FR2746447A1 - INSTALLATION FOR TRANSFERRING FUEL FROM A TANK TO THE ENGINE OF A MOTOR VEHICLE, BY A GEAR PUMP OR TRANSFER PUMP AND A SEMI-ROTATING CELL PUMP - Google Patents

Abstract

Installation comprising a gear pump (3) in the motor supply line from the tank; this pump has in its body (1) at least one pump chamber (23) with delivery elements driven in rotation transferring fuel from a suction chamber connected to the tank into at least one pressure chamber directly connected to the engine internal combustion. The pump (3) forms an assembly with a rotary cell pump (5), the suction side of which is connected to a brake force amplifier of the vehicle to create a vacuum.

Description

State of the art:

  The invention relates to an installation for transferring

  fuel from a tank to an internal combustion engine

  dull of a motor vehicle, comprising a transfer pump in the supply line of the internal combustion engine from the tank, this pump having in its body at least one pump chamber with elements of

  delivery driven in rotation, in particular a fuel pump

  grenades transferring fuel from a suction chamber

  connected to the reservoir in at least one pressure chamber

  linked directly to the internal combustion engine, the transfer pump forms a construction assembly with a

  semi-rotary air transfer cells, the vacuum side of which

  ration is connected to a brake force amplifier of the vehicle

  automobile vehicle to create a depression.

  Such installations consist in a known manner of a fuel transfer pump preferably driven by the internal combustion engine and which pumps the

  fuel from a tank to transfer it to the

  internal bustion or to a high pressure injection pump of the engine.

  According to document DE 27 09 913 C2, there is known a gear pump intended to transfer fuel from a tank to an internal combustion engine; in his body,

  the pump has a chamber provided with a pair of impellers

  interlocking tees and driven in rotation; these cogwheels

  transfer a liquid (e.g. fuel) from a room

  bre of suction along a transfer channel formed between the front surfaces of the toothed wheels and the wall of the

  O30 pump chamber to a pressure chamber.

  In addition, for internal combustion engines of motor vehicles, it is known to provide thereon

  a vacuum pump to create a vacuum for an am-

  motor vehicle braking force planner.

  This vacuum pump is preferably driven by the internal combustion engine; it is also scheduled on

  this pump or on a high pressure pump.

  Known systems nevertheless have the drawback

  deny being separate sets, thus having an encom-

  significantly considerable and to be of significant manufacturing cost. Advantages of the invention: The present invention relates to an installation of the type defined above, characterized in that the air pump housed in the common body with the transfer pump is a semi-rotary cell pump with a rotor rotating in the

  body, this rotor comprising guide slots for receiving

  see several fins whose outer, axial ends slide in leaktight manner against the wall of a pump chamber eccentric with respect to the axis of rotation of

the semi-rotary cell pump.

  It is particularly advantageous for the pump assembly formed by a gear pump and a semi-rotary cell pump to be arranged axially one

  behind the other; not only does this minimize the

  space but allows for a single drive shaft, common. This drive shaft requires only a connection with the camshaft; this connection is advantageously made using an elastic coupling element in the form of a connection

  with key and groove (key disc, elastic)

  position tolerances between the ends of the ar-

  bres and also allowing a decoupling of vibrations

  between the camshaft of the internal combustion engine and the

  pump drive bre; the gear pump consists of

  kills another hydraulic damping element between the

  semi-rotary cell pump rotor and camshaft.

  In addition, the force bond between the camshaft and

  the drive shaft constitutes a breaking point

  sign which, in the event of a sudden blockage of one of the pumps or

  of the drive shaft prevents mechanical destruction.

