EP0157335A2 - Method for damping hydraulic pressure shocks or variations in the supply conduits of a hydraulic pump, and pump adapted thereto - Google Patents

Method for damping hydraulic pressure shocks or variations in the supply conduits of a hydraulic pump, and pump adapted thereto Download PDF

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Publication number
EP0157335A2
EP0157335A2 EP85103536A EP85103536A EP0157335A2 EP 0157335 A2 EP0157335 A2 EP 0157335A2 EP 85103536 A EP85103536 A EP 85103536A EP 85103536 A EP85103536 A EP 85103536A EP 0157335 A2 EP0157335 A2 EP 0157335A2
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EP
European Patent Office
Prior art keywords
hydraulic pump
piston
hydraulic
damping
hole
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP85103536A
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German (de)
French (fr)
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EP0157335A3 (en
Inventor
Alain Devaux
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MAN Energy Solutions France SAS
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Societe dEtudes de Machines Thermiques SEMT SA
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Publication of EP0157335A2 publication Critical patent/EP0157335A2/en
Publication of EP0157335A3 publication Critical patent/EP0157335A3/en
Withdrawn legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
    • F02M55/001—Pumps with means for preventing erosion on fuel discharge
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
    • F02M55/04—Means for damping vibrations or pressure fluctuations in injection pump inlets or outlets
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B3/00—Engines characterised by air compression and subsequent fuel addition
    • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition

