FR2617238A1 - ADJUSTING DEVICE FOR AN ELEMENT FOR ADJUSTING THE SUPPLIED FUEL QUANTITY OF A FUEL INJECTION PUMP - Google Patents

Abstract

a) Adjustment device for an element for adjusting the quantity of fuel supplied to a fuel injection pump; b) Characterized in that the device for adjusting the quantity supplied at start-up 38 comprises a pivoting adjustment lever stopper 41 movable in the pivoting zone of the adjustment lever 24 and a drive assembly 42 rotating the lever stopper adjustment 41, which rotates the latter when the injection pump is stopped and rotates it again after starting the fuel injection pump; c) The invention relates to an adjusting device for an element for adjusting the quantity of fuel supplied to a fuel injection pump.

Description

ADJUSTING DEVICE FOR AN ADJUSTMENT ELEMENT

  FUEL QUANTITY SUPPLIED FROM INJECTION PUMP

FUEL

  In fuel injection pumps, the fuel quantity adjustment element fed in the form of an axially displaceable annular spool is supported, in a manner known per se, on a pump piston, and controls during the lifting of the pump. pump piston a crimp opening connected to the working chamber of the pump in the pump piston. For each

  position of the adjustment element of the quantity of car-

  In this case, the pump piston leads to a greater or lesser amount of lift, is disengaged before the discharge opening and connects the working chamber of the pump under high pressure with the inner chamber of the pump located below the supply pressure. Thus, the supply of fuel from the working chamber of the pump to the injection nozzle terminates abruptly, so that, for constant pump piston uplift, the position of the control element of the amount of fuel fed relative to the discharge opening determines the amount of fuel to be fed for lifting the pump piston. The adjustment device thus controls the position of the fuel quantity adjustment element fed to the piston of the pump according to the operating parameters of the internal combustion engine, such as the speed of the engine.

  rotation and load. The device for adjusting the quantities

  The start-up integrated in the adjusting device therefore determines the amount of fuel supplied during start-up of the internal combustion engine and from the pump piston by starting.

  of the fuel injection pump.

  On a known adjustment device of this technique (DE-OS 31 47 701), the device for adjusting the quantity of fuel supplied at start-up is formed of a stop disposed at a stationary position on the steerable path of the lever of tension and pressure. a choke spring placed between the positioning lever and the tension lever, which in the starting position of the fuel injection pump in which the tensioning lever is pulled due to the spring tension against the lever stop tension, moves the adjusting lever of the tension lever by the regulating sleeve without action on the injection pump in the idle state and thus moves the adjusting element of the quantity of fuel supplied to the position of the quantity of fuel. start-up. The starting amount supplied in this position of the fuel quantity adjusting member fed from the pump piston is always greater than the amount at full load which is then fed from the pump piston when the adjustment of the amount of fuel fed occupies a position on the pump piston which is determined by the fact that the tension lever abuts the abutment of the tension lever, but that the choke lever from the regulating sleeve is adjacent to the tension lever under the effect

the force of the choke spring.

  On direct injection internal combustion engines, for example diesel engines, on which the fuel is not injected into a prechamber into the cylinder but directly into the combustion chamber, the quantity of fuel required to start the combustion engine is less than that to be injected under full load. The known adjustment device, because of its construction, is therefore suitable for fuel injection pumps

  on direct injection internal combustion engines.

  The adjustment device according to the invention for an element for adjusting the quantity of fuel supplied with the features of claim 1 has, on the other hand, the advantage that, by the device for adjusting the quantity fed at the start, the quantity at startup can be set below the amount at full load. The cessation of the adjustment of the starting quantity then occurs automatically due to the supply pressure being established in the working chamber of the pump with starting of the pump

  fuel injection and that of the fuel pump.

  associated with it. The fine adjustment of the starting quantity can without problem be predetermined by the

  adjustment rod, such adjustment or readjustment

  can be carried out in the service station. The choke spring and the stop of the tension lever can escape the stroke of the tension lever since both functions are provided by the stop that can pivot inwards or outwards of the travel path of the

positioning lever.