  The advantageous mounting of the drive shaft and

  of the rotor of the semi-rotary cell pump on the

  cylindrical height of the pump body allows the drive shaft

  drag only transmit torque to the semi-rotary cell pump, but does not receive transverse forces, so that the drive shaft can be thinner. In addition, the machining of the external surface of the cylindrical spacer of the pump body serving as a sliding bearing for the rotor and the wall of the pump chamber serving as a circulation surface for the fins of the semi-rotary cell pump. is achievable in a single operation, which reduces the manufacturing cost and the resulting bearing tolerances. The rotor of the

  semi-rotary cell pump and the body can be con-

  formed by an aluminum part injected under pressure; this not only offers the advantage of a reduction in weight but also the fact that the two parts have the same coefficient of thermal expansion and that it is possible to mold the grooves and the holes in the pump body. For protection against wear, aluminum parts can

  moreover being with hard electrolytic oxidation. For a long time

  larger effective fin guide, the fins guided in sliding in the slots of the rotor are moreover arranged

  advantageously at an angle to the radial plane of the rotor.

  O20 Another advantage stems from the realization of this

  for fuel and for the lubricating agent in the pump body in the form of grooves and by the closure

  of the pump body and thus of the pump chambers and ca-

  nals by a simple panel forming a sheet metal cover.

  It is particularly advantageous that the installation

  pump can thus be clamped directly against the cylinder head of the internal combustion engine to be supplied, so that the connection holes for the return of fuel from

  of the internal combustion engine and that the power connection

  fuel indication (pressure side) to the internal combustion engine are directly juxtaposed, which

avoids any hose connection.

  Returning fuel from the combustion engine

  internal tion is done by the transfer facility from

of the tank.

  The pressure control of the trans-

  fert is easier to realize thanks to a single valve

  pressure limitation housed in an open connection channel

  edge in the return line between the pressure channel

and the return channel.

  The common supply of lubricating agent for the two pumps is connected by a connection hole in the pump body to the lubrication circuit of the internal combustion engine. This hole for the lubricating agent made at an angle in the body is offset from the hole in the

  flange, to restrict the supply of lubricating agent.

  The lubricant arrives through the grooves in the surfaces

  sliding bearings and / or drilling in the rotor through

  to the semi-rotary cell pump chamber, ex-

  end of the pump body opposite that of the camshaft

  to exit it by drilling and return to the grease circuit

  wise of the internal combustion engine.

  Another advantage lies in the connection by the

  form between the drive shaft and the driven gear

  born of the transfer pump can be realized by a gou-

  pile housed in a hole passing through the drive shaft, a coupling by a form connection on the drive shaft, a tooth connection with the

  shape, involute or countersunk or a key.

  To limit the fuel supply to the transfer pump and thus the maximum volume flow of the

  pump, there is furthermore provided in a variant a choke point

  for example, a narrowing in the suction line

  tion for example in the suction hole.

  It is also advantageous to provide at the axis seals separating the fuel and the lubricating agent, grooves in the drive shaft which are made to create a pressure drop in the direction of the fuel. Therefore, in case of possible leaks at the level

  axle seals, only lubricant may come

  worm in the fuel system, but never fuel can get into the lubricating oil circuit, which

  would then cause a dilution of the lubricant.

  Drawings: An exemplary embodiment of the installation according to the invention for transferring fuel from a tank to a

  internal combustion engine of a motor vehicle is re-

  shown schematically in the drawings and will be described below in more detail. Thus: - Figure 1 is a section of the transfer installation, - Figures 2 and 3 are two side views corresponding to Figure 1, with the hidden layout of the gear pump chamber and channels of fuel, 10 - Figure 4 is a view similar to that of Figure 2 showing the parts constituting the semi-rotary cell pump, - Figure 5 is a detail of Figure 4 showing the pressure limiting valve placed between the channel of

back and the pressure channel.

  Description of the exemplary embodiment:

  The installation for transferring fuel from a tank not shown to an internal combustion engine also not shown fitted to a motor vehicle or its high pressure injection pump, is only shown in

  Figures 1 to 4 only for components that are important for the

  vention. This installation includes a pump body 1

  read in the form of a gear pump 3 constituting the

  fuel transfer pump and a semi-cell pump

  rotary 5, constituting the air pump (hereinafter called

abbreviated vacuum pump).

