DE2343243A1 - FUEL INJECTION PUMP FOR COMBUSTION ENGINES - Google Patents

Description

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PATESTAXWALIE DIPL.-IXG. C. STOEPEL · DIPL.-I> G. VT GOf L »V ^T JTZER · DIPL.-ING. FW MOLL

674 LAXDAU / PALATINATE AM SCIIÜTZENHOF

TEL. 00341 / 3000,0035 TELEX 4S3333

August 27, 1973

ATELIERS DE LA MOTOBECANE, Pantin, France

¹¹ Fuel injection pumps for internal combustion engines "·

In its French patent specification no. 72 27782, the applicant wrote a device for the electromagnetic control of fuel injection pumps for two-stroke engines, which works with pulses with a controlled return stroke. In this regard, the signal acting on the coil of the 'injection pump' has two phases:

1.) a primary shock-like impulse phase, the energy of which compresses the return spring. Also leads the needle makes a stroke which is proportional to the • energy of this jerky impulse.

This energy essentially influences the stroke and varies according to the design of the injection pump the passage cross-section and, accordingly, the current delivery volume or, in other words, the amount of fuel injected per unit of time.

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2.) a corrective secondary impulse phase, the energy of which is deducted from the work of the return spring and which influences the return stroke of the needle.

This secondary pulse energy extends the duration of the return stroke of the needle and, accordingly, the duration of the injection pump.

In such a device, in which the freedom of the needle-spring system is given immediately when the needle has left its seat, the presence of a stop for the purpose of stroke limitation is completely excluded, because this stop would limit the stroke that one would rather have free, and would also have been Cutback phenomena occur disturbing.

Such a device no longer has any limitation for the advance of the needle, which has the particular advantage that the control requires less energy, since the needle does not have to be held against the force of a spring against the force of a spring for a certain period of time. In addition, precise machining is superfluous, in particular the ground stop surface of the needle and the stop itself.

In addition, the elimination of this needle stop facilitates the disposal of the fuel, which is more direct Railway stops. .

Finally, the non-stop needle can be obtained by piercing from a rod with a smaller diameter . The material of this needle is an expensive alloy steel.

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" ³ " 23A3243

However, the lack of this stop requires a precise starting stroke, otherwise the path of the needles i.e. their position in the time function is not guaranteed and, accordingly, the fuel delivery is not correct. In order to be able to control the pump comfortably and precisely, an element is necessary that influences the starting energy.

This regulation option has the advantage that an otherwise necessarily very precise initial pulse control can be eliminated and you can also have less strict machining tolerances of the Accept the needle on its spigot part, as well as on the end of the nozzle that this spigot cooperates with, continue the part of the needle, which is the rotating surface and is intended to be on the conical Seat to come to rest, as well as the conical seat itself, which is in the body of the injection pump is housed and forms the rest position stop of the needle.

Understandably, if the machining is less precise, the relationship between the passage area is for the fuel and the needle position not the same from one injection pump to another. It is rather, after the amount of fuel to be injected with each stroke, on the one hand, from the passage quersc ' suffered for the fuel and, on the other hand, depends on the stroke of the needle, you can just change it by comfortable Ver of the stroke of the needle by the means according to the invention compensate for the inequalities in the passage cross-section can.

According to the invention manual means are provided to progressively the distance between the coil and the

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To be able to change the core with which the needle is firmly connected is to arbitrarily change the energy that causes the needle to rise.

Such a solution brings an obvious step forward over the use of spacers or the approximation of masses in a known manner and with changing the distance between the part of the injection pump with the coil and its core on the one hand and the part which the The nozzle and the resting position receptacle for the needle, d. H. change the nose of the injection pump instead of the distance between the core of the bobbin and the core of the needle.

Further features of the invention and the advantages achieved by the same emerge from the following Description in which, with reference to the drawings, exemplary embodiments of the subject matter of the invention are explained. In the drawings show:

1 to 4 schematically four variants in longitudinal section;

FIG. 5 shows an additional view of FIG. 3.

In all of the figures, 1 denotes the body of the injection pump and 2 denotes its nozzle, which the needle 4 receives in the rest position, on which a spring 5 acts. 6 denotes the coil of the control solenoid, its core when the coil is acted upon, it attracts the core 8 to which the needle 4 is connected. The distance between the two Cores is denoted by 9.

When the nozzle 2 is axially displaced, it takes the needle 4 with it, which in the rest position rests against the support 3 and accordingly the distance changes 9.

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The connection contacts of the coil 6 are denoted by 10 and the connection of the pump to the supply lines with Ii for fuel supplied under pressure. This runs through the channels 12, 13, 14, 15, the ring passage 16 and the grooves 17 and arrives at the support 3 of the needle, the pin and then in the area of this support forms the distributor 18 in a manner known per se.

