EP0256955B1 - Method and apparatus for adjusting the percussion parameters of the impacting piston of a non compressible fluid-actuated device - Google Patents

Method and apparatus for adjusting the percussion parameters of the impacting piston of a non compressible fluid-actuated device Download PDF

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Publication number
EP0256955B1
EP0256955B1 EP87420203A EP87420203A EP0256955B1 EP 0256955 B1 EP0256955 B1 EP 0256955B1 EP 87420203 A EP87420203 A EP 87420203A EP 87420203 A EP87420203 A EP 87420203A EP 0256955 B1 EP0256955 B1 EP 0256955B1
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EP
European Patent Office
Prior art keywords
chamber
pressure
piston
valve
fluid
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EP87420203A
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German (de)
French (fr)
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EP0256955A1 (en
Inventor
Jean Sylvain Comarmond
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Montabert SAS
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Montabert SAS
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Priority to AT87420203T priority Critical patent/ATE58082T1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25D—PERCUSSIVE TOOLS
    • B25D9/00—Portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously
    • B25D9/14—Control devices for the reciprocating piston
    • B25D9/26—Control devices for adjusting the stroke of the piston or the force or frequency of impact thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25D—PERCUSSIVE TOOLS
    • B25D9/00—Portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously
    • B25D9/14—Control devices for the reciprocating piston
    • B25D9/145—Control devices for the reciprocating piston for hydraulically actuated hammers having an accumulator

Definitions

  • the subject of the present invention is a method for regulating the percussion parameters of the striking piston of an apparatus driven by an incompressible fluid under pressure, and an apparatus for implementing this method.
  • Percussion devices driven by an incompressible fluid under pressure are supplied with fluid, so that the result of the hydraulic forces applied successively on the striking piston, displaces the latter alternately in one direction then in the other.
  • This apparatus comprises a striking piston mounted to slide in a body comprising a cylinder-shaped cavity, in which is concentrically mounted a distributor ensuring a controlled supply of fluid under pressure so that the result of the forces is applied successively to the piston to move it one way and then the other.
  • devices of this type must be adjusted according to the hardness of the ground encountered by the tool.
  • the piston moves inside a bore or cylinder in which is provided, above the piston, a chamber which, delimited in part by the latter, is conventionally called: upper room.
  • a chamber which, delimited in part by the latter, is conventionally called: upper room.
  • this chamber is supplied with pressurized fluid, the hydraulic force which is created there allows the piston to describe its stroke.
  • a second chamber is formed, also partially delimited by the piston, conventionally called: lower chamber.
  • the striking piston can, in the instant following the impact against the tool, rebound more or less depending on the hardness of the ground. If the piston rebounds on the tool just after impact, the speed of the piston can be such that it generates a momentary overpressure in the upper chamber and a momentary decrease in pressure in the lower chamber.
  • the first consists in equipping the device with a regulator making it possible to adjust the supply pressure of pressurized fluid, which modifies the speed of impact.
  • Another solution consists in equipping the apparatus with a hydraulically actuated distributor, making it possible to modify the striking stroke, and consequently, the displacement and the impact speed of the piston.
  • the impact parameters such as impact speed and striking frequency, are at most manually adjustable using complex devices, but in no case do they allow automatic adaptation of the impact speed to the nature of the terrain in which the tool operates.
  • the present invention aims to remedy these drawbacks.
  • the regulation process which it relates to, intended for a percussion device driven by an incompressible fluid under pressure, comprising two upper and lower chambers formed in the cylinder in which the piston moves and equipped with devices for controlling the parameters of percussion, impact speed and striking frequency, allowing adjustment according to the hardness of the ground in which the device must work, is characterized in that it consists in measuring, at least during the possible rebound time of the impact piston on the tool, the pressure in the upper chamber, in the lower chamber or in a chamber connected to one of them, to compare this pressure to a reference pressure, then according to this comparison , to regulate the flow of fluid in a channel connected to the device for controlling the percussion parameters.
  • An apparatus for implementing this process of the type comprising a piston which can be moved alternately inside the cylinder, with which it delimits an upper chamber and a lower chamber, under the action of the resultant of hydraulic forces exerted successively in the upper and lower chambers, and equipped with hydraulically controllable devices capable of varying percussion parameters, impact speed and striking frequency, is characterized in that it comprises a channel opening directly into the upper chamber, or into the lower chamber, or in a chamber in communication with one of them at the time of impact, connected via a hydraulic element to means for controlling the device for controlling the percussion parameters.
  • the device represented in FIG. 1 is a percussion device of the type described in the request. of French patent 81.14043 (FR-A 2 509 217) or its European correspondent EP-A 0 070 246 in the name of the Applicant, and comprising a piston 1 sliding in a body 2 comprising a cylinder-shaped cavity, in which is concentrically mounted a distributor 3.
  • This device is equipped with a regulator making it possible to adjust the supply pressure of the device and, consequently, the speed of impact of the piston.
  • this regulator comprises a drawer 4 in equilibrium under the force of a spring 5 and under the pressure of the supply fluid, brought by a channel 6 and a nozzle 7, acting in the chamber 8 at the end of the drawer .
  • a chamber 9 for piloting the drawer is located so as to act in an antagonistic manner to the effect of the pressure in the chamber 8.
  • the drawer 4 delimits with the walls of the cavity in which it is mounted, a throttled passage forming a nozzle 10 ensuring the passage of the fluid discharged through the channel 11 by the piston, during the return stroke thereof.
  • the back pressure created by the nozzle 10 is such that the supply pressure acting in the chamber 8 rises to the value necessary to compensate for the action of the spring 5, and this in the absence of pressure in the chamber 9.
  • a channel 12 opens into a chamber 13 called “upper chamber”, formed inside the cylinder in which the piston 1 moves, and partly delimited by it.
  • a sequence valve 14 ensuring the comparison between the pressure of the fluid contained in the upper chamber 13 and the pressure of the supply fluid under high pressure, the pressurized feed fluid being supplied from the channel 31 to the sequence valve through a channel 17.
  • This sequence valve allows the passage of fluid in a channel 15, when the pressure in the upper chamber is greater than the supply pressure of the device.
  • This sequence valve 14 is connected via a channel 15 to a device comprising a slide 16 mounted to slide in a bore 18 delimiting on one side a chamber 19 called “buffer chamber” into which the channel 15 opens and the other side a chamber 20, connected to the low pressure circuit 22 via a channel 23.
  • the chamber 20 also contains a spring tending to move the slide in a direction of reduction of the volume of the buffer chamber 19.
  • the chambers 19 and 20 are in communication with each other by means of a nozzle 25.
  • the buffer chamber 19 is also connected to the piloting chamber 9 of the pressure regulator by a channel 24.
  • the communication between the buffer chamber 19 and the low pressure circuit 22 by the nozzle 25 and the chamber 20 allows, under these conditions, the pressure of the chamber 19 to remain low.
  • the rebound speed of the piston on the latter is high, which generates, in the upper chamber 13, a pressure higher than the supply pressure of the device, due to the sudden discharge of fluid through the channels normally used to supply the upper chamber during the stroke.
  • the overpressure in the channel 12 actuates the sequence valve 14 which injects, into the buffer chamber 19 and through a nozzle 26 mounted on the channel 15, a certain quantity of fluid increasing the pressure in the chamber 19 and in the piloting chamber 9 of the regulator.
  • the slide valve 4 of the regulator tends to further throttle the nozzle 10, which results in an increase in the operating pressure of the device and in an increase in the speed of impact of the piston.
  • the slide 16 is in equilibrium for a pressure in the buffer chamber 19 such that the flow of fluid that this pressure allows to pass through the nozzle 25 is equal to the flow injected through the nozzle 26 by the valve of sequence 14.
  • the upper chamber 13 is connected either to the supply channel 31 or to the low pressure channel 22.
  • the control chamber 29 of the distributor 28 is supplied with pressurized fluid through a channel 32 opening into an annular recess delimited by a groove 33 of a drawer 34 slidably mounted in a bore 35.
  • the groove 33 is susceptible, depending on the position of the drawer 34, to put the chamber 29 in communication via the channel 32 with one or more of a series of channels 36-39 opening into the cylinder in which the piston moves.
  • the function of the drawer 34 is to select the active control channel 36-39 which, supplied from the lower chamber 40, will pressurize the control section 29.
  • the supply of pressurized fluid to the upper chamber intervenes more or less early in the piston operating cycle, varying the stroke, the striking frequency and the impact speed of the piston.
  • the control of the position of the drawer 34 is obtained, as in the previous embodiment, by means of a channel 12 opening into the upper chamber 13 and of a valve. sequence 14 which supplies the buffer chamber 19 with fluid delimited in part by the drawer 34.
  • the rebound is zero as well as the amount of fluid injected into the buffer chamber 19, which allows the drawer 34, pushed by the spring 21, to select a channel 36-39 corresponding to a striking stroke. lower and a decrease in impact speed.
  • FIG. 3 represents a variant of the apparatus of FIG. 2 in which the channel 12 is equipped with a non-return valve 43 allowing the passage of fluid only from the chamber 13 towards the chamber 19, and in which the chamber 20 , located on the other side of the drawer 34 relative to the chamber 19, is in communication via a channel 17 with the source of pressurized fluid.
  • the non-return valve 43 When the pressure in the chamber 13 is higher than the supply pressure, a certain quantity of fluid can flow through the channel 12, the non-return valve 43 and the channel 15 in the buffer chamber 19.
  • the non-return valve return avoids a flow of fluid from the chamber 19 to the upper chamber when the latter is connected by the distributor 28 to the low pressure channel 22 during the return stroke of the piston.
  • the slide valve 34 is in equilibrium for a pressure in the buffer chamber 19 such that the flow rate which this pressure allows to pass during each cycle in the nozzle 25 is equal to the pulsed flow rate coming from the upper chamber 13 through the nozzle 26.
  • FIG. 4 represents a variant of the apparatus of FIG. 2 in which the channel 12 no longer opens into the upper chamber 13, but into the lower chamber 40.
  • this channel 12 is arranged a sequence valve which, when the pressure at the interior of the lower chamber 40, becomes lower than the pressure for supplying pressurized fluid supplied to the valve through the channel 17, makes it possible to inject into the buffer chamber 19 through the nozzle 26 a certain quantity of fluid supplied through channel 17.
  • the apparatus advantageously comprises, on the channel 47 for supplying the lower chamber 40 with pressurized fluid, a non-return valve 45 allowing free passage of the reflux fluid from the chamber 40 to the channel d 'supply 31.
  • a nozzle 46 mounted on a bypass channel 48, makes it possible to supply the chamber 40 with pressurized fluid to obtain the ascent of the piston 1.
  • the slide valve 34 is in equilibrium for a pressure in the chamber 19 such that the flow rate which this pressure passes through the nozzle 25 is equal to the pulsed flow rate injected by the sequence valve 44 into the buffer chamber 19.
  • the sequence valve 44 injects fluid at the supply pressure into the chamber 19, which increases the pressure inside the latter, and causes the slide to move. against the action of spring 21.
  • the slide 34 discovers control channels 36 to 39 supplying the distributor 28 in a direction of increase in the stroke and the impact speed of the impact piston.
  • the rebound is zero as well as the amount of fluid to be injected into the buffer chamber, which allows the drawer 34 to occupy a position selecting a channel 36 to 39 corresponding to a lower striking stroke.
  • This element 53 relates the high pressure supply channel 31 to the lower chamber 40 when the pressure of the chamber 40 drops below a predetermined value or when the difference between the supply pressure and the pressure of the chamber 40 exceeds a predetermined value.
  • This element 53 therefore makes it possible to maintain a minimum pressure in the chamber 40 avoiding any cavitation in the latter.
  • FIG. 6 represents another variant of this device in which the channel 12 always opens into the lower chamber 40.
  • This channel 12 is equipped with a non-return valve 49 oriented so as to make the passage of fluid from the chamber 40 impossible. towards chamber 19 and allowing only reverse circulation.
  • the chamber 20, located on the other side of the drawer 34, is connected to the duct 31 for supplying fluid under high pressure by a channel 17.
  • the slide valve 34 is in equilibrium for a pressure in the buffer chamber 19, such that the flow rate coming from the chamber 20 via the nozzle 25 is equal to the pulsed flow rate which this pressure allows to evacuate into the chamber 40 through the nozzle 26 and the non-return valve 49.
  • the invention brings a great improvement to the existing technique by providing a method and a device of simple design ensuring an automatic adjustment of the impact parameters to the hardness of the ground in which the tool works.
  • the measurement of the momentary pressure variation following the rebound of the piston on the tool could be carried out by a pressure tap not in the upper chamber or in the lower chamber, as indicated above, but in a chamber communicating with one or the other of these, at the moment of impact and rebound of the piston on the tool.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • Automation & Control Theory (AREA)
  • Percussive Tools And Related Accessories (AREA)
  • Placing Or Removing Of Piles Or Sheet Piles, Or Accessories Thereof (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Supply Devices, Intensifiers, Converters, And Telemotors (AREA)
  • Fluid-Damping Devices (AREA)
  • Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
  • Earth Drilling (AREA)