Definitions

  • the present invention relates to a method for damping hydraulic pressure waves and for clipping pressure variations in the supply conduits of a hydraulic pump, as well as a hydraulic pump allowing the implementation of this method, which can be, for example, a fuel injection pump or a pump for controlling the positioning of hydraulic cylinders.
  • a method for limiting the pressure waves and for clipping the pressure variations which consists in placing pressure accumulators in the supply conduits or on the body of the pump.
  • pressure accumulators have a capacity commonly reaching 200% of the maximum displacement of the pump.
  • Document GB 468 958 also discloses a device for damping hydraulic pressure waves and for clipping pressure variations, consisting of a movable wall which is resiliently disposed normally in the direction of the fluid jet, but this device is installed on a pump fitted with a feed chamber which does not communicate directly with the device so that the feed hole of the working chamber is separate from the repression.
  • This device then plays the role of a conventional capacity making it possible to absorb most of the quantity of fuel discharged at low loads.
  • the increase in volume is then very significant and, moreover, the movable wall, in the rest position, is very far from the working chamber so that the kinetic energy of the fluid is ineffective.
  • the object of the present invention is to dampen the pressure waves and to limit pressure variations, without having recourse to significant accumulating capacities but by using the kinetic energy of the fluid by direct transfer to the movable wall elastically.
  • the subject of the present invention is a method for damping hydraulic pressure waves and for clipping pressure variations in the supply conduits of a hydraulic pump provided with a supply chamber, consisting in transforming energy potential stored in the excess fluid in the working chamber in kinetic energy, characterized in that this kinetic energy is directly used to temporarily increase the volume of the supply chamber by a value between 10 and 30% of the displacement maximum of the hydraulic pump.
  • the present invention also relates to a hydraulic pump, allowing the implementation of the method according to claim 1, comprising a supply chamber receiving the supply line (s), a piston with rectilinear and constant stroke inside d '' a working chamber, provided with at least one edge regulating in a selectively variable manner the end of the delivery process out of the pump by cooperation with at least one hole putting in communication the working chamber with the feeding chamber , at least one device for damping hydraulic pressure waves and for clipping pressure variations, consisting of an elastically movable wall normally arranged in the direction of the fluid jet, characterized in that the wall is located in the chamber d 'supply, in the axis of a hole and near this hole at a distance not exceeding 1.5 times the smallest diameter of the hole.
  • the movable wall of the device is part of a hermetically sealed and deformable enclosure, mechanically limited in expansion and compression, and containing a gas under pressure possibly accompanied by a liquid and / or possibly a spring, part of the deformable enclosure consisting of a cylindrical tube with corrugated wall , the undulations allowing a deformation along its axis.
  • the movable wall of the device constitutes a piston of low inertia partially closing a housing containing the enclosure, grooves and / or holes provided in the piston or in the wall of the housing putting the housing in communication with the chamber. food.
  • a hydraulic pump according to the invention which is a fuel injection pump.
  • Figure 1 is a schematic view showing the injection pump provided with two damping and clipping devices.
  • Figure 2 is a detailed view of a damping and clipping device.
  • FIG. 1 there is shown a pump body 1, a cylinder 2 fixed in a known manner in the body 1, a cylinder head 3 having a non-return valve 4 closing an orifice 3 ', a piston 10 which delimits between its face upper 15 and the cylinder head 3 a working chamber 5, an annular supply chamber 6, also called collecting chamber 6, placed in communication with the working chamber 5 by means of two holes 7 and finally, two tubular bodies 21 each enclosing a damping and clipping device, these two bodies each opening into the collecting chamber 6, in the axis of a hole 7.
  • the fuel injection pump may have only one hole and an associated device, but generally, an injection pump has two diametrically opposite holes 7 to prevent the piston from being subjected to lateral loads due to hydraulic thrusts. .
  • the piston 10 has a groove 11, a vertical groove 12, another diametrically opposite vertical groove not shown, a recess 13 which delimits an oblique edge 14 and another recess delimiting another oblique edge, not shown.
  • the piston 10 is moved vertically in the cylinder 2, by means of a cam not shown and performs by mounting a compression stroke and descending a suction stroke. Furthermore, a rack, not shown, meshes with a toothing of a part connected to the piston, in order to angularly position the latter and to modify the instant of the end of the injection via the oblique edges.
  • FIG. 2 showing the cylinder 2 provided with a hole 7, there is shown in more detail, a device 20 opening into the collecting chamber 6 opposite a hole 7.
  • This device 20 is installed in a tubular body 21 comprising a bore 36, an external head 22, for example with a hexagon, allowing the tightening of this device, a thread 23 cooperating with a tapping 11 of the pump body 1, and one end 24 provided with a shoulder 25 forming a stop.
  • a seal 40 is interposed between the head 22 and the pump body 1.
  • tubular body 21 is not essential and the bore 36 with the shoulder 25 can be obtained directly by machining the pump body 1.
  • the device 20 comprises a piston 26 freely movable inside the bore 36, a plug 30 stopped in translation by a stop ring 32 and provided with an O-ring 33 ensuring the seal between the plug 30 and the bore 36. Shims 42 in variable number and thickness make it possible to modify the distance at rest between the piston 26 and the plug 30.
  • a cylindrical tube 34 with corrugated wall is tightly connected to the plug 30 and to the piston 26 by through the shoulders 31 and 28.
  • the cylindrical tube 34 as well as the shoulder 28 of the piston 26 and the shoulder 31 of the piston 30 constitute a hermetically sealed and deformable enclosure located in the bore 36 of the tubular body 21.
  • This enclosure is mechanically limited in expansion by the shoulder 25 and the stop ring 32, and mechanically limited in compression because each internal shoulder 28, 31 of the pistons 26 and of the plug 30 has a stop 28 ', 3 T.
  • These two stops also serve as a guide for a spring 35 which is supported on the shoulders 28, 31.
  • the presence of this spring is, of course, not essential because the hermetically sealed and deformable enclosure contains a pressurized gas, possibly accompanied by a liquid to modify the stiffness of the damper constituted solely by the gas or by the gas-spring assembly.
  • the piston 26 has an outer wall or face 27, flat or concave, advantageously made resistant to abrasion by an appropriate surface treatment, such as the deposition of a ceramic material.
  • This face 27 must be at a distance from the hole 7 not exceeding 1.5 times the smallest diameter of this hole.
  • the tubular body 21 has an orifice 37 and the pump body 1 has a groove 38, this orifice 37 and this groove 38 connecting the volume 41 existing between the bore 36, the tube 34, the piston 26 and the plug 30 with the collecting chamber 6.
  • the orifice 37 is produced at a distance 1 from the face 43 of the piston 26 when it is at rest on the shoulder 25. This distance 1 is slightly less than the distance L separating the two at rest stops 28 ′ and 31 ′ and thus, when the piston 26 moves back, closing the hole 37, prior to the mechanical abutment, causes the fuel trapped in the volume 41 to increase in pressure and ensures hydraulic abutment.
  • an orifice 37 ' can be made directly in the piston 26 and, in this case, the groove 38 and the hole 37 are not essential.
  • the variation in volume of the collecting chamber 6 generated by the displacement of the piston is between 10 and 30% of the maximum displacement of the injection pump.
  • the shims 42 make it possible to adjust the preload of the device 20 if necessary.
  • Kinetic energy is available at the outlet of hole 7 in the form of a small mass of fuel driven by a very high speed.
  • the impact that ensues on the face 27 of the piston 26 generates significant erosion.
  • the use of an appropriate treatment intended to increase the abrasion resistance of the face 27 makes it possible to limit the consequences of this phenomenon.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)
  • Reciprocating Pumps (AREA)

Abstract

Procédé d'amortissement des ondes de pression hydrauliques et d'écrêtage des variations de pression dans les conduits d'alimentation d'une pompe hydraulique, et pompe permettant la mise en oeuvre de ce procédé.Method for damping hydraulic pressure waves and clipping pressure variations in the supply conduits of a hydraulic pump, and pump allowing the implementation of this method.

La présente invention concerne un procédé d'amortissement des ondes de pression hydrauliques et d'écrêtage des variations de pression dans les conduits d'alimentation d'une pompe hydraulique, consistant à transformer l'énergie potentielle emmagasinée dans le fluide en excès dans la chambre de travail (5) en énergie cinétique, caractérisé en ce que cette énergie cinétique est directement utilisée pour accroître temporairement le volume de la chambre d'alimentation d'une valeur comprise entre 10 et 30% de la cylindrée maximale de la pompe hydraulique.The present invention relates to a method for damping hydraulic pressure waves and clipping pressure variations in the supply conduits of a hydraulic pump, consisting in transforming the potential energy stored in the excess fluid in the chamber. work (5) in kinetic energy, characterized in that this kinetic energy is directly used to temporarily increase the volume of the supply chamber by a value between 10 and 30% of the maximum displacement of the hydraulic pump.

