomes the atmospheric pressure during the period of rapid acceleration the engine is throttled in order to prevent the amount of fluid supplied by a fuel injection pump increases rapidly; this avoids the emission of black smoke and helps to keep it clean done in the air. . . .

A major advantage of the pneumatic control system according to

409817/0335

this invention resides in the fact that during the period of rapid acceleration of a machine has a damping effect the atmospheric pressure chamber of the pneumatic regulator exerted , thereby preventing that of a fuel injection pump the amount of liquid delivered can increase rapidly; so that the machine always gets the right amount of fuel supplied, so that the emission of black smoke is completely avoided ', which in the previous devices has been a serious problem.

In the following, the invention will be described using exemplary embodiments with reference to the accompanying schematic drawings

I.
explained in more detail. * Γ

Show it:

Fig. 1 is a schematic representation of a Embodiment of a pneumatic control system for fuel injection pumps according to

of the present invention;

Fig. 2 is a circuit diagram for the main part of the in fl. 1 control system shown; and

Fig. 3 is a diagram used for explanation the operation of the throttle devices used in the system according to Fig..1 can be.

409817 / 0335-

The present invention will now be described in detail and below Described with reference to the illustrated embodiment will" .

Jn i'ig. 1 denotes the reference numeral 1 designates a Ver incineration skraftmaschine (especially a diesel engine), 2 is a Ansauglei tuiig the engine 1, 3 is a formed in a part of the intake passage 2 Vehturi-llohr, k a at the upper end of the venturi UoUrs 3 provided air cleaner \ thereby sucks the engine 1 air through the air cleaner 't, the venturi Rohr 3 "md the intake pipe 2 into the combustion chamber (not shown). A throttle valve 5 is rotatably mounted in the Vonturi tube 3 and, according to its opening, varies the passage area of the Venturi tube 3 in order to control the speed of the air sucked into the combustion chamber of the engine 1. An axis 5a of the throttle valve is connected to an accelerator pedal 8 by a lever 6 and a wire (or rod) 7, so that the opening of the throttle valve corresponds to ¹ the position of the accelerator pedal 8 is changed. The reference number 9 denotes a fuel injection pump which has a cam actuated by the machine 1 and pistons actuated by the cam; these parts are not shown; this pump works in the usual way to inject a fuel into the combustion chamber of the machine 1 * The reference symbol IO denotes a control rod of the fuel injection pump 9i which is engaged with the "piston" (not shown) so that the piston is rotated to from the burning

409817/0335,

fuel injection pump delivered to control fuel quantity, when the control rod 10 in the illustrated example of one side is moved to the other side. Dependent on from their l'Orm, the taxorstarige IO can control the timing control of fuel injection, although they usually do to control 'drr pumped liquid Koi tsiHonge is used.

So far, the structure of the usual Mn se hi no 1 and the fuel injection pump 9 has been explained; The fuel injection pump 9 provided with a pneumatic control system according to this invention will now be described below. In Fig. I 11, reference numeral a pneumatic Hogler with ucm "same structure as a conventional pneumatic * Liegler having a vacuum chamber 13 and an atmospheric pressure Iiainmer 11, the diaphragm 12 connected by a with the control rod IO of the fuel injection pump 9 A compression spring 15 is provided in the vacuum chamber 13 in order to exert a pretension on the membrane 12. Din vacuum chamber 13 stands through a vacuum suction pipe 16 with a venturi pipe formed in the suction line 2 of the machine I. 3 in. Connection, namely according to a preferred embodiment with an auxiliary venturi tube 17 which can be provided in the venturi tube 3. The atmospheric pressure chamber lk is in communication with the atmosphere through an atmospheric ucfc inlet tube 10. The air venturi -Pipe 1? Is of the usual type, and its passage area is constant regardless of the opening of the throttle valve 5 (the passage angular surface

409817/0335

des Venturi-Ho lir ρ 3) · The reference numeral 19 denotes a reads chi euni. <r.unj "s detector to determine the acceleration of the machine, -which in the illustrated Äusführunirsform this Detector the speed of rotation of the throttle valve 5 measures to generate a feedback signal. The draft sign 20 denotes one by the notification signal control unit operated by the acceleration detector 19, to generate a control signal. Numeral 21 denotes one disposed in the atmospheric pressure inlet pipe Throttle device. The throttle device 21 is designed so that it is operated by the control signal from the control unit 20 to the atmospheric pressure inlet pipe 18 for to throttle a period of time depending on the rotational speed of the throttle valve 5 when the rotational speed of the throttle valve 5 exceeds a predetermined value, The throttle unit: 21 is normally open.