Abstract

A hydraulic percussion device comprises a housing defining a longitudinal cylinder, a piston longitudinally reciprocal in the cylinder and subdividing same into a front compartment and a rear compartment, and a tool engageable longitudinally with the piston at the front compartment. The compartments are alternately and oppositely hydraulically pressurized to move the piston forward to strike the tool while traveling at an end speed and to move the piston backward away from the tool, the rate of alternation being a frequency parameter and the speed being a force parameter. A controller varies at least one of the parameters by detecting how much the piston rebounds from the tool after striking same and operating the control means in accordance with how much rebound is detected. How much the piston rebounds can be detected by sensing the pressure in one of the compartments immediately after the piston strikes the tool. As rebound increases the pressure in the rear compartment increases relative to a set point or pressure in the front compartment decreases relative to a set point, and vice versa. Rebound can also be detected by sensing the pressure in one of the compartments and at one of the sides of the source and operating the control means in accordance with the differential between these sensed pressures.

Description

La présente invention a pour objet un procédé de régulation des paramètres de percusion du piston de frappe d'un appareil mû par un fluide incompressible sous pression, et un appareil pour la mise en oeuvre de ce procédé.The subject of the present invention is a method for regulating the percussion parameters of the striking piston of an apparatus driven by an incompressible fluid under pressure, and an apparatus for implementing this method.

Les appareils à percussion mus par un fluide incompressible sous pression sont alimentés en fluide, de telle manière que la résultante des forces hydrauliques s'appliquant successivement sur le piston de frappe, déplace celui-ci alternativement dans un sens puis dans l'autre.Percussion devices driven by an incompressible fluid under pressure are supplied with fluid, so that the result of the hydraulic forces applied successively on the striking piston, displaces the latter alternately in one direction then in the other.

Un appareil de ce type est décrit dans le document EP-A 0 070 246.An apparatus of this type is described in document EP-A 0 070 246.

Cet appareil comprend un piston de frappe monté coulissant dans un corps comportant une cavité en forme de cylindre, dans laquelle est monté concentriquement un distributeur assurant une alimentation contrôlée en fluide sous pression de telle sorte que la résultante des forces s'applique successivement sur le piston pour déplacer celui-ci dans un sens puis dans l'autre.This apparatus comprises a striking piston mounted to slide in a body comprising a cylinder-shaped cavity, in which is concentrically mounted a distributor ensuring a controlled supply of fluid under pressure so that the result of the forces is applied successively to the piston to move it one way and then the other.