  The adjustment device according to the in-

  vention can also be used on injection pumps

  of fuel with a stop of full load

  load pressure (LDA) or atmospheric pressure (ADA). In this case, the full load abutment may be formed by the abutment of the adjustment lever according to the invention which is released after starting its drive and can then be subjected to a setting process for the regulation as a function of the pressure of the load or atmospheric pressure of the quantity at full load through the known control station. Other variants and advantageous improvements of the device according to

  Inentiocn are described in the following of the invention.

  The invention is explained in more detail with the aid of an embodiment shown

  by the figure and the following description. For this purpose,

  Fig. shows an adjusting device for an element for adjusting the amount of fuel supplied from a fuel injection pump with other components of this

  last used for understanding.

  The adjustment device shown

  in the figure for an adjustment element of the quantity

  fuel tank fueled by a fuel injection pump

  In the interior of the pump designated by the reference, it is placed in the interior chamber of the pump which is surrounded by a pump housing, not shown, which is closed by a pump cover 11 in section. In the casing of the fuel injection pump is introduced a distributor cylinder 12 in the bore of which a pump piston 13 moves in a reciprocating movement and simultaneously rotated by means not shown in more detail, delimiting a working chamber of the pump 14. This

  fuel is fed by longitudinal gorges.

  dinales 15 placed on the surface of the casing of the pump piston 13 and a channel 16 extending in the distributor cylinder 12, during the suction stroke of the pump piston -13 from the inner chamber of the pump In a manner known per se, the inner pump chamber 10 is, in a manner known per se, filled with fuel which is synchronously driven by the pump piston 13 fed by a fuel supply pump from a pump. Fuel tank. During the compression and supply movement of the pump piston 13, the fuel is conducted from the working chamber of the pump 14 into a longitudinal channel 17 extending into the pump piston 13, from which the fuel is introduced. by a longitudinal groove of the distributor 18 corresponding to the rotational position of the pump piston 13 in one of the injection lines 19 leading to the injection nozzles which are distributed in a number corresponding to the number

  injection nozzles to be fed to the periphery of the

  wise of the dispatcher cylinder 12.

  On the pump piston 13 releasably supports the quantity control element

  powered fuel formed of an annular spool 20.

  The latter controls a radial bore 21 in communication with the longitudinal channel 17 on the path of the supply path of the pump piston 13 and thus provides a direct connection between the working chamber of the pump 14 and the inner chamber of the pump. 10, so that from this point of distribution of the working chamber of the pump 14, it empties suddenly and the remaining fuel fed from the piston of the pump 13 is no longer driven to the injection pipe 19,

  but flows from the inner chamber of the pump 10.

  after each installation of the annular spool 20, the communication of the working chamber of the pump 14 to the inner chamber of the pump 10 thus opens later or later and, in this way, the feeding

  fuel is interrupted. In addition, the drawer

  20 is moved towards the top dead center of the pump piston 13 in a manner that increases the amount of fuel supplied from the pump piston 13 in each of the injection lines 19 is high. The spool 20 is moved from an adjusting device 22 with respect to the pump piston 13. The adjusting device 22 comprises a two-armed adjustment lever 24 pivotable about a stationary axle 23 and a lever With the lever arm facing the annular spool 20, the adjusting lever 24 carries a head 26 which, for the axial displacement of the annular spool 20, engages with a lever 25 which can pivot about the same axis. cavity 27 of the latter. On the tensioning lever 25 engages an adjusting spring system 28. This device consists of a main adjusting spring 29, one end of which is fixed to an eccentric 30 which can be adjusted at will and whose other end is engages on a spring cup 31 with a guide bolt introduced through a bore 32 into the tensioning lever 25, bolt on which is placed an adjusting spring of the idling step 33 resting on the tensioning lever 25. The tensioning lever 25 carries, in addition, a protrusion 34 on which the adjustment lever 24 can be placed to cooperate with the tension lever 25. Between these two levers, it is possible to place a leaf spring 35 which serves for positioning by pressing the adjusting lever 24 on a control sleeve 36 of a rotational force regulator of the centrifugal force designated by the reference 37. The latter is in itself cannully driven by a device ent rIement, not shown here, corresponding to the speed of rotation of the pump piston

