Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B43/00—Machines, pumps, or pumping installations having flexible working members
  • F04B43/0009—Special features
  • F04B43/0054—Special features particularities of the flexible members
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B43/00—Machines, pumps, or pumping installations having flexible working members
  • F04B43/02—Machines, pumps, or pumping installations having flexible working members having plate-like flexible members, e.g. diaphragms
  • F04B43/025—Machines, pumps, or pumping installations having flexible working members having plate-like flexible members, e.g. diaphragms two or more plate-like pumping members in parallel
  • F04B43/026—Machines, pumps, or pumping installations having flexible working members having plate-like flexible members, e.g. diaphragms two or more plate-like pumping members in parallel each plate-like pumping flexible member working in its own pumping chamber

Definitions

• the invention relates to a device for transmitting a volume of pressurized fluid, in particular intended for a fuel pump for a direct injection engine. It also relates to a deformable membrane for such a transmission device and to a pump equipped with such a device.
• a device for transmitting a volume of pressurized fluid for example intended for a fuel pump, conventionally comprises an enclosure and a deformable membrane fixed in said enclosure to define two fluid chambers.
• a mechanism such as a piston pump makes a reciprocating movement of a piston which moves in the first chamber, containing for example oil.
• This movement causes a constant volume displacement of the oil contained in the first chamber.
• This displacement causes that of the membrane itself in the second chamber, the latter containing for example gasoline.
• the movement of the diaphragm has the effect of driving the gasoline »in particular towards a collector.
• a fuel supply system for the second chamber is provided to refill this chamber.
• This membrane therefore has both the function of ensuring the seal between the liquids contained in each of the chambers and allow the displacement of the second liquid under the effect of the displacement of the first liquid.
• the membrane of such a device is substantially planar and it is fixed in the enclosure by means of its peripheral edge.
• such a membrane can deform on either side of its rest position.
• the object of the invention is to overcome these drawbacks by proposing a membrane, in particular for a device for transmitting a volume of fluid under pressure, which is not liable to deteriorate under the effect of the stresses to which it is subjected during 'use, and this thanks to a geometry and special characteristics allowing the membrane to work optimally.
• the invention relates to a deformable membrane, in particular for a device for transmitting a volume of fluid under pressure, having a generally rounded shape, characterized in that the membrane comprises, between a central part and a peripheral part, a part intermediate whose cross-section in a transverse plane has a substantially U-shape.
• transverse plane will be understood to mean a plane perpendicular to that in which extends the membrane itself and passing through an axis of symmetry of the membrane.
• the membrane has a generally circular shape, its intermediate part being annular and having a U-shaped section in a diametral plane.
• the peripheral part of the membrane advantageously includes a seal 1 .
• the invention also relates to a device for transmitting a volume of pressurized fluid comprising at least one enclosure and a deformable membrane of generally rounded shape, this membrane comprising a peripheral part by which it is fixed in said enclosure, to define a first and a second fluid chamber, characterized in that the membrane also comprises, between said peripheral part and its central part, an intermediate part whose section in a transverse plane has a shape substantially in a U, so that said intermediate part is able to wind and / or unwind freely during movement of the membrane, during operation of the device, without the bottom of the U-shaped intermediate part coming into contact with said device.
• the membrane is mounted in the device so that at mid-stroke, it has its shape in the free state.
• connection parts of the branches of the U-shaped intermediate part with the central part and the peripheral part of the membrane rest on parts of the device whose shape they follow.
• connection parts can rest freely on said parts or be adhered to them, for example by overmolding.
• the thickness of the intermediate part of the membrane is less than that of the central part and of the peripheral part of the membrane.