Pour permettre l'obtention d'un rendement optimal et pour la bonne tenue à l'usure et à la fatigue de l'outil, les appareils de ce type doivent être réglés en fonction de la dureté du terrain rencontré par l'outil.To enable optimum performance to be obtained and for good resistance to wear and fatigue of the tool, devices of this type must be adjusted according to the hardness of the ground encountered by the tool.

Il est connu que, pour une puissance globale donnée, il est préférable de privilégier l'énergie par coup par rapport à la fréquence de frappe lorsque l'outil rencontre un terrain dur, tandis qu'il est préférable de privilégier la fréquence de frappe par rapport à l'énergie par coup lorsque l'outil rencontre un terrain tendre.It is known that, for a given overall power, it is preferable to favor the energy per stroke over the impact frequency when the tool encounters hard ground, while it is preferable to favor the impact frequency by relative to the energy per blow when the tool encounters soft ground.

Dans les appareils de ce type, le piston se déplace à l'intérieur d'un alésage ou cylindre dans lequel est ménagée, au-dessus du piston, une chambre qui, délimitée pour partie par celui-ci, est appelée de façon conventionnelle : chambre haute. Lorsque cette chambre est alimentée en fluide sous pression, la force hydraulique, qui y est créée, permet au piston de décrire sa course de frappe. A l'autre extrémité de l'alésage dans lequel se déplace le piston, est ménagée une seconde chambre, également délimitée pour partie par le piston, appelée de façon conventionnelle: chambre basse.In devices of this type, the piston moves inside a bore or cylinder in which is provided, above the piston, a chamber which, delimited in part by the latter, is conventionally called: upper room. When this chamber is supplied with pressurized fluid, the hydraulic force which is created there allows the piston to describe its stroke. At the other end of the bore in which the piston moves, a second chamber is formed, also partially delimited by the piston, conventionally called: lower chamber.

La force résultant de la pression de fluide dans la chambre basse assure le déplacement du piston pour sa course de retour.The force resulting from the fluid pressure in the lower chamber ensures the displacement of the piston for its return stroke.

Il est également connu que le piston de frappe peut, dans l'instant suivant le choc contre l'outil, rebondir plus ou moins suivant la dureté du terrain. En cas de rebond du piston sur l'outil juste après l'impact, la vitesse du piston peut être telle qu'elle génère une surpression momentanée dans la chambre haute et une diminution momentanée de pression dans la chambre basse.It is also known that the striking piston can, in the instant following the impact against the tool, rebound more or less depending on the hardness of the ground. If the piston rebounds on the tool just after impact, the speed of the piston can be such that it generates a momentary overpressure in the upper chamber and a momentary decrease in pressure in the lower chamber.

Pour ajuster la vitesse d'impact du piston, deux techniques sont couramment utilisées. La première consiste à équiper l'appareil d'un régulateur permettant d'ajuster la pression d'alimentation en fluide sous pression, ce qui modifie la vitesse d'impact.Two techniques are commonly used to adjust the impact speed of the piston. The first consists in equipping the device with a regulator making it possible to adjust the supply pressure of pressurized fluid, which modifies the speed of impact.

Une autre solution consiste à équiper l'appareil d'un distributeur actionné hydrauliquement, permettant de modifier la course de frappe, et par suite, la cylindrée et la vitesse d'impact du piston.Another solution consists in equipping the apparatus with a hydraulically actuated distributor, making it possible to modify the striking stroke, and consequently, the displacement and the impact speed of the piston.

Les paramètres de percussion, tels que vitesse d'impact et fréquence de frappe, sont tout au plus réglables manuellement à l'aide de dispositifs complexes, mais ne permettent en aucun cas une adaptation automatique de la vitesse d'impact à la nature du terrain dans lequel évolue l'outil.The impact parameters, such as impact speed and striking frequency, are at most manually adjustable using complex devices, but in no case do they allow automatic adaptation of the impact speed to the nature of the terrain in which the tool operates.

La présente invention vise à remédier à ces inconvénients.The present invention aims to remedy these drawbacks.

A cet effet, le procédé de régulation qu'elle concerne, destiné à un appareil à percussion mû par un fluide incompressible sous pression, comprenant deux chambres haute et basse ménagées dans le cylindre dans lequel se déplace le piston et équipé de dispositifs de commande des paramètres de percussion, vitesse d'impact et fréquence de frappe, permettant un réglage en fonction de la dureté du terrain dans lequel l'appareil doit travailler, est caractérisé en ce qu'il consiste à mesurer, au moins pendant la durée de rebond éventuel du piston de frappe sur l'outil, la pression dans la chambre haute, dans la chambre basse ou dans une chambre reliée à l'une de celles-ci, à comparer cette pression à une pression de référence, puis en fonction de cette comparaison, à régler l'écoulement de fluide dans un canal relié au dispositif de commande des paramètres de percussion.To this end, the regulation process which it relates to, intended for a percussion device driven by an incompressible fluid under pressure, comprising two upper and lower chambers formed in the cylinder in which the piston moves and equipped with devices for controlling the parameters of percussion, impact speed and striking frequency, allowing adjustment according to the hardness of the ground in which the device must work, is characterized in that it consists in measuring, at least during the possible rebound time of the impact piston on the tool, the pressure in the upper chamber, in the lower chamber or in a chamber connected to one of them, to compare this pressure to a reference pressure, then according to this comparison , to regulate the flow of fluid in a channel connected to the device for controlling the percussion parameters.

Un appareil pour la mise en oeuvre de ce procédé, du type comprenant un piston déplaçable alternativement à l'intérieur du cylindre, avec lequel il délimite une chambre haute et une chambre basse, sous l'action de la résultante de forces hydrauliques exercées successivement dans les chambres haute et basse, et équipé de dispositifs pilotables hydrauliquement susceptibles de faire varier des paramètres de percussion, vitesse d'impact et fréquence de frappe, est caractérisé en ce qu'il comporte un canal débouchant directement dans la chambre haute, ou dans la chambre basse, ou encore dans une chambre en communication avec l'une de celles-ci au moment de l'impact, relié par l'intermédiaire d'un élément hydraulique à des moyens de pilotage du dispositif de commande des paramètres de percussion.An apparatus for implementing this process, of the type comprising a piston which can be moved alternately inside the cylinder, with which it delimits an upper chamber and a lower chamber, under the action of the resultant of hydraulic forces exerted successively in the upper and lower chambers, and equipped with hydraulically controllable devices capable of varying percussion parameters, impact speed and striking frequency, is characterized in that it comprises a channel opening directly into the upper chamber, or into the lower chamber, or in a chamber in communication with one of them at the time of impact, connected via a hydraulic element to means for controlling the device for controlling the percussion parameters.

De toute façon l'invention, sera bien comprise à l'aide de la description qui suit, en référence au dessin schématique annexé, représentant, à titre d'exemples non limitatifs, plusieurs formes d'exécution de cet appareil:

  • Figure 1 est une vue en coupe longitudinale d'un premier appareil équipé d'un régulateur de pression;
  • Figures 2 à 4 sont trois vues en coupe longitudinale de trois variantes de cet appareil équipé d'un distributeur hydraulique d'admission du fluide sous pression ;
  • Figure 5 est une vue de détail et à échelle agrandie d'une variante de l'appareil de figure 4 ;
  • Figure 6 est une vue en coupe longitudinale d'une autre forme d'exécution de cet appareil équipé d'un distributeur.
In any case, the invention will be clearly understood with the aid of the description which follows, with reference to the appended schematic drawing, representing, by way of non-limiting examples, several embodiments of this device:
  • Figure 1 is a longitudinal sectional view of a first device equipped with a pressure regulator;
  • Figures 2 to 4 are three views in longitudinal section of three variants of this device equipped with a hydraulic distributor for admitting the pressurized fluid;
  • Figure 5 is a detail view and on an enlarged scale of a variant of the apparatus of Figure 4;
  • Figure 6 is a longitudinal sectional view of another embodiment of this device equipped with a distributor.

