Classifications

• • 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
  • B25D9/02—Portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously of the tool-carrier piston type, i.e. in which the tool is connected to an impulse member
• • 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
• • 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
  • B25D9/16—Valve arrangements therefor
  • B25D9/20—Valve arrangements therefor involving a tubular-type slide valve

Definitions

• the present invention relates to a pressure regulation device for a hydraulic percussion device.
• Hydraulic percussion devices of the rock breaker type, are generally equipped with a striking piston driven by a result of hydraulic forces which pushes it alternately in one direction then in the other, so as to strike a tool in contact with the material to be demolished.
• High power breakers are generally fitted with a device allowing the hydraulic fluid inlet pressure to be regulated to a predetermined value and adjustable so as to obtain the desired performance.
• the pressure for supplying hydraulic fluid is determined at the time of the design of the device, in order to give the piston the desired impact energy.
• low power breakers are generally not equipped with pressure regulating device. These devices are often fitted with a nozzle or throttle on the hydraulic breaker return circuit, so that the pressure reaches the desired value, or else are fitted with a pressure limiter which drifts towards the return circuit a part of the hydraulic fluid flow if the supply pressure exceeds the expected value.
• the object of the invention is to provide a pressure regulation device which makes it possible to obtain an inlet pressure for the hydraulic fluid, preset to a certain value.
• This device must be a simple and economical device which can be applied in particular to low-power breakers and whose structure consists of a set of cylindrical parts fitted into the bore of the body of the breaker.
• the device which it relates to is of the type comprising a body inside which is formed a bore having several zones of different diameters, in which is mounted a piston having several zones of different diameters, the bore and the piston delimiting several chambers connected to the hydraulic circuit, to ensure, under the action of a distributor, an alternating movement of the piston, which strikes on a tool.
• the piston in the bore of the body and concentrically with the piston are mounted two parts offset axially and between which is disposed a deformable washer, one of the parts being stationary and the other part being slidably mounted in the bore, and movable in the direction of the stationary part, under the action of the hydraulic fluid supply pressure, which is exerted on the face of the movable part turned on the side opposite to the stationary part, this displacement of the moving part causing a deformation of the elastic washer to create a passage of variable section on the return circuit of the hydraulic fluid to the reservoir, or on a circuit which drifts towards the return circuit part of the supply flow of the device, so as to regulate the inlet pressure.
• the elastic washer prevents any passage with the fluid return circuit, and blocks the operation of the rock breaker.
• the moving part moves, causing a deformation of the elastic washer, to create a passage to the return circuit, which has the effect of adjusting the supply pressure to a limit value.
• a channel in the stationary part is formed a channel, connected to the high pressure hydraulic fluid supply channel, directly or by an internal chamber, or, via the distributor, to a chamber partially delimited by the piston, set alternately at high and low pressure, this channel opening into the face of the stationary part turned towards the side of the moving part and on which the elastic washer rests, while a channel connected to the circuit back to the tank opens into an annular volume located on the side of the elastic washer opposite to that bearing against the stationary part.
• the two channels opening into the central bore do not communicate.
• this creates a passage of variable section which ensures the communication of these two channels.
• the moving part comprises, on the side of the stationary part, an annular recess delimiting a central nose intended to come to bear on the part of the elastic washer which is not in abutment against the part motionless.
• the elastic washer has a generally rectangular cross section, the underside of which presents, from the outside to the inside, a bearing heel on the stationary part, and a surface parallel to the heel and set back from the latter, connected by an edge to a surface inclined from the outside towards the inside and from the stationary part towards the moving part. The elastic washer is deformed by tilting around the edge.
• the elastic washer has a generally rectangular cross-section, and the part located radially inward of the wall of the stationary part serving as a support for the elastic washer, is inclined from the outside towards the inside and in the opposite direction to the moving part.
• the stationary part comprises an external annular rim whose internal diameter is slightly less than the external diameter of the elastic washer.
• the elastically deformable washer can be made of steel, in particular spring steel. If for reasons of simplicity, it is advantageous that the stationary part is separate from the body, it is also possible that it is an integral part of the body. In any case, the invention will be clearly understood, with the aid of the description which follows, with reference to the appended schematic drawing showing, by way of nonlimiting examples, several pressure regulation devices.
• Figure 1 is a longitudinal sectional view of a hydraulic percussion device equipped with a first device.
• Figure 2 is a partial view in longitudinal section and on an enlarged scale of the part of the apparatus comprising this first device.
• Figure 3 is a cross-sectional view on an enlarged scale of an elastic washer belonging to the regulating device shown in Figures 1 and 2.
• Figures 4 to 6 are three partial views in longitudinal section, showing the regulating device during three operating phases.
• Figures 7 and 8 are two partial sectional views, similar to Figures 4 to 6, showing a control device equipped with another washer, in two operating positions.
• Figure 9 is a partial sectional view, similar to Figure 7, showing another device, in the unpowered position of the device.
• Figure 10 is a longitudinal sectional view, similar to Figure 2, of a control device associated with a circuit which derives part of the supply flow of the device.
• Figure 11 is a longitudinal sectional view on an enlarged scale of the part of the apparatus comprising the device.
• Figures 12 and 13 are two partial views showing the position of the elastic washer ensuring regulation, respectively when the device is unpowered and during the power supply period of the device.