• the device comprises a pusher resiliently mounted in the second fluid chamber and which is fixed to the central part of the membrane.
• this pusher comprises a part for guiding the movement of the membrane.
• the membrane has means to prevent its deterioration against sharp edges of said enclosure, consisting in particular, in its central part, in a hollow form or in a rigid valve fixed to the membrane.
• the device comprises means for evacuating the fluid from the first chamber, capable of being trapped between said enclosure and the intermediate U-shaped part of the membrane, these means being in particular constituted by evacuation channels produced in the device itself or in said valve.
• the peripheral part of the membrane advantageously comprises a seal.
• the device for transmitting a volume of pressurized fluid according to the invention comprises several membranes which are formed in one piece.
• the invention also relates to a pump, such as a fuel pump for a direct injection engine, equipped with a device for transmitting a volume of pressurized fluid according to the invention.
• Figure 1 is a schematic and partial cross-sectional view of a device for transmitting a volume of pressurized fluid according to the invention, with a membrane in the high position.
• Figure 2 is a view similar to Figure 1, in which the membrane is in the down position.
• Figure 3 is a view similar to Figure 1, illustrating an alternative embodiment of the membrane according to the invention.
• Figure 4 is a general perspective view of a block of three membranes according to the invention.
• the device for transmitting a volume of pressurized fluid forms an enclosure in which a membrane 1 is fixed.
• This membrane thus makes it possible to define a first fluid chamber 2, located here above the membrane 1 and a second fluid chamber 3, located here under the membrane 1.
• In the first chamber 2 can move a piston 4.
• the piston 4 is in the high position.
• a constant volume of fluid which can in particular be oil.
• a pusher 5 which is resiliently mounted so as to push the membrane 1 against the spacer 6.
• the chamber 3 is filled with a fluid, in particular petrol.
• This elastic mounting is achieved by means of a spring 7 which is mounted between the wall of the chamber 3 and the bottom 50 of the pusher.
• the pusher 5 is extended by a cylindrical guide part 51 which is designed to slide in a corresponding bore 3a of the chamber 3.
• the membrane 1 has a generally circular shape. This also appears in FIG. 4 which shows three membranes 41, 42, 43 similar to membrane 1, formed in a single block.
• the membrane 1 could have another generally rounded shape, for example an oval shape. However, it is a circular shape which seems the most advantageous.
• Figure 1 shows the membrane 1 in section along a diameter.
• the membrane comprises a central part 10, under which the pusher 5 is fixed, a peripheral part 11 by which the membrane is fixed in the device, and an annular intermediate part 12 which has, in diametral section, a shape substantially in U. This U-shaped part is not in contact with any part of the device.
• the peripheral part 11 of the membrane 1 preferably comprises an annular seal 13.
• a function of the membrane 1 being to ensure the seal between the liquid contained in the first chamber 2 and that contained in the second chamber 3, this seal 13 contributes to this function being well ensured by the membrane.
• channels 60, 61 are provided in the spacer 6. These channels have two substantially perpendicular parts, one of which opens into the space 2a between the bottom of the U-shaped part 12 and the spacer 6 and the other, in the orifice 6a of the spacer.
• the orifice 6a of the spacer 6 has a reduced size compared to the upper part 2b of the chamber 2.
• this tightening in bedroom 2 is not compulsory.
• the spacer could be made in one piece with the rest of the device.
• the pusher 5 has lateral orifices 52, 53, the role of which will be explained in the following description.
• the membrane 1 In the position illustrated in FIG. 1, the membrane 1 is in the high position.
• the pusher 5 and the piston 4 are also in their respective high position.
• the piston 4 is pressed into the chamber 2 by suitable means, the liquid, such as oil, contained in the chamber 2 also moves, which causes the membrane 1 to move down.
• the membrane 1 then comes into the low position illustrated in FIG. 2.
• the pusher can guide the movement of the membrane in the chamber 3.
• the liquid contained in the chamber 6, for example petrol is discharged towards the outside of the device.
• the orifices 52, 53 made in the pusher 5 make it possible to evacuate the fluid contained in the space 3b between the bottom of the U and the wall of the chamber 3.
