FR2486870A1 - OVERLOAD SECURITY SYSTEM FOR LINEAR RUNNING PRESSES, ESPECIALLY FOR AUTOMATIC CUTTING PRESSES WITH ROD CONTROL - Google Patents

Abstract

THE INVENTION CONCERNS AN OVERLOAD SAFETY SYSTEM FOR SLIDER 1 CONTROLLED BY ONE OR MORE RODS 2, 3, EQUIPPED WITH TRANSMISSION PARTS WITH ADJUSTABLE ELASTICITY EFFECT 4.5 PILOTS, IN THE EVENT OF OVERLOAD, BY MEANS OF PARTS QUICK ADJUSTMENT 20,21, IN THE DIRECTION OF AN INTERRUPTION OF THE KINEMATIC TRANSMISSION. AN OVERLOAD SIGNAL IS APPLIED TO AN ENERGY PROVISION STAGE 17 WHOSE OUTPUT IS CONNECTED TO PARTS 20,21 ASSOCIATED WITH EACH CONNECTING ROD, REGULATING PARTS WHICH INTERRUPT, BY MECHANICAL TRANSMISSIONS 22,23, THE KINEMATIC FLOW DELIVERED THROUGH THE TRANSMISSION ORGANS. ELECTRIC IGNITION SYSTEMS OR SYSTEMS PRODUCING A DISCHARGE CURRENT MAY BE USED, THE QUICK ADJUSTMENTS 20,21 BEING EXPLOSION CHAMBERS FOR PYROTECHNIC ELEMENTS OR IONISABLE GASEOUS CHARGES, FLAT COILS OR WIRES.

Description

The invention relates to an overload safety system for presses

  fast linear stroke, in particular for the automatic presses to cut with rod control, whose slider is controlled by one or more rods each bearing on him via a transmission member to

  adjustable elasticity effect, a mechanical converter

  connected to each connecting rod, converter whose output signal is fed, by an electronic amplifier, to a sensor switch sensitive to a

  limit value, a sensor which, when an internal overload

  comes, activates the adjusters associated with the rods and which are connected to the transmission member effect

  corresponding adjustable elasticity.

  Hydraulic overload safety systems are already known for presses operating on rod-jointed arch presses, two-link arch type presses for the manufacture of radiators, arc-cage presses with a connecting rod for

  the compression of metal powders and presses with

  centric. Thus, the patent application filed in the Federal Republic of Germany DE-OS 2,006,297 discloses a method and a device for protecting a press slide controlled by at least two connecting rods.

  several stages of equipment are equipped with a system

  overload safety system. This method provides that the rods are additionally, from the point of view of their load, controlled by electronic measurement systems known per se which, when a given and predetermined indication is reached, put the press at a standstill and, at the same time, time, engage the

  overload safety of the various tooling stages.

  In the device for carrying out the method, the role of load indicator is given to strain gauges associated with the connecting rods and a measuring amplifier. The different loads are added and

  when the desired maximum load is reached, the

  value driver puts the press to a standstill and makes

  at the same time, to transfer the electrically operated safety relief valves

  overload for the various tooling stages.

  The disadvantage of these hydraulic safety systems

  known overload is the importance of the response time.

  Thus, the specialized documentation indicates that when the overload safety systems described above are used on rod-controlled presses with a rate of 35 strokes per minute, the thrust

  still believes, in the event of overload, about 40%

  above its nominal value, between the moment it is

  this nominal value and where the system is

  overload safety system, and the instant of the response. It takes 40 ms to drop the overload until the return at the rated thrust. It must therefore be concluded from this that these known hydraulic overload safety systems, when used on fast presses such as automatic cutting presses (with a nominal speed greater than 200 strokes per minute), expose in the event of overloading. the components and subassemblies of the press, at least during the

  first overload stroke, at unrestricted overload.

  In other words, these overload safety systems are not suitable for fast presses. The causes of these deficiencies lie in the response and switching times of electrical control devices and hydraulic valves with large reversing strokes (motivated by the necessary positive recovery); these times are long compared to the short ones

  time intervals of the overload climb.

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  The subject of the invention is the creation of a system

  of overload safety for fast presses thanks to-

  to prevent the press from being subjected to

  overcharges of an inadmissible value.

  The invention provides an overload safety system for linear stroke fast presses, in particular for rod-controlled automatic cutting presses, the slide of which is controlled by one or more rods each bearing on it via 'a transmission device

  adjustable elasticity effect, a mechanical converter

  electrical connection being associated with each rod, converter whose output signal is fed, by an electronic amplifier, to a sensor switch sensitive to a limit value 1.5 which, when an overload occurs, activates the adjusters associated with the connecting rods and which are connected to the transmission member with corresponding adjustable elastic effect. The response time of this system must be minimized so that as soon as the first overload encountered, it is

limited to an eligible value.