L'appareil représenté à la figure 1 est un appareil à percussion du type de celui décrit dans la demande le brevet français 81.14043 (FR-A 2 509 217) ou son correspondant européen EP-A 0 070 246 au nom de la Demanderesse, et comprenant un piston 1 coulissant dans un corps 2 comportant une cavité en forme de cylindre, dans laquelle est monté concentriquement un distributeur 3.The device represented in FIG. 1 is a percussion device of the type described in the request. of French patent 81.14043 (FR-A 2 509 217) or its European correspondent EP-A 0 070 246 in the name of the Applicant, and comprising a piston 1 sliding in a body 2 comprising a cylinder-shaped cavity, in which is concentrically mounted a distributor 3.

Cet appareil est équipé d'un régulateur permettant d'ajuster la pression d'alimentation de l'appareil et, par conséquent, la vitesse d'impact du piston.This device is equipped with a regulator making it possible to adjust the supply pressure of the device and, consequently, the speed of impact of the piston.

A cet effet, ce régulateur comporte un tiroir 4 en équilibre sous la force d'un ressort 5 et sous la pression du fluide d'alimentation, amené par un canal 6 et un gicleur 7, agissant dans la chambre 8 d'extrémité du tiroir. Une chambre 9 de pilotage du tiroir est située de façon à agir de manière antagoniste à l'effet de la pression dans la chambre 8.To this end, this regulator comprises a drawer 4 in equilibrium under the force of a spring 5 and under the pressure of the supply fluid, brought by a channel 6 and a nozzle 7, acting in the chamber 8 at the end of the drawer . A chamber 9 for piloting the drawer is located so as to act in an antagonistic manner to the effect of the pressure in the chamber 8.

Le tiroir 4 délimite avec les parois de la cavité dans laquelle il est monté, un passage étranglé formant un gicleur 10 assurant le passage du fluide refoulé à travers le canal 11 par le piston, lors de la course de retour de celui-ci.The drawer 4 delimits with the walls of the cavity in which it is mounted, a throttled passage forming a nozzle 10 ensuring the passage of the fluid discharged through the channel 11 by the piston, during the return stroke thereof.

La contre-pression créée par le gicleur 10 est telle que la pression d'alimentation agissant dans la chambre 8 monte à la valeur nécessaire pour compenser l'action du ressort 5, et ceci en l'absence de pression dans la chambre 9.The back pressure created by the nozzle 10 is such that the supply pressure acting in the chamber 8 rises to the value necessary to compensate for the action of the spring 5, and this in the absence of pressure in the chamber 9.

Conformément à l'invention, un canal 12 débouche dans une chambre 13 dénommée "chambre haute", ménagée à l'intérieur du cylindre dans lequel se déplace le piston 1, et délimitée pour partie par celui-ci.According to the invention, a channel 12 opens into a chamber 13 called "upper chamber", formed inside the cylinder in which the piston 1 moves, and partly delimited by it.

Sur le canal 12 est montée une valve de séquence 14 assurant la comparaison entre la pression du fluide contenu dans la chambre haute 13 et la pression du fluide d'alimentation sous haute pression, le fluide d'alimen tation sous pression étant amené depuis le canal 31 à la valve de séquence par un canal 17. Cette valve de séquence autorise le passage de fluide dans un canal 15, lorsque la pression dans la chambre haute est supérieure à la pression d'alimentation de l'appareil.On the channel 12 is mounted a sequence valve 14 ensuring the comparison between the pressure of the fluid contained in the upper chamber 13 and the pressure of the supply fluid under high pressure, the pressurized feed fluid being supplied from the channel 31 to the sequence valve through a channel 17. This sequence valve allows the passage of fluid in a channel 15, when the pressure in the upper chamber is greater than the supply pressure of the device.

Cette valve de séquence 14 est reliée par l'intermédiaire d'un canal 15 à un dispositif comprenant un tiroir 16 monté coulissant dans un alésage 18 délimitant d'un côté une chambre 19 appelée "chambre tampon" dans laquelle débouche le canal 15 et de l'autre côté une chambre 20, reliée au circuit basse pression 22 par l'intermédiaire d'un canal 23. La chambre 20 contient également un ressort tendant à déplacer le tiroir dans une sens de réduction du volume de la chambre tampon 19.This sequence valve 14 is connected via a channel 15 to a device comprising a slide 16 mounted to slide in a bore 18 delimiting on one side a chamber 19 called "buffer chamber" into which the channel 15 opens and the other side a chamber 20, connected to the low pressure circuit 22 via a channel 23. The chamber 20 also contains a spring tending to move the slide in a direction of reduction of the volume of the buffer chamber 19.

Les chambres 19 et 20 sont en communication l'une avec l'autre par l'intermédiaire d'un gicleur 25. La chambre tampon 19 est également reliée à la chambre de pilotage 9 du régulateur de pression par un canal 24.The chambers 19 and 20 are in communication with each other by means of a nozzle 25. The buffer chamber 19 is also connected to the piloting chamber 9 of the pressure regulator by a channel 24.

Dans la mesure où l'appareil travaille dans un terrain tendre, la vitesse de rebond du piston sur l'outil est nulle ou très faible. La pression régnant dans la chambre haute 13 à l'instant suivant la frappe du piston sur l'outil, ne dépasse donc pas sensiblement la valeur de la pression d'alimentation en fluide sous pression de l'appareil. La valve de séquence 14 n'injecte donc pas de fluide dans le canal 15.Since the device works in soft ground, the rebound speed of the piston on the tool is zero or very low. The pressure prevailing in the upper chamber 13 at the instant following the striking of the piston on the tool, therefore does not substantially exceed the value of the pressure for supplying fluid under pressure to the device. The sequence valve 14 therefore does not inject fluid into the channel 15.

La communication entre la chambre tampon 19 et le circuit basse pression 22 par le gicleur 25 et la chambre 20, permet, dans ces conditions, à la pression de la chambre 19 de rester basse.The communication between the buffer chamber 19 and the low pressure circuit 22 by the nozzle 25 and the chamber 20 allows, under these conditions, the pressure of the chamber 19 to remain low.

Il en est de même pour la pression régnant dans la chambre de pilotage 9 du régulateur de pression, dont le tiroir 4 reste dans une position telle que le gicleur 10 est largement ouvert, ce qui permet d'obtenir une faible pression de fonctionnement de l'appareil et, par suite, une faible vitesse d'impact du piston de frappe.It is the same for the pressure prevailing in the piloting chamber 9 of the pressure regulator, the slide 4 of which remains in a position such that the nozzle 10 is widely open, which makes it possible to obtain a low operating pressure of the 'apparatus and, therefore, a low impact speed of the impact piston.

Si au contraire, le terrain rencontré par l'outil est dur, la vitesse de rebond du piston sur ce dernier est importante, ce qui génère, dans la chambre haute 13, une pression supérieure à la pression d'alimentation de l'appareil, due au brusque refoulement de fluide à travers les canaux servant normalement à alimenter la chambre haute pendant la course de frappe. La surpression dans le canal 12 actionne la valve de séquence 14 qui injecte, dans la chambre tampon 19 et à travers un gicleur 26 monté sur la canal 15, une certaine quantité de fluide augmentant la pression dans la chambre 19 et dans la chambre de pilotage 9 du régulateur. Le tiroir 4 du régulateur a tendance à étrangler davantage le gicleur 10, ce qui se traduit par une augmentation de la pression de fonctionnement de l'appareil et par une augmentation de la vitesse d'impact du piston.If on the contrary, the ground encountered by the tool is hard, the rebound speed of the piston on the latter is high, which generates, in the upper chamber 13, a pressure higher than the supply pressure of the device, due to the sudden discharge of fluid through the channels normally used to supply the upper chamber during the stroke. The overpressure in the channel 12 actuates the sequence valve 14 which injects, into the buffer chamber 19 and through a nozzle 26 mounted on the channel 15, a certain quantity of fluid increasing the pressure in the chamber 19 and in the piloting chamber 9 of the regulator. The slide valve 4 of the regulator tends to further throttle the nozzle 10, which results in an increase in the operating pressure of the device and in an increase in the speed of impact of the piston.