Tig. 2 shows an embodiment of the Schaltuiigsauf bans Acceleration detector 19, the control unit 20 and the throttle device 21. The acceleration detector 19 has a potentiometer which is connected to the axis 5 ″ of the in Jig. I. throttle valve 5 shown is connected; the Ürosseleinrichtuiig 21 contains an electromagnetic valve (only the coil this valve is shown). The control unit 20 has a section 20a for the control circuit for generating a the Besclileuniguugssignal from the acceleration detector corresponding control signal, a section 2Ob .. ··

409817/0335

for the actuation circuit of the throttle device for amplification of the control signal to the throttle device 21 to operate, and a voltage regulator circuit 20c on; these individual circuits have the usual structure. The J reference mark 22 denotes a power supply.

With the above construction, the system according to the present invention, the following effects: When the engine 1 is in operation, air is sucked in through the air cleaner ¹ I, the Vcnturi pipe 3 and the intake passage 2 and fuel from the fuel injection pump 9 injected into the combustion chamber. The amount of fuel supplied (injection amount) is controlled by the pneumatic control system according to this invention. This fuel injection amount control is basically carried out in the following manner. According to the speed of the air sucked into the combustion chamber of the engine 1, a vacuum is created in the auxiliary venturi tube 1.7 provided in the venturi tube 3, and this vacuum is introduced into the vacuum chamber 13 of the regulator 11 through the vacuum inlet tube 16. On the other hand, the atmospheric pressure is introduced through the atmospheric pressure inlet pipe into the atmospheric pressure chamber Ik so that the diaphragm 12 is preloaded in accordance with the relationship between the pressure in the vacuum chamber 13, the pressure in the atmospheric pressure chamber Ik and the preload exerted by the compression spring 15 is moved in order to control the amount of fuel delivered by the fuel injection pump 9 with the aid of the control rod 10.

409817/0335

The tyr: iknngswoiso should now iin petiiil according to the operating conditions of the machine ii ie. , in) are described under the general operating conditions and (b) under the condition of rapid acceleration, in), npriiiajle conditions: The specific operating conditions mean that the machine does not have a constant C * psc! iTiindigkei t runs or ^ a (J the Tlasch ^ UP '?? with a slight increase tjesclHeunigt. Under such operating conditions the Jirns.sei device 21 pffen, vltiu daipit the atmospheric pressure in dip Atinqs.p ^ arial pressure jammer 1 ^ 1 of the lip-glers 11 is inserted Since c | he üriick in the AtniQsphärendruck-Kainmer 1 * t resistant;. i§t and the bias exerted by 5% d_er compression spring is also fixed, the l'Ienibran 12 is only nnti'prechend of the variations of the vacuum in {Jer Vakuiiikanimer 13 is actuated. Pa wpiterhiii the Vakiaiini in the YakuurakaiiHijcr ^ .3 corresponds to the opening of the throttle valve 5 (γοη which can in ?? n annelitiien | that it corresponds to the load of the machine 1 ^ -c ^ tj and the number jJer ITiiid.rehungep doi * Masclii ne 1 changes, the ilcglpr IJ £) works on an aliqliche Wpise wjf-e a kpnventionel3-pr nneuniatischer Rpgipr and controls the fuel injection p.uijipp Q, uiii putsprßphen4 the pes.c) "v'Innitude and animal load" of the machine 1 dip pptiniale injected fuel test quantity safe-rzwstellpn. (b, ) Fast acceleration: If the J5rp.ssel "y" entil 5? | wrfc | v d_afs Cjasppdal f} sclmcll is put into a hiclitiing that opens it completely;, lim avif this way the machine 1 sclmell ^: z; n accelerate, then s4.nkt (read 4-ji. the auxiliary venturi-llohr 17 created. Vacuuni schnßlX fib- »so that the membrane 12 in the regulator II tends to move into ßin

To move direction, the fixed amount of liquid supplied by the fuel injection pump Q will quickly increase. In this case, however, the Drosselcinricli tnny; 2 1 actuated by the control signal from the control unit 2O to (las Atmpsphärendruck-Kiiilaßrohr li \ for a period ku throttle corresponding to the rotational speed of the throttle valve. 5 As a result, affect the Atinosphärendruck chamber I ^ as Dampfun-JCS membered " stimulate the rapid movement of the Ileuibran 12 and verMndert that the yQn the fuel injection pump 0 delivered Ilrenns tof f-Einspritznienge rapidly rises This Ablaui "sol · -. be further described ini below with reference to Figure 2, when the throttle valve 1.!. is rotated rapidly, the potential changes rapidly at a point A of the acceleration signal or potentiometer 19 to produce a acceleration signal VA (voltage value). The direct current component of this acceleration signal is removed by a capacitor 23, mn to generate an alternating current signal VB at a point Π. The transistor 2, which is in a non-conductive state 4, this alternating current acceleration signal VB is made conductive, so that the charge stored in a capacitor 25 is passed through a resistor 26, a diode 2? and fJeu transistor 2'l is discharged. As a result, the potential at a point D becomes lower than the potential at which a zener diode 2ii becomes conductive, sq that a conductive transistor "29 is brought into the non-conductive state -