  The transfer pump can also be of a type

  different from that of a discharge pump like for example-

  ple a roller pump. The pump body 1 has integrated

  O30 laughingly a circular cavity constituting a pump chamber 7, open towards the front face 9 of the pump body 1, for the semi-rotary cell pump 5; this chamber is delimited radially inwards by a

  cylindrical spacer 11. The cylindrical spacer 11 has

  carries an axial passage 13 guiding in rotation a drive shaft

  drag 15 exiting the pump body 1 in the direction opposite to that of the front surface 9. The free end of the drive shaft 15 projecting from the pump body 1

  carries a drive pulley 17, forcibly mounted,

  both grooves for receiving an elastic connecting element

  that in the form of a key 19, the ends of the key 19 protruding from the drive pulley 17 come to take by a connection by the form in corresponding cavities of the camshaft not shown of the internal combustion engine whose end shaft, free is aligned on this drive shaft; the rotational movement of the camshaft is thus transmitted by the elastic coupling element 19

  and the drive pulley 17 to the drive shaft 15.

  The pump body 1 has on its second face

  front 21 facing the drive pulley 17, a ca-

  oval portion forming the chamber 23 of the gear pump 3;

  this room is separated by a bulkhead from the body

  port to pump chamber 7; it is traversed by the drive shaft 15. A first toothed wheel 25 of a pair of toothed wheels meshing by their front face is mounted on the drive shaft 15 inside the

  pump 23 using a spindle 27 pushed into the drive shaft

  drag 15 ensuring a connection by form. The second toothed wheel not shown is offset at an angle relative to the first toothed wheel 25 according to the front view of FIGS. 2 and 3; its axis is also housed in the body 1 of the pump. As a variant, for the bearing of the second toothed wheel,

  one can also provide a body spacer, cylindrical

  than in place of the axis. An upper segment of the room

  pump 23 radially adjacent to the gears at the top

  of the gear of the teeth, thus forms an as-

  piration 29 and a segment of this pump chamber 23, lower, on the other side of the gear of the teeth constitutes a pressure chamber 31 for the gear pump 3. A suction bore 33 opens into the chamber suction 29 in the pump body; this hole is connected to the tank

through a fuel line.

  > The suction hole 33 may also include a narrowing to limit the maximum volume by a

"strangulation of aspiration".

  A pressure channel 35 starts from the pressure chamber.

  sion 31; this channel is formed by a groove in the front face

  plate 21 of the body 1 of the pump and it extends into a spacer 37 of the pump body 1. In parallel with this pressure channel 35, there is also provided a return channel 39 formed by a groove; this channel is connected by a drilling of

  connection 41 to pressure channel 35 and extends from this

  it substantially to the end of the pressure channel

  35. The pump chamber 23, the pressure channel 35 and the case

  return nal 39 are closed on the opposite side by a first body panel 43 tightly screwed against the face

  front 21 of the pump body 1; this panel 43 comprises a pressure bore 45 starting from the pressure channel 35 and a return bore 47 opening into the return channel 39.15 The body panel 43 is itself clamped on the cylinder head of the internal combustion engine thus supplied so that the per -

  pressure hole 45 and return hole 47 open directly into the corresponding fuel channels of the

  cylinder head. 10 To seal the chamber 23 of the gear pump 3 relative to the internal combustion engine

  dull as well as the semi-rotary cell pump 5, in addition to the various seals of the cover panel, there are also two shaft seal rings 49 on the drive shaft 15 closing the pump chamber 23 on

the drive shaft 15.

  The semi-rotary cell pump 5 shown in more detail in Figures 1 and 4, is formed by a cylindrical rotor 51, housed in the pump chamber 7 and 30 having an axial bore; this rotor is guided by its cylindrical inner wall surface 53 in the manner of a sliding bearing on the envelope surface of the cylindrical spacer 11. The rotor 51 is connected to the drive shaft 15 via 'a coupling disc 55 force fitted on the end of the drive shaft 15 opposite the gear pump 3; this disc is also based

  against the second cover panel 56 closing the chamber 7 of the semi-rotary cell pump 5; this cover panel

  ring is tightly screwed against the front face 9

of the pump body 1.