Elle concerne également une pompe hydraulique permettant la mise en oeuvre de ce procédé.It also relates to a hydraulic pump allowing the implementation of this process.

Application aux pompes d'injection de combustible de moteurs Diesel.

Figure imgaf001
Application to fuel injection pumps of diesel engines.
Figure imgaf001

Description

La présente invention concerne un procédé d'amortissement des ondes de pression hydrauliques et d'écrêtage des variations de pression dans les conduits d'alimentation d'une pompe hydraulique, ainsi qu'une pompe hydraulique permettant la mise en oeuvre de ce procédé, qui peut être, par exemple, une pompe d'injection de combustible ou une pompe de commande de positionnement de vérins hydrauliques.The present invention relates to a method for damping hydraulic pressure waves and for clipping pressure variations in the supply conduits of a hydraulic pump, as well as a hydraulic pump allowing the implementation of this method, which can be, for example, a fuel injection pump or a pump for controlling the positioning of hydraulic cylinders.

Dans une pompe hydraulique à débit variable munie d'un piston à course rectiligne et constante, dans laquelle une arête du piston coopère avec un trou mettant en communication, à la fin du refoulement et d'une manière sélectivement variable, la chambre de travail avec la chambre d'alimentation, la brusque décompression qui accompagne la fin du refoulement génére des ondes de pression qui remontent le ou les conduits d'alimentation de la chambre d'alimentation. Ces ondes de pression sont dommageables pour les composants, filtres et instruments de contrôle par exemple.In a hydraulic pump with variable flow rate provided with a piston with a rectilinear and constant stroke, in which an edge of the piston cooperates with a hole putting in communication, at the end of the delivery and in a selectively variable manner, the working chamber with the supply chamber, the sudden decompression which accompanies the end of the backflow generates pressure waves which flow up the supply duct (s) of the supply chamber. These pressure waves are damaging for components, filters and control instruments for example.

On connait un procédé permettant de limiter les ondes de pression et d'écrêter les variations de pression, qui consiste à placer des accumulateurs de pression dans les conduits d'alimentation ou sur le corps de la pompe. Toutefois, leur inertie ne permet pas un écrêtage satisfaisant et la nature des fluides, éventuellement agressifs ou à température élevée, rend leur durée de vie très aléatoire. Ces accumulateurs ont une capacité atteignant couramment 200% de la cylindrée maximale de la pompe.A method is known for limiting the pressure waves and for clipping the pressure variations, which consists in placing pressure accumulators in the supply conduits or on the body of the pump. However, their inertia does not allow satisfactory clipping and the nature of the fluids, which may be aggressive or at high temperature, makes their lifetime very uncertain. These accumulators have a capacity commonly reaching 200% of the maximum displacement of the pump.

On connait également, par le document GB 468 958, un dispositif d'amortissement des ondes de pression hydrauliques et d'écrêtage des variations de pression, constitué d'une paroi mobile élastiquement disposée normalement à la direction du jet de fluide, mais ce dispositif est installé sur une pompe munie d'une chambre d'alimentation qui ne communique pas directement avec le dispositif de sorte que le trou d'alimentation de la chambre de travail est distinct du trou de refoulement. Ce dispositif joue alors le rôle d'une capacité conventionnelle permettant d'absorber la majeure partie de la quantité de combustible refoulé aux faibles charges. L'accroissement de volume est alors très important et de plus, la paroi mobile, en position de repos, est très éloignée de la chambre de travail de sorte que l'énergie cinétique du fluide est inopérante.Document GB 468 958 also discloses a device for damping hydraulic pressure waves and for clipping pressure variations, consisting of a movable wall which is resiliently disposed normally in the direction of the fluid jet, but this device is installed on a pump fitted with a feed chamber which does not communicate directly with the device so that the feed hole of the working chamber is separate from the repression. This device then plays the role of a conventional capacity making it possible to absorb most of the quantity of fuel discharged at low loads. The increase in volume is then very significant and, moreover, the movable wall, in the rest position, is very far from the working chamber so that the kinetic energy of the fluid is ineffective.

La présente invention a pour but d'amortir les ondes de pression et d'écrêter les variations de pression, sans avoir recours à des capacités accumulatrices importantes mais en utilisant l'énergie cinétique du fluide par transfert direct à la paroi mobile élastiquement.The object of the present invention is to dampen the pressure waves and to limit pressure variations, without having recourse to significant accumulating capacities but by using the kinetic energy of the fluid by direct transfer to the movable wall elastically.