Il doit être noté que le tiroir 16 est en équilibre pour une pression dans la chambre tampon 19 telle que le débit de fluide que cette pression permet de faire passer par le gicleur 25 soit égal au débit injecté à travers le gicleur 26 par la valve de séquence 14.It should be noted that the slide 16 is in equilibrium for a pressure in the buffer chamber 19 such that the flow of fluid that this pressure allows to pass through the nozzle 25 is equal to the flow injected through the nozzle 26 by the valve of sequence 14.

Dans la forme d'exécution représentée à la figure 1, il est possible de limiter la pression de la chambre 19 à une valeur maximale par l'intermédiaire d'un clapet de décharge 50 taré à la pression voulue, et susceptible de mettre en communication la chambre 19 avec le canal 23 relié au réseau basse pression, par l'intermédiaire de deux canaux 51 et 52 disposés, respectivement, en amont et en aval du clapet.In the embodiment shown in FIG. 1, it is possible to limit the pressure of the chamber 19 to a maximum value by means of a relief valve 50 calibrated at the desired pressure, and capable of establishing communication the chamber 19 with the channel 23 connected to the low pressure network, via two channels 51 and 52 arranged, respectively, upstream and downstream of the valve.

Dans la forme d'exécution représentée à la figure 2, dans laquelle les mêmes éléments sont désignés par les mêmes références que précédemment, l'alternance des forces hydrauliques appliquées au piston de frappe est obtenue par l'intermédiaire d'un distributeur 28 de type connu et qui n'est de ce fait pas décrit ci-après.In the embodiment shown in FIG. 2, in which the same elements are designated by the same references as above, the alternation of the hydraulic forces applied to the striking piston is obtained by means of a distributor 28 of the type known and which is therefore not described below.

Selon la pression régnant dans la chambre de pilotage 29 de ce distributeur, la chambre haute 13 est reliée soit au canal d'alimentation 31 soit au canal basse pression 22.Depending on the pressure prevailing in the control chamber 29 of this distributor, the upper chamber 13 is connected either to the supply channel 31 or to the low pressure channel 22.

La chambre de pilotage 29 du distributeur 28 est alimentée en fluide sous pression par un canal 32 débouchant dans un évidement annulaire délimité par une gorge 33 d'un tiroir 34 monté coulisant dans un alésage 35. La gorge 33 est susceptible, en fonction de la position du tiroir 34, de mettre en communication la chambre 29 par l'intermédiaire du canal 32 avec un ou plusieurs d'une série de canaux 36-39 débouchant dans le cylindre dans lequel se déplace le piston. La fonction du tiroir 34 est de sélectionner le canal de commande actif 36-39 qui, alimenté à partir de la chambre basse 40, mettra sous pression la section de commande 29.The control chamber 29 of the distributor 28 is supplied with pressurized fluid through a channel 32 opening into an annular recess delimited by a groove 33 of a drawer 34 slidably mounted in a bore 35. The groove 33 is susceptible, depending on the position of the drawer 34, to put the chamber 29 in communication via the channel 32 with one or more of a series of channels 36-39 opening into the cylinder in which the piston moves. The function of the drawer 34 is to select the active control channel 36-39 which, supplied from the lower chamber 40, will pressurize the control section 29.

Selon le canal 36-39 sélectionné, l'alimentation en fluide sous pression de la chambre haute intervient plus ou moins tôt dans le cycle de fonctionnement du piston, faisant varier la course, la fréquence de frappe et la vitesse d'impact du piston.Depending on the channel 36-39 selected, the supply of pressurized fluid to the upper chamber intervenes more or less early in the piston operating cycle, varying the stroke, the striking frequency and the impact speed of the piston.

Selon la caractéristique essentielle de l'invention, la commande de la position du tiroir 34 est obtenue, comme dans la forme d'exécution précédente, par l'intermédiaire d'un canal 12 débouchant dans la chambre haute 13 et d'une valve de séquence 14 qui alimente en fluide la chambre tampon 19 délimitée pour partie par le tiroir 34.According to the essential characteristic of the invention, the control of the position of the drawer 34 is obtained, as in the previous embodiment, by means of a channel 12 opening into the upper chamber 13 and of a valve. sequence 14 which supplies the buffer chamber 19 with fluid delimited in part by the drawer 34.

Le fonctionnement de cet appareil est le suivant :The operation of this device is as follows:

Si le terrain rencontré par l'outil devient plus dur, le rebond du piston sur celui-ci augmente à l'issue de l'impact, ce qui se traduit par une augmentation de la pression dans la chambre haute à une valeur supérieure à la valeur de pression d'alimentation de l'appareil.If the ground encountered by the tool becomes harder, the rebound of the piston on it increases after impact, which results in an increase in the pressure in the upper chamber to a value greater than the supply pressure value of the device.

Il en résulte une ouverture de la valve de séquence 14 qui va permettre d'injecter une certaine quantité de fluide amené par le canal 17 dans ia chambre tampon 19, ce qui se traduit par une augmentation de la pression dans cette chambre tampon et un déplacement du tiroir 34 à l'encontre de l'action du ressort 21. Il en résulte une augmentation de la course de frappe et de la vitesse d'impact.This results in an opening of the sequence valve 14 which will make it possible to inject a certain quantity of fluid supplied by the channel 17 into the buffer chamber 19, which results in an increase in the pressure in this buffer chamber and a displacement of the drawer 34 against the action of the spring 21. This results in an increase in the striking stroke and the impact speed.

Si le terrain devient plus tendre, le rebond est nul ainsi que la quantité de fluide injectée dans la chambre tampon 19, ce qui permet au tiroir 34, poussé par le ressort 21, de sélectionner un canal 36-39 correspondant à une course de frappe plus faible et à une diminution de la vitesse d'impact.If the ground becomes softer, the rebound is zero as well as the amount of fluid injected into the buffer chamber 19, which allows the drawer 34, pushed by the spring 21, to select a channel 36-39 corresponding to a striking stroke. lower and a decrease in impact speed.

La figure 3 représente une variante de l'appareil de figure 2 dans laquelle le canal 12 est équipé d'un clapet anti-retour 43 ne permettant le passage de fluide que de la chambre 13 vers la chambre 19, et dans laquelle la chambre 20, située de l'autre côté du tiroir 34 par rapport à la chambre 19, est en communication par l'intermédiaire d'un canal 17 avec la source de fluide sous pression.FIG. 3 represents a variant of the apparatus of FIG. 2 in which the channel 12 is equipped with a non-return valve 43 allowing the passage of fluid only from the chamber 13 towards the chamber 19, and in which the chamber 20 , located on the other side of the drawer 34 relative to the chamber 19, is in communication via a channel 17 with the source of pressurized fluid.

Lorsque la pression dans la chambre 13 est supérieure à la pression d'alimentation, une certaine quantité de fluide peut s'écouler à travers le canal 12, le clapet anti-retour 43 et le canal 15 dans la chambre tampon 19. Le clapet anti-retour évite un écoulement de fluide de la chambre 19 vers la chambre haute lorsque celle-ci est reliée par le distributeur 28 au canal basse pression 22 lors de la course de retour du piston.When the pressure in the chamber 13 is higher than the supply pressure, a certain quantity of fluid can flow through the channel 12, the non-return valve 43 and the channel 15 in the buffer chamber 19. The non-return valve return avoids a flow of fluid from the chamber 19 to the upper chamber when the latter is connected by the distributor 28 to the low pressure channel 22 during the return stroke of the piston.