  The surface of the outer wall 57, cylindrical

  of the rotor 51 which delimits radially inside, the cham-

  bre 7 of the pump, preferably has three slots 59 slidingly receiving fins 61; these fins are tilted in the direction of rotation of the rotor 51 relative to its plane

  radial. As the rotor 51 is eccentric relative to the cham-

  bre 7 of the pump to bear by a part of the surface of its outer wall 57 against the wall 63 of the

  pump 7, the slots 59 are made to allow the ai-

  lettes 61 to penetrate completely or to have sufficient guidance during their maximum excursion while forming sealing surfaces for the fins 61; this sealing is necessary so that when the ends of the fins

  in the rotor 51 are pressurized by the lubricating oil

  wise, the fins 61 are forced radially towards

  outside during the suction phase; thus, the pres-

  and the sealing effect exerted by the fins 61

  the body 1 are especially improved at the speeds of

low rotation.

  When the rotor 51 rotates anti-clockwise (FIG. 4), an upper zone of the chamber 7 of the pump forms a suction zone 65 for the semi-rotary cell pump 5; suction drilling

  67 opens into this suction zone; the drilling is mu-

  nor a suction nozzle 69 receiving a hose from an amplifier

  brake force of the motor vehicle. In order to be able to establish as efficiently as possible a

  3o vacuum in the brake force amplifier, the adju-

  stage 69 is further preceded by a non-return valve 71 provided in the bore 67 and which opens in the direction of the

chamber 7 of the pump.

  The pressure output of the semi-cell pump

  rotary 5 is provided by an outlet bore 73 connected at the level of the smallest section of the pump chamber 7 of the semi-rotary cell pump 5 and at the outlet, by a flange connected to the cylinder head of the engine, ensuring connection to the lubricating oil circuit of the internal combustion engine. The lubrication of the semi-rotary cell pump 5 is done by a drilling of lubricating oil 75 arranged at an angle, appearing in more detail in FIG. 1.

  This hole is connected by a corresponding hole 77 of the first

  mier cover panel 43 to the lubricating oil circuit of the internal combustion engine and opens at the level of the front surface of the rotor 51 in the pump chamber 7. The

  rotor 51 has in its front surface an annular groove

  area 79 to transfer the lubricating agent (oil) as well as

  grooves in the surface of the inner wall 53 and going

  laughing a through hole 81, coaxial; the fertilizer agent

  sage arrives in pump chamber 7 through this hole

  and from this chamber the lubricating agent returns through the

  outlet outlet 73 in the lubricating agent circuit of the engine

  internal combustion engine. This through hole 81 of the exemplary embodiment is formed by the guide slots 59 receiving the fins 61 passing through the rotor 51 in the axial direction. To grease the drive shaft 15, there are also ribs in the wall of the through bore 13. To limit the pressure of the fuel supplied by the gear pump 3, the connecting bore 41 between the pressure channel 35 and the return channel 39 has a valve

pressure limiting 83.

  This pressure limiting valve 83, shown

  felt in more detail in Figure 5, is related to

  return line 85 to the fuel tank of the

  internal bustion; it comprises between the mouth of the pressure channel 35 and that of the return channel 39, a valve 87 held by a valve spring 89 in abutment against a seat 91 formed by a shoulder of the bore. The valve spring 89 bears at its other end against a clamping sleeve 93, the position of which in the connecting bore 41 makes it possible to adjust the preload of the valve spring 89 and thus the opening pressure of the limiting valve. pressure 83. This limit valve

  pressure 83 is used as a pressure control valve

  to continuously limit the maximum volume flow by

  the proportional back pressure which is established.