La présente invention a pour objet un procédé d'amortissement des ondes de pression hydrauliques et d'écrêtage des variations de pression dans les conduits d'alimentation d'une pompe hydraulique munie d'une chambre d'alimentation, consistant à transformer l'énergie potentielle emmagasinée dans le fluide en excès dans la chambre de travail en énergie cinétique, caractérisé en ce que cette énergie cinétique est directement utilisée pour accroître temporairement le volume de la chambre d'alimentation d'une valeur comprise entre 10 et 30% de la cylindrée maximale de la pompe hydraulique.The subject of the present invention is a method for damping hydraulic pressure waves and for clipping pressure variations in the supply conduits of a hydraulic pump provided with a supply chamber, consisting in transforming energy potential stored in the excess fluid in the working chamber in kinetic energy, characterized in that this kinetic energy is directly used to temporarily increase the volume of the supply chamber by a value between 10 and 30% of the displacement maximum of the hydraulic pump.

La présente invention a également pour objet une pompe hydraulique, permettant la mise en oeuvre du procédé selon la revendication 1, comportant une chambre d'alimentation recevant le ou les conduits d'alimentation, un piston à course rectiligne et constante à l'intérieur d'une chambre de travail, muni d'au moins une arête réglant d'une manière sélectivement variable la fin du processus de refoulement hors de la pompe par coopération avec au moins un trou mettant en communication la chambre de travail avec la chambre d'alimentation, au moins un dispositif d'amortissement des ondes de pression hydrauliques et d'écrêtage des variations de pression, constitué par une paroi mobile élastiquement disposée normalement à la direction du jet de fluide, caractérisée en ce que la paroi est située dans la chambre d'alimentation, dans l'axe d'un trou et à proximité de ce trou à une distance n'excédant pas 1,5 fois le plus petit diamètre du trou.The present invention also relates to a hydraulic pump, allowing the implementation of the method according to claim 1, comprising a supply chamber receiving the supply line (s), a piston with rectilinear and constant stroke inside d '' a working chamber, provided with at least one edge regulating in a selectively variable manner the end of the delivery process out of the pump by cooperation with at least one hole putting in communication the working chamber with the feeding chamber , at least one device for damping hydraulic pressure waves and for clipping pressure variations, consisting of an elastically movable wall normally arranged in the direction of the fluid jet, characterized in that the wall is located in the chamber d 'supply, in the axis of a hole and near this hole at a distance not exceeding 1.5 times the smallest diameter of the hole.

Avantageusement, la paroi mobile du dispositif fait partie d'une enceinte hermétiquement close et déformable, limitée mécaniquement en expansion et compression, et contenant un gaz sous pression accompagné éventuellement d'un liquide et/ou éventuellement d'un ressort, une partie de l'enceinte déformable étant constituée par un tube cylindrique à paroi ondulée, les ondulations permettant une déformation suivant son axe.Advantageously, the movable wall of the device is part of a hermetically sealed and deformable enclosure, mechanically limited in expansion and compression, and containing a gas under pressure possibly accompanied by a liquid and / or possibly a spring, part of the deformable enclosure consisting of a cylindrical tube with corrugated wall , the undulations allowing a deformation along its axis.

De préférence, la paroi mobile du dispositif constitue un piston de faible inertie obturant partiellement un logement contenant l'enceinte, des rainures et/ou des trous aménagés dans le piston ou dans la paroi du logement mettant en communication le logement avec la chambre d'alimentation.Preferably, the movable wall of the device constitutes a piston of low inertia partially closing a housing containing the enclosure, grooves and / or holes provided in the piston or in the wall of the housing putting the housing in communication with the chamber. food.

Il est décrit ci-après, à titre d'exemple et en référence aux dessins annexés, une pompe hydraulique selon l'invention, qui est une pompe d'injection de combustible.There is described below, by way of example and with reference to the accompanying drawings, a hydraulic pump according to the invention, which is a fuel injection pump.

La figure 1 est une vue schématique montrant la pompe d'injection munie de deux dispositifs d'amortissement et d'écrêtage.Figure 1 is a schematic view showing the injection pump provided with two damping and clipping devices.

La figure 2 est une vue détaillée d'un dispositif d'amortissement et d'écrêtage.Figure 2 is a detailed view of a damping and clipping device.

Dans la figure 1, il est représenté un corps de pompe 1, un cylindre 2 fixé de manière connue dans le corps 1, une culasse 3 comportant un clapet anti-retour 4 obturant un orifice 3', un piston 10 qui délimite entre sa face supérieure 15 et la culasse 3 une chambre de travail 5, une chambre d'alimentation annulaire 6, appelée aussi chambre collectrice 6, mise en communication avec la chambre de travail 5 par l'intermédiaire de deux trous 7 et enfin, deux corps tubulaires 21 enfermant chacun un dispositif d'amortissement et d'écrêtage, ces deux corps débouchant chacun dans la chambre collectrice 6, dans l'axe d'un trou 7.In Figure 1, there is shown a pump body 1, a cylinder 2 fixed in a known manner in the body 1, a cylinder head 3 having a non-return valve 4 closing an orifice 3 ', a piston 10 which delimits between its face upper 15 and the cylinder head 3 a working chamber 5, an annular supply chamber 6, also called collecting chamber 6, placed in communication with the working chamber 5 by means of two holes 7 and finally, two tubular bodies 21 each enclosing a damping and clipping device, these two bodies each opening into the collecting chamber 6, in the axis of a hole 7.