Le tiroir 34 est en équilibre pour une pression dans la chambre tampon 19 telle que le débit que cette pression permet de faire passer au cours de chaque cycle dans le gicleur 25 soit égal au débit pulsé provenant de la chambre haute 13 travers le gicleur 26.The slide valve 34 is in equilibrium for a pressure in the buffer chamber 19 such that the flow rate which this pressure allows to pass during each cycle in the nozzle 25 is equal to the pulsed flow rate coming from the upper chamber 13 through the nozzle 26.

En terrain dur, plus la pression dans la chambre 19 est importante, plus le tiroir 34 aura tendance à se déplacer à l'encontre du ressort 21 en sélectionnant un canal actif 36-39 permettant d'augmenter la course de frappe et donc la vitesse d'impact du piston.In hard ground, the higher the pressure in the chamber 19, the more the drawer 34 will tend to move against the spring 21 by selecting an active channel 36-39 making it possible to increase the striking stroke and therefore the speed piston impact.

La figure 4 représente une variante de l'appareil de figure 2 dans laquelle le canal 12 débouche non plus dans la chambre haute 13, mais dans la chambre basse 40. Sur ce canal 12 est disposée une valve de séquence qui, lorsque la pression à l'intérieur de la chambre basse 40, devient inférieure à la pression d'alimentation en fluide sous pression amené à la valve par le canal 17, permet d'injecter dans la chambre tampon 19 à travers le gicleur 26 une certaine quantité de fluide amenée par le canal 17.FIG. 4 represents a variant of the apparatus of FIG. 2 in which the channel 12 no longer opens into the upper chamber 13, but into the lower chamber 40. On this channel 12 is arranged a sequence valve which, when the pressure at the interior of the lower chamber 40, becomes lower than the pressure for supplying pressurized fluid supplied to the valve through the channel 17, makes it possible to inject into the buffer chamber 19 through the nozzle 26 a certain quantity of fluid supplied through channel 17.

Dans ce cas, l'appareil comporte, avantageusement, sur le canal 47 d'alimentation de la chambre basse 40 en fluide sous pression, un clapet anti-retour 45 permettant un libre passage du fluide de reflux de la chambre 40 vers le canal d'alimentation 31. Un gicleur 46, monté sur un canal de dérivation 48, permet de réaliser l'alimentation de la chambre 40 en fluide sous pression pour obtenir la remontée du piston 1.In this case, the apparatus advantageously comprises, on the channel 47 for supplying the lower chamber 40 with pressurized fluid, a non-return valve 45 allowing free passage of the reflux fluid from the chamber 40 to the channel d 'supply 31. A nozzle 46, mounted on a bypass channel 48, makes it possible to supply the chamber 40 with pressurized fluid to obtain the ascent of the piston 1.

Dans ce cas, le tiroir 34 est en équilibre pour une pression dans la chambre 19 telle que le débit que cette pression fait passer par le gicleur 25 soit égal au débit pulsé injecté par la valve de séquence 44 dans la chambre tampon 19.In this case, the slide valve 34 is in equilibrium for a pressure in the chamber 19 such that the flow rate which this pressure passes through the nozzle 25 is equal to the pulsed flow rate injected by the sequence valve 44 into the buffer chamber 19.

Si la dureté du terrain augmente, la vitesse et la durée du rebond augmentent. Durant cette période, le débit passant par le gicleur 46 est inférieur au débit nécessaire à l'augmentation de volume de la chambre 40, ce qui se traduit par une diminution de la pression dans cette chambre, et dans le canal 12. La pression devenant inférieure à la pression d'alimentation, la valve de séquence 44 injecte du fluide à la pression d'alimentation dans la chambre 19, ce qui augmente la pression à l'intérieur de celle-ci, et provoque le déplacement du tiroir à l'encontre de l'action du ressort 21.If the hardness of the ground increases, the speed and duration of the rebound increase. During this period, the flow rate passing through the nozzle 46 is lower than the flow rate necessary for the increase in volume of the chamber 40, which results in a reduction of the pressure in this chamber, and in the channel 12. The pressure becoming lower than the supply pressure, the sequence valve 44 injects fluid at the supply pressure into the chamber 19, which increases the pressure inside the latter, and causes the slide to move. against the action of spring 21.

Il en résulte que le tiroir 34 découvre des canaux de commande 36 à 39 alimentant le distributeur 28 dans un sens d'augmentation de la course et de la vitesse d'impact du piston de frappe.As a result, the slide 34 discovers control channels 36 to 39 supplying the distributor 28 in a direction of increase in the stroke and the impact speed of the impact piston.

Se le terrain est tendre, le rebond est nul ainsi que la quantité de fluide à injecter dans la chambre tampon, ce qui permet au tiroir 34 d'occuper une position sélectionnant un canal 36 à 39 correspondant à une course de frappe plus faible.If the ground is soft, the rebound is zero as well as the amount of fluid to be injected into the buffer chamber, which allows the drawer 34 to occupy a position selecting a channel 36 to 39 corresponding to a lower striking stroke.

Pour éviter les effets néfastes dus à la cavitation dans la chambre basse 40 au moment du rebond du piston, il est possible, comme montré à la figure 5, de disposer en dérivation du clapet 45 et du gicleur 46 un élément hydraulique 53 tel qu'un clapet anti-retour avec ressort ou valve de séquence.To avoid the harmful effects due to cavitation in the lower chamber 40 when the piston rebounds, it is possible, as shown in FIG. 5, to have a hydraulic element 53 such as bypass of the valve 45 and of the nozzle 46 a non-return valve with spring or sequence valve.

Cet élément 53 met en relation le canal d'alimentation haute pression 31 avec la chambre basse 40 lorsque la pression de la chambre 40 chute au-dessous d'une valeur prédéterminée ou lorsque la différence entre la pression d'alimentation et la pression de la chambre 40 dépasse une valeur prédéterminée.This element 53 relates the high pressure supply channel 31 to the lower chamber 40 when the pressure of the chamber 40 drops below a predetermined value or when the difference between the supply pressure and the pressure of the chamber 40 exceeds a predetermined value.

Cet élément 53 permet donc de maintenir une pression minimale dans la chambre 40 évitant toute cavitation dans celle-ci.This element 53 therefore makes it possible to maintain a minimum pressure in the chamber 40 avoiding any cavitation in the latter.

La figure 6 représente une autre variante de cet appareil dans laquelle le canal 12 débouche toujours dans la chambre basse 40. Ce canal 12 est équipé d'un clapet anti-retour 49 orienté de façon à rendre impossible le passage de fluide de la chambre 40 vers la chambre 19 et permettant seulement la circulation inverse.FIG. 6 represents another variant of this device in which the channel 12 always opens into the lower chamber 40. This channel 12 is equipped with a non-return valve 49 oriented so as to make the passage of fluid from the chamber 40 impossible. towards chamber 19 and allowing only reverse circulation.

Dans cette disposition, la chambre 20, située de l'autre côté du tiroir 34, est reliée au conduit 31 d'alimentation en fluide sous haute pression par un canal 17.In this arrangement, the chamber 20, located on the other side of the drawer 34, is connected to the duct 31 for supplying fluid under high pressure by a channel 17.

Le tiroir 34 est en équilibre pour une pression dans la chambre tampon 19, telle que le débit provenant de la chambre 20 par l'intermédiaire du gicleur 25 soit égal au débit pulsé que cette pression permet d'évacuer dans la chambre 40 à travers le gicleur 26 et le clapet anti-retour 49.The slide valve 34 is in equilibrium for a pressure in the buffer chamber 19, such that the flow rate coming from the chamber 20 via the nozzle 25 is equal to the pulsed flow rate which this pressure allows to evacuate into the chamber 40 through the nozzle 26 and the non-return valve 49.