  13, the control sleeve 36 whose rotation speed

  increase is being displaced by the action of the mass

  centrifuge to the right of the figure.

  The adjusting device furthermore comprises a starting quantity adjusting device 38 which, by means of the adjusting lever 24, causes the annular spool 20 to move to a relative position on the pump piston 13, in which during the movement of the pump supply of the pump piston 13 is supplied with a fuel injection quantity necessary-when starting, the radial bore 21 leaves the annular spool 20. The starting quantity adjusting device 38 comprises a stopping lever to two arms pivotable about a fixed axis 39 which carries, at the end of one of its lever arms, a stop 41 for the adjusting lever 24 and on its other lever arm engages a set 42 for the pivoting of the stop lever 40. This is arranged so that the stop 41 can pivot in one direction and in the other in the pivoting path of the adjusting lever 24. For this purpose , the stop lever 40 is char by a spring in the direction of pivoting, in the exemplary embodiment by means of a branch spring 44 resting on one side on the stop lever and the other on a fixed pin 43 and is applied

  in the direction of the pivotal recall by the set of

TREATMENT 42.

  The drive assembly 42 includes a displacement piston 45 which is guided axially movably in a bushing 46. Both the displacement piston 45 and the bushing 46 are in the form of steps, where the transition shoulder 47 between the two bushing sections form a stop for limiting the stroke of the displacement piston 45. At its rear end, the displacement piston 45 comprises an open cavity 48 of the frontal side into which a driving spring 49 formed of a coil spring. This drive spring 49 is supported, on one side, on the displacement piston 45 and, on the other, on a cover 50 which closes the rear end of the bushing 46 and is fixed on the edge of the socket by folding. The drive spring 49 places the displacement piston 45 in

  its immutable base position with its shoulder of

  51 between the two piston sections on the

  Transition 47 in bushing 46.

  On the displacement piston 45 is provided a stepped bore, passing right through the center, whose largest diameter section opens into the cavity 48 on the displacement piston and whose smallest section diameter reaches the the front side of the displacement piston 45 turned towards the cylinder 48 and behind it, the piston 45 forming a face of the piston 53 to receive the pressure of the displacement piston 45. The smaller bore diameter diameter section an internal thread 54 in which an adjustment pin 55 is screwed by means of a corresponding external thread 56. The adjusting spindle 55 projects substantially over the face 53 of the displacement piston and penetrates the other side into the cavity 48 on the displacement piston 45. In the region of the stepped bore section 52 the strongest in diameter, the adjusting pin 55 is held by an O-ring 57 which is sealingly on the inner wall of the bore section of the smaller diameter bore 52. At its end in the cavity 48, the adjustment pin 55 carries a housing 58 for the insertion of a rotation tool 59, for example a key awl. Coaxially with this housing 58, the lid carries a threaded connection 60 for connection to a fuel return line which includes an opening

  61 penetrating up inside the socket for the eva-

  The opening 61 is furthermore formed in such a way that the rotating tool 59 penetrates and can be plugged into the housing 58.

in the adjustment spindle 55.