Bien entendu, la pompe d'injection de combustible peut ne comporter qu'un trou et un dispositif associé, mais généralement, une pompe d'injection comporte deux trous 7 diamétralement opposés pour éviter au piston de subir des charges latérales dues à des poussées hydrauliques.Of course, the fuel injection pump may have only one hole and an associated device, but generally, an injection pump has two diametrically opposite holes 7 to prevent the piston from being subjected to lateral loads due to hydraulic thrusts. .

Le piston 10 comporte une gorge 11, une rainure verticale 12, une autre rainure verticale diamétralement opposée non représentée, un évidement 13 qui délimite une arête oblique 14 et un autre évidement délimitant une autre arête oblique, non représentés.The piston 10 has a groove 11, a vertical groove 12, another diametrically opposite vertical groove not shown, a recess 13 which delimits an oblique edge 14 and another recess delimiting another oblique edge, not shown.

Le piston 10 est mû verticalement dans le cylindre 2, par l'intermédiaire d'une came non représentée et exécute en montant une course de compression et en descendant une course d'aspiration. Par ailleurs une crémaillère, non représentée, engrène avec une denture d'une pièce reliée au piston, afin de positionner angulairement celui-ci et de modifier l'instant de la fin de l'injection par l'intermédiaire des arêtes ôbliques.The piston 10 is moved vertically in the cylinder 2, by means of a cam not shown and performs by mounting a compression stroke and descending a suction stroke. Furthermore, a rack, not shown, meshes with a toothing of a part connected to the piston, in order to angularly position the latter and to modify the instant of the end of the injection via the oblique edges.

Dans la figure 2, montrant le cylindre 2 muni d'un trou 7, il est représenté de manière plus détaillée, un dispositif 20 débouchant dans la chambre collectrice 6 en face d'un trou 7.In FIG. 2, showing the cylinder 2 provided with a hole 7, there is shown in more detail, a device 20 opening into the collecting chamber 6 opposite a hole 7.

Ce dispositif 20 est installé dans un corps tubulaire 21 comportant un alésage 36, une tête extérieure 22, par exemple à six pans, permettant le serrage de ce dispositif, un filetage 23 coopérant avec un taraudage 11 du corps de pompe 1, et une extrémité 24 munie d'un épaulement 25 formant butée. Un joint 40 est interposé entre la tête 22 et le corps de pompe 1.This device 20 is installed in a tubular body 21 comprising a bore 36, an external head 22, for example with a hexagon, allowing the tightening of this device, a thread 23 cooperating with a tapping 11 of the pump body 1, and one end 24 provided with a shoulder 25 forming a stop. A seal 40 is interposed between the head 22 and the pump body 1.

Bien entendu, la présence du corps tubulaire 21 n'est pas indispensable et l'alésage 36 avec l'épaulement 25 peuvent être obtenus directement par usinage du corps de pompe 1.Of course, the presence of the tubular body 21 is not essential and the bore 36 with the shoulder 25 can be obtained directly by machining the pump body 1.

Le dispositif 20 comprend un piston 26 mobile librement à l'intérieur de l'alésage 36, un bouchon 30 arrêté en translation par un anneau d'arrêt 32 et muni d'un joint torique 33 assurant l'étanchéité entre le bouchon 30 et l'alésage 36. Des cales 42 en nombre et épaisseur variables permettent de modifier la distance au repos entre le piston 26 et le bouchon 30. Un tube cylindrique 34 à paroi ondulé est relié d'une façon étanche au bouchon 30 et au piston 26 par l'intermédiaire des épaulements 31 et 28.The device 20 comprises a piston 26 freely movable inside the bore 36, a plug 30 stopped in translation by a stop ring 32 and provided with an O-ring 33 ensuring the seal between the plug 30 and the bore 36. Shims 42 in variable number and thickness make it possible to modify the distance at rest between the piston 26 and the plug 30. A cylindrical tube 34 with corrugated wall is tightly connected to the plug 30 and to the piston 26 by through the shoulders 31 and 28.

Le tube cylindrique 34 ainsi que l'épaulement 28 du piston 26 et l'épaulement 31 du piston 30, constituent une enceinte hermétiquement close et déformable située dans l'alésage 36 du corps tubulaire 21. Cette enceinte est limitée mécaniquement en expansion par l'épaulement 25 et l'anneau d'arrêt 32, et limitée mécaniquement en compression car chaque épaulement interne 28, 31 des pistons 26 et du bouchon 30 comporte une butée 28', 3 T. Ces deux butées servent également de guide à un ressort 35 qui est en appui sur les épaulements 28, 31. La présence de ce ressort n'est, bien entendu, pas indispensable car l'enceinte hermétiquement close et déformable contient un gaz sous pression, éventuellement accompagné d'un liquide pour modifier la raideur de l'amortisseur constitué uniquement par le gaz ou par l'ensemble gaz-ressort.The cylindrical tube 34 as well as the shoulder 28 of the piston 26 and the shoulder 31 of the piston 30 constitute a hermetically sealed and deformable enclosure located in the bore 36 of the tubular body 21. This enclosure is mechanically limited in expansion by the shoulder 25 and the stop ring 32, and mechanically limited in compression because each internal shoulder 28, 31 of the pistons 26 and of the plug 30 has a stop 28 ', 3 T. These two stops also serve as a guide for a spring 35 which is supported on the shoulders 28, 31. The presence of this spring is, of course, not essential because the hermetically sealed and deformable enclosure contains a pressurized gas, possibly accompanied by a liquid to modify the stiffness of the damper constituted solely by the gas or by the gas-spring assembly.