  The transfer installation according to the invention works

  operates as follows. During the operation of the combustion engine

  internal, the motor camshaft rotates the rear

  drive bre 15 of the transfer installation by

  the elastic coupling at the drive pulley

  ment 17. This rotational movement of the drive shaft is transferred to the first gear 25 of the gear pump 3 which in turn drives the second gear

  meshing with the first. Thus in a known manner, of the car-

  burant is sucked in by the suction hole 33 in the

  serve towards the suction chamber 29 of the gear pump 3. The gear pump 3 is also able to draw in air and supply it so that the emptied fuel lines can ventilate automatically. This fuel is then transferred between the meshed front surfaces of the gears in the pressure chamber 31; from there the fuel is transferred through the pressure channel 35

  to pressure hole 45, then to the combustion engine

  internal or a high pressure injection pump equi-

pant the engine.

  The pressure limitation of the transferred fuel is done using the pressure limiting valve.

  83 equipping the connecting bore 41; from a certain

  pressure, this valve opens in the pressure channel

  sion 35 so that the fuel can escape into the

  return line 85. This return line 85 also serves

  to return fuel not used by the engine to

  internal combustion; for this, the return of the combustion engine

  internal tion opens into the return channel 39 of the installation

  transfer lation; this channel communicates permanently through the connection bore 41 and the return pipe 85 with the reservoir. The rotor 51 of the semi-rotary cell pump 5 rotated by the coupling pulley 55, sucks II during its rotation, air from the braking force amplifier in the chamber 7 of the pump through the nozzle

  suction 69; for this the volume of the different rooms

  bres, delimited by the fins 61 during the rotational movement of the rotor increases between the mouth of the bore of

  branch 67 thus creating a known depression.

  During the rest of the rotational movement, after exchange

  of the respective chamber straddling the connection hole

  67, its volume decreases, so that the volume of air em-

  trapped with the lubricant passing through chamber 7 of

  the pump is transferred under pressure into the outlet hole

  tie 73; from there, this mixture is again supplied to the circuit

  lubricant for the internal combustion engine.

  The non-return valve 71 prohibits the return of

  air to the brake force booster in particular

  bind when the internal combustion engine is switched off.

  The transfer installation according to the invention allows

  thus puts to house separate sets hitherto serving

  to transfer the fuel and create a vacuum,

  simple constructive way, by housing them in a common housing and driving the two assemblies with the same drive shaft, which considerably reduces the cost of

  manufacturing and space requirements.

Claims (13)