In the first embodiment, which is shown in Fig. 1, the nozzle 2 is seen with an external thread 20 ver and in the front part of the body 1 of the injection purple tape a corresponding internal thread 21 is provided, one Lock nut 22 makes it possible to block the nozzle in the selected setting, which corresponds to the distance 9. The axial displacements of the nozzle take place against the Y / ir effect a spring washer 23.

Fig. 2 shows a variant of this first embodiment. The front part of the body 1 of the injection pump has an external thread 31 onto which a cap 32 is screwed which is connected to a locking ring 33. By acting on the cap 32 against which the nozzle 2 is supported with its shoulder 34, the distance which the nozzle 2 from the body 1 can be varied the injection pump separates and accordingly the stand 9.

In these two variants, the spring ring 23 will see zwi the nozzle 2 and a ring 35, which is intended to close the magnetic flux.

Another solution shown in FIG. 3 consists in acting on the core 7 of the bobbin 6 in order to more or less remove it from the core of the needle 4 in the rest position .

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the
In this case, ⁷ "core 7 andthe connection 11 for the fuel no longer a piece. The core 7 has an external thread 36 which is screwed into an internal thread 37 of the terminal 11" is imagining. The longitudinal displacement of the coil core is made possible by a hexagon socket 38 which is provided at the rear end of the core 7. A locking ring 39 made of nylon secures the blocking of the core in its position is set.

FIG. 5 shows a device which is used for adjusting the movable core 7 in the exemplary embodiment according to Fig. 3 can be used. In a body 42 with a pipe 43 which connects to the fuel line is connected, a rod 44 can be moved axially, which carries an operating button 45 on the outside and the opposite end of an external hexagon 46 corresponding to the internal hexagon 38 of the core forms. The seal is screwed onto an inner lining 48 with a shoulder in the body 42 Cap 47 ensured, this cap pressing the three seals 49.5o, 51 together at the same time. On an extension of the chuck 48 is an elastic, tubular connection in a suitable manner.

piece 52 attached, which are attached to the connection of FIG. 3, for example by means of a clamp can.

The chuck 48 has radial bores 53 and the rod 44 Aveist has a diametrical bore in the form of a channel 54 which is in communication with an axial channel 55 which opens at the end of the chuck and through which the fuel to the injection pump can ge long.

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The device shown in Fig. 5 is intended in the manufacturing plant for the initial setting of the A injection pump to be used. This is followed by dismantling in order to directly connect the supply line for fuel to the connection 11 borrowed, whereupon the movable core 7 is no longer convenient is accessible. This prevents unintentional interference by the user that could aim at the To change the delivery rate of the injection pump, which lead to increased pollution of the atmosphere would.

According to FIG. 4, the core 7 and the connector 11 are for the fuel line made of one piece and this piece has an external thread 40, which is a Displacement of the core through external influence ■ allowed. A clamping lock nut 41 is still seen before.

The construction details of the injection pump were neither described nor shown. She will of course have suitable seals between their elements in relative movement, which have been designated, for example, at 24, 25 and 26 in FIG.

On the other hand, numerous variations can be made to the exemplary embodiments described and illustrated without leaving the scope of the invention.

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Claims (9)

Patent claims: 1.) Fuel injection pump for two-stroke engines with electromagnetic control by a coil and without limit stop for the stroke of the Needle in operation which is held elastically against its seat by a spring, characterized in that that manual means of progressively changing the distance between the coil and the core with which the needle is firmly connected, and thus intended to change the "stroke energy" applied to the needle are. 2.) Injection pump according to claim 1, characterized in that the nozzle in the longitudinal direction with respect to of the fixed core of the coil is adjustable. 3.) Injection pump according to claim 1, characterized in that the core of the coil in the longitudinal direction with respect to the fixed nozzle, which forms the resting position of the needle, is adjustable. 4.) Injection pump according to claim 2, characterized in that the nozzle has an external thread, the one on the internal thread of the injection pump body for axial adjustment of the rest position receptacle the needle is screwed in. 409822/0280 23A3243 5.) Injection pump according to claim 2, characterized in that the nozzle is against an internally threaded cap supported, which is screwed onto an external thread of the injection pump body. (Fig. 2). 6.) Injection pump according to claim 4 to 5, characterized in that an elastic seal is arranged between the nozzle and the injection pump body (Fig. 1 and 2.) 7.) Injection pump according to claim 3, characterized in that the coil core has a rearward one Has part with an external thread with which it is screwed into the connection piece of the fuel line wherein the free end is provided with an engagement for a tool for manual rotation. 8.) Injection pump according to claim 7, characterized in that it has a displacement of the rotating ble and having axially movable core after adjustment of the distance preventing friction elements. 9.) Injection pump according to claim 3, characterized in that the core of the solenoid with the The connecting piece of the fuel line is designed in one piece and the connecting piece has an external thread has, the axial adjustment of the said core (Fig. 4) .gestetzt by rotation. 409822/0280