  The provisions of the invention resolve

  This problem arises from the fact that the limit value sensor of each connecting rod is connected by its output, via an OR cell, to an energy supply stage whose output is connected to components rapid adjustment associated with each of the connecting rods, adjusters coupled by a transmission

  mechanical to the transmission element with elastic effect

  corresponding adjustable city, an adjuster

  on the same axis as the adjusters

fast being planned.

  The invention is characterized in that the energy supply stage is an electrical ignition system and the rapid adjustment members are constituted in the form of explosion chambers for pyrotechnic elements or volumes of energy. gas

  electrically activated ionisables, these chambers of

  plosion serving as housing for a piston with axial mobility whose stem comes out of the explosion chamber and

  is connected to said mechanical transmission.

  The invention also provides that the floor of

  provision of energy is a generator of cou-

  discharge discharge known per se and that the rapid adjustment members are made by flat coils enclosed in pressure chambers, a transmission member of the pressure chambers being connected

to the mechanical transmission.

  The invention provides that with the use of a cylinder-piston assembly filled with hydraulic fluid as an elastically adjustable transmission member, a relief valve is mounted in the wall of the cylinder perpendicular to the direction of action of this assembly. cylinder-piston, a relief valve whose control member is removably connected to

the mechanical transmission.

  Keyed controls being used as transmission members with adjustable elastic effect, the invention provides that a positioning key movable perpendicular to the direction in which the key operated is connected is connected.

  removably to the mechanical transmission.

  The invention is also characterized by the fact that the mechanical transmission is carried out by a knee or quadrilateral suspension system.

  occupying, in the deployed position, a perpendicular position

  to the direction in which the adjustable elastically transmitting member acts, the quick adjuster being coupled to the hinge of the toggle system, perpendicular thereto when

  is in the deployed position, the branch of the system to

  a nipple turned on the side of the transmission member bearing on a spring disposed in the longitudinal direction of this system, and in that on the flexing side of the toggle system, the auxiliary adjusting member provided in FIG. axis of the adjustment member

  is shaped as a piston cylinder

  Cost effective in pressure and directed direction of operation

against the quick adjustment member.

  The invention also provides that the explosion chamber is equipped with a capsule-holder for housing an explosive capsule with a controlled igniter

electrically.

  In what follows, the invention is explained

  in more detail using particular embodiments

  given as non-limiting examples. The corresponding figures show: FIG. 1, a schematic representation of the overload safety system according to the invention, FIG. 2, a schematic partial view of the system of FIG. 1, on which are represented a cylinder-piston unit playing the role of energy transmission member and an explosion chamber acting as a rapid adjustment member; - FIG. 3, a schematic partial view of the system of FIG. 1, with a flat coil discharge current generator; 4, a schematic partial view according to FIG. 1, with a keyed control device as energy transmission member, on a rod-type control press according to FIG.

  in FIG. 1, a slide or push rod 1 is sus-

  hanged on a rod control 2; 3 having two driving rods, each of which bears on the slider 1 via a transmission member 4, 5 having elastic properties

  adjustable and a mechano-electric converter 6; 7.

  The outputs of the mechano-electric converters

  6; 7 are respectively connected through

  an amplifier 8; 9 to a sensor-interrup-

  sensitive to a limit value 10; He. In parallel with these arrangements, the outputs of the amplifiers 8; 9 are each connected to a peak value memory 12; 13, itself connected by its output to a

  viewing apparatus 14; 15. The outputs of the

  switches-sensitive to a limit value 10; 11 are connected to an OR cell 16, itself connected by its output to a power supply stage 17. From the energy supply stage

  17, start cable links 18; 19 towards gold

  fast setting ganes 20; 21 associated with each

  transmission shaft 4, 5 with adjustable elasticity. Fast setting members 20; 21, are coupled mechanical transmission members 22; 23 having a

  connection, with the transmission members 4, 5 to

  adjustable voltage, which can be decoupled. On the same axis as the quick-adjusting members 20; 21 and acting in the opposite direction thereof, are arranged adjusting members 24; 25 on the opposite side to the high speed adjusters with respect to

mechanical transmissions 22; 23.

  The schematic and partial representation of the invention shown in FIG. 2 relates to an exemplary embodiment on which a known type piston cylinder assembly 26 enclosing a hydraulic cushion 28 pressurized by a group of pressure generators 27,

  serves as an elastically adjustable transmission

  4, 5 described with reference to FIG. 1. As a rapid adjustment member, there is provided an explosion chamber 29 in which a sensor is housed.

  explosive sule 30 mounted in a capsule-holder, a

  An electrically actuated igniter or detonator 31 and a piston 32 operated by gas expansion, whose rod exits the explosion and expansion chamber 29

  no and connects to the articulation of a knee system

  1st 33 or suspension by quadrilaterals. In the cylinder wall of the cylinder-piston assembly 26 is mounted perpendicularly to the direction of movement of the piston a discharge valve 34 whose control member is

  removably connects to toggle system 33.