Le piston 26 comporte une paroi ou face externe 27, plane ou concave, avantageusement rendue résistante à l'abrasion par un traitement de surface approprié, tel le dépôt d'un matériau céramique. Le piston 26 étant en butée sur l'épaulement 25, cette face 27 doit se trouver à une distance du trou 7 n'excédant pas 1,5 fois le plus petit diamètre de ce trou.The piston 26 has an outer wall or face 27, flat or concave, advantageously made resistant to abrasion by an appropriate surface treatment, such as the deposition of a ceramic material. The piston 26 being in abutment on the shoulder 25, this face 27 must be at a distance from the hole 7 not exceeding 1.5 times the smallest diameter of this hole.

Le corps tubulaire 21 comporte un orifice 37 et le corps de pompe 1 comporte une rainure 38, cet orifice 37 et cette rainure 38 mettant en communication le volume 41 existant entre l'alésage 36, le tube 34, le piston 26 et le bouchon 30 avec la chambre collectrice 6. L'orifice 37 est réalisé à une distance 1 de la face 43 du piston 26 lorsqu'il est au repos sur l'épaulement 25. Cette distance 1 est légèrement inférieure à la distance L séparant au repos les deux butées 28' et 31' et ainsi, lorsque le piston 26 recule, l'obturation du trou 37, préalable à la mise en butée mécanique, provoque une montée en pression du combustible enfermé dans le volume 41 et assure une mise en butée hydraulique.The tubular body 21 has an orifice 37 and the pump body 1 has a groove 38, this orifice 37 and this groove 38 connecting the volume 41 existing between the bore 36, the tube 34, the piston 26 and the plug 30 with the collecting chamber 6. The orifice 37 is produced at a distance 1 from the face 43 of the piston 26 when it is at rest on the shoulder 25. This distance 1 is slightly less than the distance L separating the two at rest stops 28 ′ and 31 ′ and thus, when the piston 26 moves back, closing the hole 37, prior to the mechanical abutment, causes the fuel trapped in the volume 41 to increase in pressure and ensures hydraulic abutment.

Selon une variante de l'invention, un orifice 37' peut être pratiqué directement dans le piston 26 et, dans ce cas, la rainure 38 et le trou 37 ne sont pas indispensables.According to a variant of the invention, an orifice 37 'can be made directly in the piston 26 and, in this case, the groove 38 and the hole 37 are not essential.

Une opération d'amortissement et d'écrêtage se passe de la manière suivante :

  • - Au début de la phase de décompression, c'est-à-dire à l'instant où les arêtes 14 du piston 10 découvrent les trous 7, la quantité de mouvement disponible dans le combustible à la sortie du trou 7 est immédiatement retransformée, par l'intermédiaire du piston 26 qui comprime le gaz et/ou le ressort du dispositif 20, en énergie potentielle évitant ainsi aux ondes de pression de se propager à l'extérieur de la chambre collectrice 6. Le piston est ensuite repoussé par le gaz et/ou le ressort vers la butée 25. La libération progressive de l'énergie potentielle emmagasinée dans le dispositif 20 est contrôlée par l'échange d'une quantité de combustible entre le volume 41 et la chambre collectrice 6, à travers les orifices 37, 38 et/ou 37' et/ou le jeu installé entre le piston 26 et l'alésage 36.
A depreciation and clipping operation takes place as follows:
  • - At the start of the decompression phase, that is to say at the moment when the edges 14 of the piston 10 discover the holes 7, the amount of movement available in the fuel at the outlet of the hole 7 is immediately transformed, by means of the piston 26 which compresses the gas and / or the spring of the device 20, in potential energy thus preventing the pressure waves from propagating to the outside of the collecting chamber 6. The piston is then pushed back by the gas and / or the spring towards the stop 25. The progressive release of the potential energy stored in the device 20 is controlled by the exchange of a quantity of fuel between the volume 41 and the collecting chamber 6, through the orifices 37, 38 and / or 37 'and / or the clearance installed between the piston 26 and the bore 36.

La variation de volume de la chambre collectrice 6 engendrée par le déplacement du piston est comprise entre 10 et 30% de la cylindrée maximale de la pompe d'injection. Les cales 42 permettent d'ajuster au besoin la précontrainte du dispositif 20.The variation in volume of the collecting chamber 6 generated by the displacement of the piston is between 10 and 30% of the maximum displacement of the injection pump. The shims 42 make it possible to adjust the preload of the device 20 if necessary.