Plus le terrain est dur, plus longue est la période pendant laquelle la pression à l'intérieur de la chambre basse 40 est inférieure à la pression de la chambre tampon 19, et plus grande est la quantité de fluide évacué de la chambre tampon, ce qui correspond à un déplacement du tiroir 34 à l'encontre de l'action du ressort 21, et à une sélection des canaux 36 à 39 correspondant à une augmentation de la course et de la vitesse d'impact du piston.The harder the ground, the longer the period during which the pressure inside the lower chamber 40 is lower than the pressure of the buffer chamber 19, and the greater the quantity of fluid discharged from the buffer chamber, this which corresponds to a movement of the slide 34 against the action of the spring 21, and to a selection of the channels 36 to 39 corresponding to an increase in the stroke and the impact speed of the piston.

Comme il ressort de ce qui précède, l'invention apporte une grande amélioration à la technique existante en fournissant un procédé et un appareil de conception simple assurant un réglage automatique des paramètres de percussion à la dureté du terrain dans lequel travaille l'outil.As is apparent from the above, the invention brings a great improvement to the existing technique by providing a method and a device of simple design ensuring an automatic adjustment of the impact parameters to the hardness of the ground in which the tool works.

Comme il va de soi, l'invention ne se limite pas aux seules formes d'exécution de cet appareil, décrites ci-dessus à titre d'exemples ; elle en embrasse, au contraire, toutes les variantes de réalisation.It goes without saying that the invention is not limited to the sole embodiments of this device, described above by way of examples; on the contrary, it embraces all of its variant embodiments.

C'est ainsi notamment que la mesure de la variation de pression momentanée consécutive au rebond du piston sur l'outil pourrait être effectuée par une prise de pression non pas dans la chambre haute ou dans la chambre basse, comme indiqué précédemment, mais dans une chambre communiquant avec l'une ou l'autre de celles-ci, au moment de l'impact et du rebond du piston sur l'outil.Thus, in particular, the measurement of the momentary pressure variation following the rebound of the piston on the tool could be carried out by a pressure tap not in the upper chamber or in the lower chamber, as indicated above, but in a chamber communicating with one or the other of these, at the moment of impact and rebound of the piston on the tool.

Claims (11)

1. A method of adjusting the percussion parameters of a non-compressible fluid-actuated percussion device, including two upper and lower chambers formed in the cylinder in which the piston moves and equipped with devices for controlling the percussion, speed of impact and frequency of impact parameters, permitting adjustment as a function of the hardness of the ground in which the device has to work, characterised in that it consists in measuring, at least during the duration of the possible rebound of the impacting piston on the tool, the pressure in the upper chamber, in the lower chamber or in a chamber connected to one of these, in comparing this pressure with a reference pressure, then, as a function of this comparison, in adjusting the flow of fluid in a conduit connected to the percussion parameter control device.
2. Apparatus for carrying out the method of Claim 1, of the type including a piston (1) reciproca- bly movable within the cylinder, with which it delimits an upper chamber (13) and a lower chamber (40), under the action of the resultant of hydraulic forces exerted successively in the upper and lower chambers, and equipped with hydraulically controlled devices capable of causing variations in the percussion, speed of impact and frequency of impact parameters, characterised in that it has a conduit (12) opening directly into the upper chamber (13), or into the lower chamber (40), or again into a chamber in communication at the moment of piston impact and rebound with one of these, connected by means of an hydraulic element (14, 43, 44, 49) for comparing the -pressure with a reference pressure to means for controlling the percussion parameter control device.
3. Percussion apparatus according to Claim 2, characterised in that the means for controlling the percussion parameter control device has a buffer chamber (19), one of the walls of which is delimited by a slide-valve (16, 34) enabling a stablised pressure to be created from the fluid injected into the conduit (12), the value of which pressure depends on the resistance to the penetration of the tool into the ground, and which is used to control the percussion parameter control devices.
4. Percussion apparatus according to Claim 3, characterised in that it has a conduit (12) opening, on the one hand, into the upper chamber (13) and, on the other hand, into the buffer chamber (15), on which is disposed a sequence valve ensuring the supply of fluid to the buffer chamber from the supply pressure of the device when the pressure within the upper chamber is greater than the supply pressure of the apparatus, in that the buffer chamber (19) communicates with the control chamber (9) of a pressure regulator, and, by means of a calibrated orifice (25) forming a restriction, with the low pressure circuit of the apparatus.
5. Percussion apparatus according to Claim 3, characterised in that the slide-valve (34) delimiting in part the buffer chamber (19) is slidably mounted in a cylinder into which open several axially offset channels (36-39), which also open into the cylinder (1) guiding the piston, the slide-valve (34) having a peripheral groove (33), capable, as a function of the position of the slide-valve, of being placed in communication with one or other of the conduits (36-39) which are themselves in communication with the high pressure supply system by means of a groove formed in the impact piston, another conduit (32) opening into the bore (35) opposite to the annular volume formed by the groove (33) of the slide-valve (34), which remains in permanent communication with this volume and which is connected to the main distributor (28) of the apparatus.
6. Percussion apparatus according to Claim 5, characterised in that the channel (12) opens into the upper chamber (13) and is equipped with a sequence valve (14) ensuring, through a calibrated orifice such as a restriction (26), the supply of fluid under pressure to the buffer chamber (19) from the supply pressure of the apparatus, when the pressure in the upper chamber is greater than the supply pressure and in that the chamber (20), located on the other side of the slide-valve (34) and communicating with the chamber (19) through a calibrated orifice such as a restriction (25), is connected to the low pressure system (22).
7. Apparatus according to Claim 5, characterised in that the conduit (12) opens into the upper chamber (13) and is equipped with a non-return valve (43) allowing the flow of fluid only from the upper chamber (13) towards the buffer chamber (19), through a calibrated orifice such as a restriction (26), and in that the chamber (20), located on the other side of the slide-valve (34) and communicating with the buffer chamber (19) by means of a calibrated orifice (25) in the form of a restriction, is connected to the pressure supply circuit (31) of the apparatus.
8. Apparatus according to Claim 5, characterised in that the conduit (12) opens into the lower chamber (40) and is equipped with a sequence valve (44) allowing, through a calibrated orifice such as a restriction (26), the supply to the buffer chamber (19) of fluid from the supply pressure of the apparatus when the pressure in the chamber (40) is lower than the supply pressure, and in that the chamber (20), located on the other side of the slide-valve (34), is connected to the low pressure circuit (22) of the apparatus.
9. Apparatus according to Claim 8, characterised in that the conduit (47) supplying fluid under pressure to the lower chamber has two conduits bypassing one another, of which one (48) equipped with a restriction (46) allows the supply to the chamber of fluid under pressure and of which the other equipped with a non-return valve (45) allows the flow of fluid from the lower chamber (40) towards the conduit supplying fluid under pressure.
10. Apparatus according to Claim 9, characterised in that it includes a hydraulic element (53), such as a non-return valve with a spring, or a sequence valve, disposed so as to by-pass the non-return valve (45) and the restriction (46), placing the fluid supply conduit (31) in communication with the lower chamber (40), when the pressure in this latter falls below a predetermined value, or when the difference between the supply pressure and the pressure in the lower chamber (40) exceeds a predetermined value.
11. Apparatus according to Claim 5, characterised in that the conduit (12) opens into the lower chamber (40) and is equipped with a non-return valve (49) allowing, through a calibrated orifice such as a restriction (26), the flow of fluid from the buffer chamber (19) towards the lower chamber (40), and in that the chamber (20), located on the other side of the slide-valve (34) and communicating with the buffer chamber (19) by means of a calibrated orifice (25) forming a restriction, is connected to the pressure fluid supply system of the apparatus.
EP87420203A 1986-08-07 1987-07-27 Method and apparatus for adjusting the percussion parameters of the impacting piston of a non compressible fluid-actuated device Expired - Lifetime EP0256955B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT87420203T ATE58082T1 (en) 1986-08-07 1987-07-27 METHOD AND DEVICE FOR ADJUSTING THE IMPACT PARAMETERS OF THE IMPACT PISTON OF AN INCOMPRESSible FLUID DRIVEN DEVICE.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8611710 1986-08-07
FR8611710A FR2602448B1 (en) 1986-08-07 1986-08-07 METHOD FOR REGULATING THE PERCUSSION PARAMETERS OF THE STRIKE PISTON OF AN APPARATUS MOVED BY AN INCOMPRESSIBLE PRESSURE FLUID, AND APPARATUS FOR CARRYING OUT SAID METHOD