• the means for discharging the liquid contained in the chamber 3 are not illustrated in the figures.
• the chamber 3 When the device according to the invention equips a fuel pump for a direct injection engine, the chamber 3 conventionally opens into a manifold which is itself connected to the engine. Furthermore, at the outlet of chamber 3, a pressure valve can be provided which is not illustrated in the figures.
• the fluid contained in the chamber 3 is evacuated only if it has reached a predetermined pressure.
• the membrane 1 When the pusher passes to the high position illustrated in FIG. 1, the membrane 1 is again pressed against the spacer 6, thanks to the elastic means 7. The membrane 1 is then in the high position illustrated in FIG. from the passage from the low position to the high position, the membrane is still guided in its movement thanks to the guide part 51 of the pusher 5.
• the chamber 3 is again filled with liquid such as petrol, by suitable means which are not illustrated.
• the mounting of the membrane in the enclosure is such that the bottom of the intermediate U-shaped part 12 is not in contact with the walls of the enclosure or with any other part of the device.
• the intermediate part 12 can unroll and wind freely during the movements of the membrane during the operation of the device, without the peripheral part 11 of the membrane being subjected to traction.
• the membrane is preferably mounted in the device so that at mid-stroke, that is to say at an intermediate position between the high position illustrated in Figure 1 and the lower position illustrated in Figure 2, the membrane has its shape in the free state, that is to say without constraints.
• the connecting parts between the constituent parts of the membrane have a particular shape.
• connection part 14 between a branch of the intermediate part 12 and the peripheral part 11 has a suitable shape to match the shape of the wall 30 of the chamber 3.
• connection part 15 between the other branch of the intermediate part 12 and the central part 10 has a suitable shape to match that of the pusher 5.
• connection parts 14 and 15 can either rest freely on the parts of the device of which they take the form, or be adhered to the latter, for example by overmolding.
• the membrane 1 is pushed against the spacer 6 when it is in the high position.
• the opening 6a formed in the spacer 6 has sharp edges which can cause damage to the membrane.
• the central part 10 of the membrane has a hollow shape 10a which makes it possible to avoid contact between the membrane and the edges of the orifice 6a.
• a rigid valve 8 is fixed on the central part 10 of the membrane.
• this valve 8 also makes it possible to avoid direct contact between the membrane 1 and the sharp edges of the spacer 6, when the membrane is in the high position.
• this valve 8 is provided, the evacuation channels between the parts 2a and 2b of the chamber 2 can be produced in the valve 8 itself. These channels consist of grooves, such as those referenced 8a in FIG. 3.
• the thickness of the membrane is advantageously smaller in the U-shaped intermediate part 12 than in the central 10 and peripheral 11 parts.
• the stiffness of the membrane in the intermediate part 12 is thus reduced so that the intermediate part 12 only works in progress. Furthermore, this lower stiffness avoids transmitting the forces undergone by the membrane in this intermediate part, towards the peripheral part fixed in the device.
• the associated membranes can be assembled in a unitary block.
• Figure 4 shows a block of three membranes 41, 42 and 43 which are connected together by planar walls, so as to form a unitary block.
• the device for transmitting a volume of pressurized fluid which has just been described can in particular be used to equip a fuel pump for a direct injection engine.
• the reference signs inserted after the technical characteristics appearing in the claims have the sole purpose of facilitating the understanding of the latter and should not limit their scope.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Reciprocating Pumps (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=9528078

Family Applications (1)

Country Status (4)

Families Citing this family (7)

Family Cites Families (8)

• 1998
  • 1998-06-30 FR FR9808332A patent/FR2780476B1/fr not_active Expired - Fee Related
• 1999
  • 1999-06-28 DE DE69904823T patent/DE69904823D1/de not_active Expired - Lifetime
  • 1999-06-28 WO PCT/FR1999/001548 patent/WO2000000743A1/fr not_active Application Discontinuation
  • 1999-06-28 EP EP99926554A patent/EP1092093B1/de not_active Revoked

Non-Patent Citations (1)

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