• Figure 1 shows, very schematically, a hydraulic percussion device comprising a body 2 in which is formed a central bore 3 in which is mounted a striking piston 4 driven by a reciprocating movement, striking the head of a tool 5.
• the high-pressure hydraulic fluid supply is marked with the reference A
• the return to the tank is marked with the reference R.
• the high pressure supply brings the fluid through a channel 6, which is connected to a hydraulic distributor 7, for controlling the movement.
• the channel 6 also feeds through a channel 8 a hydraulic accumulator 9, and a chamber 10 communicating with the accumulator 9 and located at the end of the body 2 opposite to that crossed by the tool.
• the conduit 6 also feeds through a channel 12, a chamber 13 for raising the striking piston.
• a chamber 14 is connected to the distributor 7.
• the piston 4 has different shoulders along its length, at the level of the various aforementioned chambers.
• the piston is propelled downward for its striking stroke.
• the upper chamber 14 is connected by channels 15, 16 to the low pressure network R of the installation.
• the bore 3, in which the piston 4 is housed contains a stationary annular part 17, partially delimiting the chamber 14.
• a movable part 18 the other end of which partially delimits the chamber 10.
• the low pressure circuit constituted by the channels 15, 16 passes through the two parts 17, 18 which are mounted concentrically with the piston. Between the two immobile and movable parts 17 and 18 is mounted an elastic washer 19. In the embodiment shown in FIGS.
• the washer 19 is delimited by three perpendicular faces, and a fourth lower face, comprising, outside inwards, a heel 20, a surface parallel to the heel 20 connected by an edge 22 to an inclined surface 23, in the embodiment shown in the drawing, from bottom to top and from the outside inwards .
• the elastic washer 19 can be made of different materials, including steel.
• the channel 15 coming from the distributor 17, is extended by a section of channel 24 inside the stationary part 17, and opens into the wall of this part turned upwards, in the zone thereof between the heel 20 and the edge 22. The return to the reservoir via the channel 16 takes place above the elastic washer 19, at the level of a recess 25 in the moving part 18.
• the parts When the the device is not supplied with pressurized hydraulic fluid, the parts occupy the position shown in detail in FIGS. 2 and 4.
• the elastic washer 19 is flat, it bears by its heel 20 on the stationary part 17 , and the moving part 18 is supported on its upper face, so that there is no communication between the channel 15 and the channel 16 back to the tank.
• the hydraulic pressure will increase in the accumulator 9 and the chamber 10, tending to move the moving part 18 in the direction of the stationary part 17.
• the washer 19 deforms, as shown in FIG. 5, without however ensuring communication between the channels 15 and 16.
• the elastic washer 19 deforms more and more, under the increasing force of the high pressure exerted on the movable part 18, which locally supports the upper face of the washer, the position of this support being offset inwards relative to the position of the heel 20 and the edge 22.
• This offset support generates an elastic deformation of the shape of the washer 19.
• the edge 22 comes to bear against the part stationary 17, as shown in Figure 6, a hydraulic passage 26 is formed between the channels 15 and 16. The discharge of the device is then released and the breaker can start to operate normally. The starting pressure is determined by this first level of deformation of the washer.
• variable constriction 26 whose dimension depends on the deformation of the elastic washer 19, therefore on the value of the high hydraulic pressure of the apparatus.
• the pressure drop on the discharge circuit 15, 16, created by the variable throttle 26 depends on the high pressure, and therefore makes it possible to regulate this pressure at a calculated value.
• the geometry of the washer is designed to deform by a known value, so as to obtain a hydraulic passage section through passage 26, corresponding to the pressure drop on the evacuation circuit, necessary for obtaining the desired high pressure value.
• Figures 7 and 8 show an alternative embodiment, in which the elastic washer 19 does not have an inclined surface 23, this inclined surface being replaced by a slope 27 formed on the end face of the stationary part 17, this slope being tilted up and down and from outside to inside.
• Figure 7 shows the washer when the device is not supplied
• Figure 8 shows the device during operation, with a hydraulic passage 26 of variable section.
• the deformation of the washer is made with its support on the slope 27.
• FIG. 9 represents another embodiment, in which the washer 19 has a rectangular section, the bearing surface 28 of the washer on the stationary part 17, being raised compared to the previous case, the starting pressure can be determined by the value of the clearance between this surface 28 of the support plane of the washer, and the upper end of the slope 27.
• FIGS 10 to 13 show another embodiment in which the same elements are designated by the same references as above.
• the elastic washer 19 is intended to create a variable constriction on a circuit which drifts directly towards the return circuit R part of the supply flow of the device.
• the channel 15 coming from the distributor 7 is directly connected to the conduit 16 for low pressure return to the tank.
• the channel 24 could be supplied directly from the high pressure supply, this is that is to say from the channel 6.
• the channel 24 could also, for a similar result, be connected to the upper chamber 14, then being alternately connected to the low pressure and then to the supply pressure, depending on the position of the distributor 7.
• the upper chamber 14 is constantly isolated from the channel 24 and the outlet channel 16, by the washer 19.
• the stationary part 17 comprises an enveloping rim 30 partially the outside diameter of the washer.
• the washer simply has, on its underside, and on the inside, an inclined face 32.
• the invention brings a great improvement to the existing technique, by providing a pressure regulation device, of simple structure, and of very efficient operation, which is particularly advantageous for the equipment of '' hydraulic percussion devices to be produced under economic conditions, and the structure consists of cylindrical parts fitted into the bore of the body.
• the invention is not limited to the sole embodiments of this device described above by way of examples, on the contrary it embraces all the variants.
• the shape of the elastic washer could be different or that the stationary part 17 could be an integral part of the body, without thereby departing from the scope of the invention.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• Automation & Control Theory (AREA)
• Percussive Tools And Related Accessories (AREA)
• Earth Drilling (AREA)
• Fluid-Pressure Circuits (AREA)
• Vehicle Body Suspensions (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=34610579