L'énergie cinétique est disponible à la sortie du trou 7 sous forme d'une faible masse de combustible animée d'une très grande vitesse. Le choc qui s'ensuit sur la face 27 du piston 26 engendre une érosion importante. L'utilisation d'un traitement approprié destiné à augmenter la résistance à l'abrasion de la face 27 permet de limiter les conséquences de ce phénomène.Kinetic energy is available at the outlet of hole 7 in the form of a small mass of fuel driven by a very high speed. The impact that ensues on the face 27 of the piston 26 generates significant erosion. The use of an appropriate treatment intended to increase the abrasion resistance of the face 27 makes it possible to limit the consequences of this phenomenon.

L'avantage d'utiliser une enceinte close et accumulatrice telle que le dispositif 20, évite d'avoir à réaliser entre le piston 26 et l'alésage 36 une étanchéité dont la durée de vie est aléatoire et qui introduit une perte par frottement importante. Cette perte par frottement vient s'ajouter, au moment de l'absorption de l'énergie cinétique, à l'inertie due à la masse du piston 26 dont la résistance au déplacement doit, au contraire, être très faible.The advantage of using a closed and accumulating enclosure such as the device 20, avoids having to achieve between the piston 26 and the bore 36 a seal whose lifetime is random and which introduces a significant friction loss. This friction loss is added, at the time of the absorption of the kinetic energy, to the inertia due to the mass of the piston 26 whose resistance to displacement must, on the contrary, be very low.

Claims (7)

1/ Procédé d'amortissement des ondes de pression hydrauliques et d'écrêtage des variations de pression dans les conduits d'alimentation d'une pompe hydraulique munie d'une chambre d'alimentation (6), consistant à transformer l'énergie potentielle emmagasinée dans le fluide en excès dans la chambre de travail (5) en énergie cinétique, caractérisé en ce que cette énergie cinétique est directement utilisée pour accroître temporairement le volume de la chambre d'alimentation d'une valeur comprise entre 10 et 30% de la cylindrée maximale de la pompe hydraulique.1 / Method for damping hydraulic pressure waves and clipping pressure variations in the supply conduits of a hydraulic pump provided with a supply chamber (6), consisting in transforming the stored potential energy in the excess fluid in the working chamber (5) in kinetic energy, characterized in that this kinetic energy is directly used to temporarily increase the volume of the supply chamber by a value between 10 and 30% of the maximum displacement of the hydraulic pump. 2/ Pompe hydraulique, permettant la mise en oeuvre du procédé selon la revendication 1, comportant une chambre d'alimentation (6) recevant le ou les conduits d'alimentation, un piston (10) à course rectiligne et constante à l'intérieur d'une chambre de travail (5), muni d'au moins une arête (14) réglant d'une manière sélectivement variable la fin du processus de refoulement hors de la pompe par coopération avec au moins un trou (7) mettant en communication la chambre de travail (5) avec la chambre d'alimentation (6), au moins un dispositif (20) d'amortissement des ondes de pression hydrauliques et d'écrêtage des variations de pression, constitué par une paroi (27) mobile élastiquement disposée normalement à la direction du jet de fluide, caractérisée en ce que la paroi (27) est située dans la chambre d'alimentation (6), dans l'axe d'un trou (7) et à proximité de ce trou à une distance n'excédant pas 1,5 fois le plus petit diamètre du trou.2 / Hydraulic pump, allowing the implementation of the method according to claim 1, comprising a supply chamber (6) receiving the supply duct (s), a piston (10) with rectilinear and constant stroke inside d '' a working chamber (5), provided with at least one edge (14) regulating in a selectively variable manner the end of the delivery process out of the pump by cooperation with at least one hole (7) connecting the working chamber (5) with the supply chamber (6), at least one device (20) for damping the hydraulic pressure waves and for clipping the pressure variations, constituted by an elastically arranged movable wall (27) normally to the direction of the fluid jet, characterized in that the wall (27) is located in the supply chamber (6), in the axis of a hole (7) and near this hole at a distance not exceeding 1.5 times the smallest diameter of the hole. 3/ Pompe hydraulique selon la revendication 2, caractérisée en ce que la paroi mobile (27) du dispositif fait partie d'une enceinte hermétiquement close et déformable, limitée mécaniquement en expansion et compression, et contenant un gaz sous pression accompagné éventuellement d'un liquide et/ou éventuellement d'un ressort (35).3 / Hydraulic pump according to claim 2, characterized in that the movable wall (27) of the device is part of a hermetically sealed and deformable enclosure, mechanically limited in expansion and compression, and containing a gas under pressure possibly accompanied by a liquid and / or possibly a spring (35). 4/ Pompe hydraulique selon la revendication 3, caractérisé en ce qu'une partie de l'enceinte déformable est constituée par un tube cylindrique (34) à paroi ondulée, les ondulations permettant une déformation suivant son axe.4 / hydraulic pump according to claim 3, characterized in that a part of the deformable enclosure is constituted by a cylindrical tube (34) with corrugated wall, the corrugations allowing deformation along its axis. 5/ Pompe hydraulique selon au moins l'une des revendications 2 à 4, caractérisée en ce que la paroi mobile (27) du dispositif constitue un piston de faible inertie obturant partiellement un logement (36) contenant l'enceinte, des rainures et/ou des trous (37) aménagés dans le piston ou dans la paroi du logement (36) mettant en communication le logement avec la chambre d'alimentation (6).5 / Hydraulic pump according to at least one of claims 2 to 4, characterized in that the movable wall (27) of the device constitutes a piston of low inertia partially closing a housing (36) containing the enclosure, grooves and / or holes (37) arranged in the piston or in the wall of the housing (36) putting the housing into communication with the supply chamber (6). 6/ Pompe hydraulique selon au moins l'une des revendications 2 à 5,' caractérisée en ce que des moyens (42) sont prévus pour faire varier la précontrainte du dispositif (20) d'amortissement et d'écrêtage.6 / Hydraulic pump according to at least one of claims 2 to 5, ' characterized in that means (42) are provided for varying the preload of the device (20) damping and clipping. 7/ Pompe hydraulique selon au moins l'une des revendications 2 à 6, caractérisée en ce que celle-ci est une pompe d'injection de combustible.7 / Hydraulic pump according to at least one of claims 2 to 6, characterized in that the latter is a fuel injection pump.
EP85103536A 1984-03-29 1985-03-26 Method for damping hydraulic pressure shocks or variations in the supply conduits of a hydraulic pump, and pump adapted thereto Withdrawn EP0157335A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8404904A FR2562165B1 (en) 1984-03-29 1984-03-29 METHOD AND DEVICE FOR DAMPING HYDRAULIC PRESSURE WAVES AND CLIPPING PRESSURE VARIATIONS IN THE SUPPLY DUCTS OF A FUEL INJECTION PUMP
FR8404904 1984-03-29

