Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B7/00—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors
  • F15B7/005—With rotary or crank input
  • F15B7/006—Rotary pump input
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B7/00—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors
  • F15B7/008—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors with rotary output

Definitions

• the present invention relates to a hydraulic control device for a double-acting cylinder.
• Double-acting hydraulic cylinders are generally supplied with pressurized oil by an electro-hydraulic unit to which is added an oil distribution block comprising a hydraulic distributor or a set of valves controlling the operation of the cylinder in both directions, especially in the case of differential operation.
• the hydraulic cylinder is mounted in the immediate vicinity of the element whose movement it is to cause and it is connected, by flexible or rigid pipes, to the distribution block located at a distance, generally in the immediate vicinity of the electro-hydraulic unit.
• Such a hydraulic supply device has the disadvantage that, if the supply pipes of the jack are flexible, these pipes can break, the pressurized oil can leak out from the broken pipes, the jack is then no longer supplied and the load actuated by the jack is no longer maintained.
• the hydraulic connection circuit between the jack and the distribution block associated with the electro-hydraulic unit consists of rigid pipes
• the kinematics of the mobile assembly controlled by the jack must take account of the increase in size due the presence of the electro-hydraulic unit near the cylinder.
• the use of rigid pipes does not prevent any leaks from the distributor, which always appear when using a conventional drawer distributor.
• the present invention aims to remedy these drawbacks by providing a supply device hydraulics of particularly simple design, of a reduced size, effectively protecting, by design, the cylinder against bursting of the piping supplying it with oil under pressure or against a leak of the distributor.
• this hydraulic supply device for a double-acting cylinder comprising an electro-hydraulic unit supplying pressurized oil to the cylinder via a pipe and a distribution block
• the distribution block fixed to the body of the jack, directly or in the immediate vicinity thereof, by means of rigid connecting members, comprises: a non-return valve connected upstream to a supply pipe extending to the electro-hydraulic unit and, downstream, to the right chamber of the hydraulic cylinder, by an internal conduit to said block, said valve preventing any return of oil to the unit, or to the outside in case supply pipe rupture
• This cylinder 1 comprises a cylindrical body 2 inside which is slidably mounted a piston 3 integral with a piston rod 4 extending axially outside, through one end of the body 2 of the jack, to control the movement of a any load.
• the piston 3 delimits, inside the body 2 of the jack, two chambers, namely a straight chamber 2a . in which extends the piston rod 4, and a left chamber 2jb.
• the jack 1 is supplied with pressurized oil from an electro-hydraulic unit 5 comprising, in the usual manner, an oil pump 6 driven by an electric motor 7 and the suction port of which is connected, by the by means of a pipe to which a filter 8 is connected, to an oil tank 9.
• the electro-hydraulic unit 5 also includes a pipe 11 for returning oil to the tank 9.
• the circulation of the oil supplying the cylinder 1 is controlled by a distribution block 12 which is secured directly to the body 2 of the cylinder 1 or else in the immediate vicinity thereof, by means of organs. rigid connection 10.
• This distribution block 12 comprises:
• a first internal conduit 13 provided at one of its ends with a non-return valve 14, which is connected to the discharge port of the pump 6 via an external and flexible pipe 15, l 'other end of said conduit 13 directly supplying pressurized oil to the right chamber 2a. of the jack 1 on the one hand and, through a normally closed electromagnetic control valve 16, of the left chamber 2b of the jack 1 on the other hand, and
• the operation of the hydraulic supply device of the jack 1 is as follows: to cause the re-entry of the rod, that is to say its displacement from right to left in the drawing, the pump 6 of the electro-hydraulic unit 5 is started, which discharges oil under pressure, through the non-return valve 14 of the distribution block 12, in the right chamber 2a. of the jack 1.
• the excitation of the electromagnetic valve 18 which also passes into the open position is also controlled, the valve 16 remaining in its closed rest position.
• the pressurized oil arriving through the pipe 15 and the internal conduit 13 can then gradually fill the right chamber 2a. of the jack 2, while the oil in the left chamber 2b of this jack can return to the reservoir 9 by passing through the valve 18, in the open position, the internal conduit 17 and the piping 11 returning to the reservoir 9.
• valve 18 To cause the reverse movement, that is to say the exit of the piston rod 4, the valve 18 is kept in the closed position and the valve 16 is however excited to move it to the open position, which establishes communication between the two right chambers 2a. and left 2b of the jack 1.
• the oil under pressure coming from the electro-hydraulic unit 5 flows through the non-return valve 14, into the internal conduit 13 and from the latter towards the two chambers 2a . , 2b_ of the cylinder 1.
• the cylinder 1 is found to be protected by the non-return valve 14.
• the oil contained in the two chambers 2a. , 2b of the jack 1 cannot in fact flow outwards, through the broken pipe 15, due to the presence of the non-return valve 14 which forms a hermetic barrier.
• the distribution block 12 is protected from internal leaks unlike conventional distributors. The cylinder 1 cannot therefore empty its oil and this guarantees the operational safety of the cylinder 1, especially when it is used for moving heavy loads.
• the device according to one or other of the variants of the invention is advantageously usable in the particular field of the tailgate, in particular for a vehicle for which until now there has never been any such safety device and protection in the event of rupture of the pressurized fluid supply pipes.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Actuator (AREA)
• Fluid-Pressure Circuits (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9451112

Family Applications (1)

Country Status (5)

Cited By (4)

Citations (5)

• 1993
  • 1993-09-22 FR FR9311276A patent/FR2710372B1/fr not_active Expired - Lifetime
• 1994
  • 1994-09-22 AU AU77860/94A patent/AU7786094A/en not_active Abandoned
  • 1994-09-22 WO PCT/FR1994/001109 patent/WO1995008715A1/fr active IP Right Grant
  • 1994-09-22 DE DE69415559T patent/DE69415559D1/de not_active Expired - Lifetime
  • 1994-09-22 EP EP94928429A patent/EP0776426B1/de not_active Expired - Lifetime

Patent Citations (5)

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