Family Applications (1)

Country Status (18)

Families Citing this family (8)

Family Cites Families (11)

• 2003
  • 2003-12-11 FR FR0314529A patent/FR2863671B1/fr not_active Expired - Fee Related
• 2004
  • 2004-12-02 BR BRPI0417398-8A patent/BRPI0417398A/pt not_active IP Right Cessation
  • 2004-12-02 US US10/579,233 patent/US7434503B2/en active Active
  • 2004-12-02 WO PCT/FR2004/003098 patent/WO2005065892A1/fr active IP Right Grant
  • 2004-12-02 ES ES04805618T patent/ES2298855T3/es active Active
  • 2004-12-02 DE DE602004011102T patent/DE602004011102T2/de active Active
  • 2004-12-02 CN CNB2004800365310A patent/CN100436074C/zh not_active Expired - Fee Related
  • 2004-12-02 DK DK04805618T patent/DK1691953T3/da active
  • 2004-12-02 AU AU2004311658A patent/AU2004311658A1/en not_active Abandoned
  • 2004-12-02 JP JP2006543578A patent/JP2007513786A/ja active Pending
  • 2004-12-02 KR KR1020067013131A patent/KR101089241B1/ko active IP Right Grant
  • 2004-12-02 EP EP04805618A patent/EP1691953B1/de active Active
  • 2004-12-02 AT AT04805618T patent/ATE382453T1/de not_active IP Right Cessation
  • 2004-12-02 CA CA002546267A patent/CA2546267A1/fr not_active Abandoned
  • 2004-12-02 PT PT04805618T patent/PT1691953E/pt unknown
• 2006
  • 2006-05-25 IL IL175952A patent/IL175952A0/en unknown
  • 2006-06-08 ZA ZA200604726A patent/ZA200604726B/xx unknown
  • 2006-07-10 NO NO20063204A patent/NO20063204L/no not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events