409817/0335

The electromagnetic V on "til 21 is supplied with energy from the energy source 22; it becomes active when the atmospheric pressure pipe is throttled. In this case, the duration of the operation of the electromagnetic valve 21 depends on (Uli, die The period of time during which the atmospheric pressure inlet pipe la is throttled essentially from the time constant, which is determined by a resistor 31 and the capacitor 25; it also changes, as shown in FIG , corresponding to the reduction speed of the potential at the point A. by the potentiometer 1-9 or the rotation speed of the throttle valve 5- In this way, the time during which the atmospheric pressure inlet pipe is throttled by the electromagnetic valve 2.1 becomes corresponding to the acceleration of the machine 1 in order to cause the atmospheric pressure chamber 11 to exert the damping effect already mentioned earlier r transistor 2h placed in the non-conductive state so that the diode 27 is biased in the reverse direction; the capacitor 25 ends its discharge and begins to charge through the resistors J1 and 26. When the potential at point D is higher than the line potential for the Zener diode 2u, then the transistor 29 is brought into the conductive state. The conduction of the transistor 29 makes the transistor 3 ^ non-conductive, so that the electromagnetic valve 21 opens. As a result, the atmospheric pressure inlet pipe IC

409817/0335

not throttled in the least, so that machine 1 runs under the noni'alcu liotr praise conditions. In! '' It · ;. 2 is used a resistor 32 flnzn, the. To adjust the sensitivity of the Tronsi stors 2'i for the Bosch acceleration signal VH generated by the potentiometer 19; The resistor 26 limits the Schwe.1.1 current during the discharge of the capacitor 25.

While in the embodiment described above, the Uesclileimi guiigs-Ue Lektor 19 nls a potentiometer Device has been explained, it can also have a generator, a differential converter oiler or a similar one Element auiVoisen. In a corresponding way, the Control unit 20 may use circuits of different constructions other than that described above Implementation continued.

The invention thus provides a pneumatic system for Rep.el Fuel injection pumps that use a pneumatic reeler a vacuum chamber or negative pressure chamber and an atmospheric pressure chamber also has an electrically operated throttle device, an atmospheric pressure inlet pipe for the entry of atmospheric pressure into the atmospheric pressure chamber, a Control device for actuating the throttle device xmji in Abhfin micke it from the acceleration of the machine and one Accelerated detector for the feeling of fire in the fire Machine and for putting on a Heschlpuniqunnssif »nals to the Tax in rieh do p, ·

409817/0335

Claims (1)

235Ö22'4 M ■ '■■ Γ ft te iit ait S pi-ttc 11 rheumatic control system ΐ'ύν rushed liretihstdrf-Idif Itrit a pneumatic Liegler ¹ Zuh Stfeiieirtiü ^ banks iii teiilfe bt-eHliüiiKskraftiMiiscüiitti elügöspiri-tzifeii lireüHsibiTJTiiierige · wölJ6 ± clrii- piifcühiatiöchfi li ^ * Gici itiit eiiier VaRüüirtkaifiiiibir Aiii · AüfiiäiiHiö iiiiio-a? iii an Änsaiigieitünß: der llasfchiiie ^ i-jsöugtfeit Vfifetiiiiiis iiiid eiliet- ÄtiiioSphHrnrittru: c: kK.amtttt? t · r.iix- AitiiiriHiniR dös Äiiiiöspliäreh- <i ₄ ruck. '; verseiGlt .is, geTteritizcicliiifet by ciiib triit dbr ethib. -. sphärehdriipk-Krthihicr (I ⁷ I) -vrörbtilidene OroSEre-ihiHi-ictitUiig (2l) ^ ri L) .iokselt \ ^r .i.rkuii, n; Ketrtäß öitiem elektfisbltoii signal viiriibrt kaiiti, lind to tjetätigeiij according eirieHi tiüilgssighni by the Drosiseloiririfchtitiig (Ui) vörbtmdeile SteuereitiriclifcülijTGit zttr iirÄetigiiiig DTEs biektrisciiöii iifii .the iJrbsseieiriribiitütig (21) by eiiibii ttiit Deii Öteüereiririciitithgeh V-erbündciieit ileBchietiriigungs-Öctektbr ίί ^ ί 25UR Resisting the TJesbhieuiiigititj ¹ ; rfer machine ^ uitt the neöciileühigüiigssigitnl ?, \ i to generate and give this Deschieuiiiguiig & sigriftl to the direction of the stone. / 409817/0338 Blank page