R E V E N D I C A T IONS   1) Installation for transferring fuel from a tank to an internal combustion engine of a motor vehicle,   comprising a transfer pump (3) in the supply line   ment of the internal combustion engine from the tank,   - This pump (3) having in its body (1) at least one cham-   pump bre (23) with driven discharge elements   born in rotation in particular a gear pump transferring fuel from a suction chamber (29) connected to the tank in at least one pressure chamber (31) directly connected to the internal combustion engine, -the transfer pump (3) forms a building assembly with a semi-rotary cell pump (5) for transfer   air, the suction side (65) of which is connected to an amplifier   brake force generator of the motor vehicle to create a vacuum, characterized in that the air pump housed in the common body (1) with the transfer pump (3) is a semi-rotary cell pump (5)   with a rotor (51) rotating in the body (1), this rotor   bearing guide slots (59) for receiving several   fins (61) whose outer ends, axial sliding   feels tightly against the wall of a pump chamber (7) eccentric with respect to the axis of rotation of the   semi-rotary cell pump (5).   2) Installation according to claim 1, characterized in that Su the transfer pump constituted by a gear pump (3) and the semi-rotary cell pump (5) are mounted   axially one behind the other and the toothed wheel (25) in   drag of the transfer or gear pump (3) and the   rotor (51) of the semi-rotary cell pump (5) are   dragged in rotation by the same drive shaft (15). 3) Installation according to claim 2, characterized in that the common drive shaft (15) is connected by an elastic coupling element to an axial end of a shaft with   internal combustion engine cam.   40) Installation according to claim 3, characterized in that the elastic coupling element is formed by at least one key (19) of elastic material penetrating each time in a groove provided in the front face of the camshaft and the front face of a drive pulley (17) mounted   force on the drive shaft (15).    ) Installation according to claim 4, characterized in that the end of the drive shaft (15) opposite the member   coupling (17, 19) with the camshaft comprises a device   that forcibly mounted coupling (55), connected by a link   by the shape with the rotor (51) of the semi-cell pump rotary (5).   O6) Installation according to claim 2, characterized by a cylindrical spacer (11) in the pump body (1) whose sliding envelope surface guides the rotor (51) of the semi-rotating cell pump (5) and which has a through hole (13) coaxial with the rotor (51), guiding in   sliding the drive shaft (15).   7) Installation according to claim 1, characterized in that the radially movable fins (61) of the semi-rotary cell pump (5) are disposed tilted in the direction of   rotation of the rotor (51) relative to its radial plane.   8) Installation according to claim 1, characterized in that a connection bore (67) receiving a nozzle (69) for a connecting pipe with the braking force amplifier   opens into the chamber (7) of the semi-cell pump   rotary (5) and the nozzle (69) is preceded by a non-return valve   ti-return (71) opening towards the pump chamber (7).   9) Installation according to claim 1, characterized by a lubrication bore (75) made obliquely in the body   pump (1), connected to the lubrication circuit of the   internal bustion, lubrication hole at which level   che the front surface of the rotor (51) facing the shaft to   cam, and at this mouth, a rai-   ring shape (79) in the front surface of the rotor (51),   from which grooves emerge in the surface of the interior wall   radial (53) and / or a coaxial through bore (81), in the rotor (51), extending towards the front surface (9) of the   pump body (1) opposite the camshaft, as well as a   lubrication of lubricant outlet (73) starting from this over-   front face, and which is connected to the lubrication circuit of the internal combustion engine.    ) Installation according to claim 2, characterized in that the toothed wheel (25) driven by the gear pump (3) or transfer is connected to the drive shaft (15) by a bond by form.   11) Installation according to claim 2, characterized in that   a return channel (39) connected to the return of the combustion engine   internal tion and a pressure channel (35) starting from the cham-   pressure bre (31) of the chamber (23) of the gear pump (3) or transfer pump are produced as grooves in   a front surface (21) of the pump body.   12) Installation according to claims 5 and 11,   characterized in that the pump body (1) is closed at its surfaces   fronts (21, 9) perpendicular to the axis of the drive shaft   dragging (15) each time by a cover panel, a first panel (43) closing the side of the pump body (1) facing the camshaft also closing the chamber (23) of the gear pump (3) as well as the return channel and the pressure channel (39, 35) and a second panel (56) closing the face of the pump body (1) opposite the camshaft,   also closes the chamber (7) of the semi-cell pump rotary (5).   13) Installation according to claims 5 and 12,   characterized in that the coupling disc (55) presses against the second cover panel (56).   14) Installation according to claims 11 and 12,   characterized in that in the first cover panel (43) there is a hole   return (47) opening into the return channel (39) through   both of the internal combustion engine and a pressure bore (45) opening into the pressure channel (35), and against the   front face of the pump body (1), opposite the first panel   neau (43) tightly apply the respective connection holes of the cylinder head of the internal combustion engine. ) Installation according to claim 14, characterized in that a connection channel (41) connecting a return line (85) to the reservoir is provided between the return channel (39) and the pressure channel (35) in the body. pump (1), and in this, the connection between the pressure channel (35) and the return channel (39) permanently connected to the return line (85) comprises a pressure limiting valve (83) ordered at the opening.   16) Installation according to claim 12, characterized in that   the pump chamber (23) of the gear pump (3) is   sealed against the semi-rotary cell pump (5) and the internal combustion engine by two   axle seals (49) mounted on the drive shaft (15).   17) Installation according to claim 2, characterized by a throttling point provided in the fuel supply line (33) opening into the chamber (23) of the pump with gears (3).   18) Installation according to claim 16, characterized in that the shaft seals (49) separating the fuel and the lubricating agent are connected by grooves to the chamber (23) of   the gear pump (3) so as to create a pressure drop in the direction of the pump chamber (23).