Publications (2)

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EP0157335A2 true EP0157335A2 (en) 1985-10-09
EP0157335A3 EP0157335A3 (en) 1987-05-06

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EP85103536A Withdrawn EP0157335A3 (en) 1984-03-29 1985-03-26 Method for damping hydraulic pressure shocks or variations in the supply conduits of a hydraulic pump, and pump adapted thereto

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US (1) US4591321A (en)
EP (1) EP0157335A3 (en)
JP (1) JPS60222570A (en)
FR (1) FR2562165B1 (en)

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AU707937B2 (en) * 1997-10-27 1999-07-22 Mitsubishi Denki Kabushiki Kaisha Cylinder injection high-pressure fuel pump
EP0947745A1 (en) * 1998-03-31 1999-10-06 Mitsubishi Denki Kabushiki Kaisha Sealing device for a high-pressure vessel

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US4714066A (en) * 1980-08-14 1987-12-22 Jordan Robert D Fuel injector system
JPH0740696Y2 (en) * 1987-06-12 1995-09-20 日本発条株式会社 Hydraulic pump device
DE4009745A1 (en) * 1990-03-27 1991-10-02 Man B & W Diesel Ag Fuel injection pump for Diesel engine - has spring-loaded pistons to ensure rapid build-up of fuel pressure
JP2884454B2 (en) * 1991-11-20 1999-04-19 株式会社ゼクセル Lead machining method of plunger for fuel injection pump
US5845621A (en) * 1997-06-19 1998-12-08 Siemens Automotive Corporation Bellows pressure pulsation damper
JP3471587B2 (en) * 1997-10-27 2003-12-02 三菱電機株式会社 High pressure fuel pump for in-cylinder injection
GB9920210D0 (en) * 1999-08-27 1999-10-27 Lucas Industries Ltd Fuel pump
JP2002089405A (en) * 2000-09-11 2002-03-27 Toyota Motor Corp High-pressure fuel system
US20040087897A1 (en) * 2002-07-31 2004-05-06 Birger Hjertman Device and method for liquid jet generation
SE0202350D0 (en) * 2002-07-31 2002-07-31 Pharmacia Ab Liquid jet generation device and method
US7610902B2 (en) * 2007-09-07 2009-11-03 Gm Global Technology Operations, Inc. Low noise fuel injection pump
EP2667012B1 (en) * 2012-05-25 2017-02-22 Caterpillar Motoren GmbH & Co. KG Baffle body with a wear resistant insert element and baffle body for a plunger operated fuel pump
DE102013012653B4 (en) * 2013-07-30 2015-02-19 L'orange Gmbh accumulator

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FR2356020A1 (en) * 1975-12-10 1978-01-20 Semt Pump peak pressure absorption system - varies volume available for fluid under control of pressure peaks themselves

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU707937B2 (en) * 1997-10-27 1999-07-22 Mitsubishi Denki Kabushiki Kaisha Cylinder injection high-pressure fuel pump
EP0947745A1 (en) * 1998-03-31 1999-10-06 Mitsubishi Denki Kabushiki Kaisha Sealing device for a high-pressure vessel
US6382456B1 (en) 1998-03-31 2002-05-07 Mitsubishi Denki Kabushiki Kaisha Sealing device for a high-pressure vessel

Also Published As

Publication number Publication date
FR2562165A1 (en) 1985-10-04
US4591321A (en) 1986-05-27
FR2562165B1 (en) 1988-06-17
JPS60222570A (en) 1985-11-07
EP0157335A3 (en) 1987-05-06

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