  The bushing 46 is screwed with its section having the smallest diameter in the threaded bore 62 passing right through the pump cover 11 where the adjusting pin 55 penetrates back to one of the lever of the stop lever 40, which is in the starting position of the adjusting device shown in the figure under the effect of the force of the spring branch 44 on the adjusting pin 55. The force of the spring to branch 44 is chosen smaller than that of the drive spring 49 so that the stop-adjusting lever 41 of the stop lever 40 is swung over the path of the adjusting lever 24. By turning the adjusting pin 55 to means of the rotation tool introduced through the opening 61 in the

  threaded connection 60, the desired position of the Zute-

  adjusting lever 41 can be adjusted very precisely.

  The face of the piston 53 of the displacement piston 45 then releasing at the rear for the inner chamber of the pump 10 is applied by the supply pressure prevailing in the inner chamber. The force of the drive spring 49, the spring force 44 and the dimensions of the piston face 53 are determined relative to one another so that

  the start of operation of the fuel injection pump

  burant thanks to the feed pump so driven

  synchronous, the supply pressure being established at the in-

  inside the pump chamber 10 by the return force

  the brake spring 44 causes the piston of movement

  45 against the action of the drive spring 49 and pushes up to the adjusting pin 55 on the cover 50. By withdrawal of the displacement piston 45, the stop lever 40 follows under the effect of the branch spring 44 of this displacement and the stop 41 is tilted out of the path of the adjustment lever 24. By the corresponding configuration of the stop lever 40, it forms, in its rotated state, a stop for the tension lever 25 on which it relies upon full charge and then sets the necessary amount that is fed to

  full load by the pump piston 13.

  By rotating the adjusting pin 55, the stop lever can in its conversion position shown in the figure be more or less tilted, the stop 41 moving in the figure is more to the right, or more to the left. It is thus possible to adjust

  the amount of pre-seeded startup. On injection pumps

  In the case of fuel injection on direct injection internal combustion engines, the stop 41 is furthermore placed so that the starting quantity is less than the amount at full load. With the starting quantity setting device 38, it is also possible for other use cases to set the starting amount higher than that at full load; in this case, the stop 41 is moved more widely to the left in the figure by rotating the adjusting pin in the opposite direction. Thus, the adjustment device can be used universally for all types of fuel injection pump independently of its

specific use.

  The control device described here operates as follows: When starting the internal combustion engine, the supply pressure in the inner chamber of the pump 10 is zero due to the fact that the supply pump is not depressed with the fuel injection pump. The displacement piston 45 of

  the drive assembly 42 is, thanks to the spring of

  Trace 49, plated on the transition shoulder 47 and takes the position shown in FIG. The stop lever 40 is tilted by the adjusting pin 55 to the extent that the stop 41 is on the travel path of the adjusting lever 24. The tension lever 1i1 is located by the pre-tension of the spring device adjustment device 28 by its protrusion 34 on the adjustment lever 24 and is fixed in the same way further by the stop 41. The annular spool 20 takes on the pump piston 13 a position through which the amount of fuel fed at startup is determined by the

  next feeding stroke of the pump piston 13.

  After start-up, the feed pressure

  tation increases in the feed chamber, the feed pump being in operation and causes the displacement piston 45 to move against the direction of action of the drive spring 49 until it strikes the end. of the adjusting spindle 55 located in the cavity 48 of the displacement piston 45 on the cover 50 closing the sleeve 46. Under the effect of the branch spring 44, the stop lever 40 of the displacement back of the spindle of setting 55 follows and the stop 41 is flipped

  out of the travel path of the adjustment lever 24.

  With the start of the internal combustion engine, the control sleeve 36 is tilted with increasing speed of rotation and is moved to the right of the figure to the stop on the adjustment lever 24. By a subsequent increase of With the speed of rotation, the regulating sleeve 36 moves the adjustment and tensioning levers 24, 45 adjacent to one another. Against the pretensioning force of the spring-loaded adjusting device 28 by which the annular spool 20 is moved to the left of the figure in the direction of the

  lower fuel injection amount. In the event

  keeping the rotational speed steady the drawer

  ring 20 has reached the position for a quantity of

  lowest fuel consumption. Correspondingly to the load or pre-tension of the adjusting device to

  28, the amount of fuel injection is

  variable at each speed of rotation. The highest injection quantity occurs at full load and is limited by the stop formed from the stop lever 40 for the tension lever 25, the latter being to the left of its starting position represented by the Fig.