Publications (2)

Publication Number Publication Date
EP0256955A1 EP0256955A1 (en) 1988-02-24
EP0256955B1 true EP0256955B1 (en) 1990-11-07

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EP87420203A Expired - Lifetime EP0256955B1 (en) 1986-08-07 1987-07-27 Method and apparatus for adjusting the percussion parameters of the impacting piston of a non compressible fluid-actuated device

Country Status (12)

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US (1) US4800797A (en)
EP (1) EP0256955B1 (en)
JP (1) JPS63174884A (en)
AT (1) ATE58082T1 (en)
AU (1) AU610513B2 (en)
CA (1) CA1295533C (en)
DE (2) DE256955T1 (en)
ES (1) ES2018292B3 (en)
FI (1) FI92477C (en)
FR (1) FR2602448B1 (en)
NO (1) NO165180C (en)
ZA (1) ZA875789B (en)

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ATE154774T1 (en) * 1989-10-18 1997-07-15 Mauro Vitulano METHOD FOR AUTOMATICALLY ADJUSTING THE FUNCTIONAL PARAMETERS OF AN IMPACT APPARATUS
ES2024251A6 (en) * 1990-05-14 1992-02-16 Tapias Puig Marcelino Improvements to the manufacture of hydraulic hammers.
DE4019019A1 (en) * 1990-06-14 1991-12-19 Krupp Maschinentechnik METHOD FOR DETERMINING CHARACTERISTIC CHARACTERISTICS OF A STRIKE AND DEVICE FOR IMPLEMENTING THE METHOD
DE4036918A1 (en) * 1990-11-20 1992-05-21 Krupp Maschinentechnik METHOD FOR ADAPTING THE OPERATIONAL BEHAVIOR OF A STRIKE TO THE HARDNESS OF THE CRUSHING MATERIAL AND DEVICE FOR IMPLEMENTING THE METHOD
FR2676953B1 (en) * 1991-05-30 1993-08-20 Montabert Ets HYDRAULIC PERCUSSION APPARATUS.
JP3378029B2 (en) * 1991-08-08 2003-02-17 丸善工業株式会社 Hydraulic breaker
ES2065806B1 (en) * 1992-03-11 1997-07-01 Tapias Puig Marcelino IMPROVEMENTS INTRODUCED IN HYDRAULIC HAMMERS.
FI104959B (en) 1994-06-23 2000-05-15 Sandvik Tamrock Oy Hydraulic impact hammer
FR2727891B1 (en) 1994-12-08 1997-01-24 Montabert Ets METHOD AND APPARATUS FOR REGULATING THE STRIKING STROKE OF A PERCUSSION APPARATUS MOUSED BY AN INCOMPRESSIBLE PRESSURE FLUID
FI104960B (en) * 1995-07-06 2000-05-15 Sandvik Tamrock Oy Hydraulic hammer
FI104961B (en) * 1996-07-19 2000-05-15 Sandvik Tamrock Oy Hydraulic impact hammer
EP0919339A1 (en) * 1996-07-25 1999-06-02 Komatsu Ltd. Hydraulically operated breaker with lost-motion prevention device
DE19838838A1 (en) * 1998-08-27 2000-03-02 Delmag Maschinenfabrik Diesel ram
FI121219B (en) * 2001-10-18 2010-08-31 Sandvik Tamrock Oy Method and apparatus for monitoring the operation of the impactor and for adjusting the operation of the impactor
JP2005177899A (en) * 2003-12-17 2005-07-07 Konan Electric Co Ltd Hydraulic hammering device
SE527921C2 (en) * 2004-10-20 2006-07-11 Atlas Copco Rock Drills Ab percussion
FR2902684B1 (en) 2006-06-27 2010-02-26 Montabert Roger METHOD FOR SWITCHING THE STROKE STROKE OF A MU-PERCUSSION APPARATUS BY AN INCOMPRESSIBLE FLUID UNDER PRESSURE, AND APPARATUS FOR CARRYING OUT SAID METHOD
SE530524C2 (en) * 2006-09-13 2008-07-01 Atlas Copco Rock Drills Ab Percussion, rock drilling machine including such percussion and method for controlling percussion
JP4729012B2 (en) * 2007-07-12 2011-07-20 有限会社名隆化学 Pachinko machine ball tray
CA2810914A1 (en) * 2010-09-10 2012-03-15 Rockdrill Services Australia Pty Ltd Improved rock drill
FR2983760B1 (en) 2011-12-09 2014-08-15 Montabert Roger METHOD FOR SWITCHING THE STROKE STROKE OF A STRIPPER PISTON OF A PERCUSSION APPARATUS
DE102013207860B4 (en) 2013-04-30 2017-06-22 MTU Aero Engines AG Method for operating a pneumatic needler and associated pneumatic needler
FR3027543B1 (en) * 2014-10-28 2016-12-23 Montabert Roger PERCUSSION APPARATUS
US9840000B2 (en) * 2014-12-17 2017-12-12 Caterpillar Inc. Hydraulic hammer having variable stroke control
US20160199969A1 (en) * 2015-01-12 2016-07-14 Caterpillar Inc. Hydraulic hammer having variable stroke control
US20160221171A1 (en) * 2015-02-02 2016-08-04 Caterpillar Inc. Hydraulic hammer having dual valve acceleration control system
KR101709673B1 (en) * 2016-12-13 2017-03-09 대모 엔지니어링 주식회사 2 step auto stroke type hydraulic breaker
FI128135B (en) * 2017-10-20 2019-10-31 Pneumaxpert Oy Arrangement with oscillating cylinder
FR3077753B1 (en) * 2018-02-14 2020-01-31 Montabert METHOD FOR ADJUSTING THE STRIKING STROKE OF A STRIKING PISTON OF A PERCUSSION APPARATUS, AND A PERCUSSION APPARATUS FOR CARRYING OUT SAID METHOD
CN108331582B (en) * 2018-03-16 2024-02-02 王代朋 Full-hydraulic stone mining machine

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Also Published As

Publication number Publication date
JPH0585311B2 (en) 1993-12-07
FR2602448A1 (en) 1988-02-12
FI92477C (en) 1994-11-25
EP0256955A1 (en) 1988-02-24
CA1295533C (en) 1992-02-11
NO873291L (en) 1988-02-08
FI873351A0 (en) 1987-08-03
DE256955T1 (en) 1988-06-09
FI873351A (en) 1988-02-08
FI92477B (en) 1994-08-15
NO873291D0 (en) 1987-08-06
ES2018292B3 (en) 1991-04-01
AU610513B2 (en) 1991-05-23
NO165180C (en) 1991-01-09
DE3766043D1 (en) 1990-12-13
JPS63174884A (en) 1988-07-19
FR2602448B1 (en) 1988-10-21
AU7662087A (en) 1988-02-11
US4800797A (en) 1989-01-31
ZA875789B (en) 1988-04-27
ATE58082T1 (en) 1990-11-15
NO165180B (en) 1990-10-01

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