Claims (1)

  5. An adjusting device for an element for adjusting the quantity of fuel supplied from a fuel injection pump, comprising a two-arm adjustment lever pivotable about a fixed axis which is coupled to the element of the quantity supplied, a tension lever pivotable about the same axis, which is applied by the force of a spring adjustment system whose voltage can vary at will depending on the desired load or the speed rotation, a rotationally displaceable control sleeve that can be applied by gravity to the adjusting lever, and a starting quantity adjusting device which causes the adjusting lever to move the quantity control element supplied to a displacement position determining a fuel injection quantity fed during the start of the fuel injection pump, characterized in that the device for adjusting the amount fed to the start 38 comprises a pivotable adjusting lever stop 41 pivoting in the pivoting zone of the adjusting lever 24 and a driving assembly 42 rotating the thrust lever 41, which pivots when the injection pump is stopped and rotates again after the pump is started. fuel injection. 2- Adjustment device according to   claim 1, characterized in that the training set   42 is controlled by the feed pressure of a feed pump commonly driven by the fuel injection pump which, after starting the latter,   takes a value greater than zero. 3- Adjustment device according to   claim 2, characterized in that the training   42 comprises a return spring 44 actuating the adjusting lever stop 41 in the direction of external pivoting and a displacement piston 45 acting on the adjusting lever stop 41 under the effect of a drive spring 49 in the direction of reverse pivoting, the displacement piston comprising a piston face 53 applicable by the supply pressure against the direction of action of the driving spring 49; and in that the return spring 44 and the biasing spring 49 are formed such that the force of the drive spring 49, on one side, is greater than that of the return spring 44 and on the other hand, is lower than that of the return spring 44 and after starting of the fuel injection pump by the supply pressure the resultant of the force   displacement is exerted on the displacement piston 45.   4- adjusting device according to claim 3, characterized in that the thrust-adjusting lever 41 is disposed on an arm of a two-arm stop lever pivotable about an axis of rotation 39 which, with its other arm, is adheringly supported by the return spring 44 on the piston of   moving 45 of the training assembly 42.   - Adjustment device according to one   Claims 3 or 4, characterized in that the piston   45 is guided axially in a sleeve 46 and is placed under the action of a drive spring 49   advantageously constituted by a helical pressure spring   coidal on a stop shoulder 47 limiting the movement of movement within the sleeve and in that the sleeve 46 is sealingly introduced with the end facing the face of the piston 53 of the displacement piston 45 in an opening 62 of the pump cover 11 which closes an inner chamber 10 of the fuel injection pump under the supply pressure. 6. Adjusting device according to claim 5, characterized in that in the displacement piston 45 is held, so as to be able to move longitudinally, a setting pin 55 through the entire length which projects on the piston face 53 and there is covered by the stopper   40 and has at its other end a housing   troduction 58 for an adjustment tool 59.   7- An adjusting device according to claim 6, characterized in that the displacement piston 45 comprises a central axial stepped bore 52 whose bore section having the smallest diameter carries an internal thread 54 in which is screwed the pin of adjustment 55 by an external thread 56, and in that on this adjusting pin 55 is maintained a sealing ring 57 which bears sealingly on the inner wall of the bore section   of stepped lining 52 having the largest diameter.   8- adjusting device according to claim 7, characterized in that the sleeve 46 on which the end facing the piston face   53 is closed up to a flow opening of the quantity   61 and there is a spring chamber receiving the drive spring 49, and in that the insertion housing 58 is disposed at the end of the spring chamber adjusting pin coaxially with the opening of the spring 61 and is adapted to receive a rotating tool 59 that can pass through the reflux opening 61.