  When the toggle system 33 is in the extended position, the discharge valve 34 is held in its closed position by a spring disposed at the other end of the toggle system.

  33 (end opposite to that connected to the valve 34).

  At the electrically operated igniter 31 is connected the cable connection 18 according to FIG. 1, the energy supply stage 17 of FIG. 1 being, according to the embodiment of FIG. , an electric ignition system 36. The auxiliary adjustment member 24 disposed on the side towards which the toggle system 33 is flexed, is shaped as an operator cylinder to

  piston or cylinder-piston assembly and fed

  pressure generating group 27, by means of

from a distributor 37.

  FIG. 3 represents the same construction as FIG. 2, with the exception of the quick-setting member

  and the controlled stage of provision of energy.

  In FIG. 3, this stage (bearing reference 17 in FIG. 1) is embodied as a discharge current generator 38 whose output is connected via the cable connection 18 to a flat coil 40 housed in a pressure chamber 39. An organ. transmission 41 disposed in the pressure chamber

  39 and coming out of it is, in this room

  pressure 39, in operative connection with the coil

  plate 40, its outgoing part being coupled to the articula-

  the toggle system 33.

  FIG. 4 shows an embodiment of the invention using a key drive 42 of known type for producing the transmission member with adjustable elasticity, the toggle system 33 being connected by a detachable connection to a positioning key 43 able to move perpendicular to the direction in

  which exerts the force of the keyed control 42.

  As a quick adjustment member, a pressure chamber 44 filled with a liquid, for example water, is used in which is detachably connected a detonating wire, a pressure chamber serving as a housing for an organ

  transmission 46 connecting to the outside in the article

  The detachable wire is connected to the cable connection 18 from the output of the discharge current generator. The group

  pressure generator 27 and the distributor 37

  2 and used to hold the hydraulic cushion 28 under pressure and to control

  of the auxiliary adjustment member 24 are not

shown in Figures 3 and 4.

  The operation of the overload safety system according to the invention is as follows:

  With the press running, the cinema-

  the following organs of Figure 1:

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  the two connecting rods of the rod control 2; 3, the

  transmission gears 4, 5 with elasticity

  glable, mechano-electric converters 6; 7, the slider or push rod 1, the tool connected thereto on the part, (these two elements are not shown) and the subsets of the b9ti. The effort involved

  during work is transformed into an analogous size

  electrical control by the mechano-electric converters 6; 7, and by the amplifiers 8; 9, transmitted to the sensor-switches 10, 11 sensitive to a limit value and, in parallel, to the peak value memories

  12; 13. The maximum kinematic flow values are

  cken by the peak value memories 12; 13% are

  visualized by the apparatus 14; 15. The sensors

  switches 10, 11 sensitive to a limit value are set on the nominal force and deliver, when this limit value is exceeded, a signal through the OR cell 16, signal for controlling the stage of provision of 17. The electric ignition system 36 (Figure 2) is intended as an upgrade stage.

  energy arrangement is then activated and the voltage of

  The ignition is applied to the igniter 31. The latter then fires the explosive capsule 30.

  being placed in a capsule-holder of the chamber of ex-

  plosion 29, in the direction of the piston 32 operable by the expansion of the gas, this piston is pushed brutally

  against the inner wall of the expansion chamber 29.

  This sudden withdrawal of the piston 32 is transmitted to the toggle system 33 to which it is coupled and the articulation -30 of this system operates. The bending movement of the system causes the opening of the discharge valve 34, the pressure of the hydraulic cushion 28 transmitting the

  overload falls and the overload of the press is abrupt-

  eliminated. After eliminating the cause of the over-

  the burden that has arisen, the security system

  The load is again ready for operation, the dispenser 37 being set to its right-hand switching position, so that the auxiliary regulating member 24 is subjected to the pressure and the discharge valve 34 is closed via the system. knee brace 33. The

  distributor 37 being placed on its switching position

  left, the hydraulic cushion 28 is reconstituted and finally, the explosion chamber 29 being recharged with a new explosive capsule 30 to lighter 31 and its connection to the cable connection 18 made,

  the operating state is restored.

  The operation of the embodiment of FIG. 3 is performed in such a way that the discharge current generator 38 used as an energy delivery stage is kept ready for operation by a suitable charging system. When the nominal force of the press is exceeded, the sensor-switch

  sensitive to the limit value delivers, through

  16, a signal applied to a high current switch belonging to the generator

  38. This signal activates the interrup-

  high current and subjects the flat coil 40 of the pressure chamber 39 to the high discharge current of the generator 38. The control of the flat coil 40 and

  the effort it releases is transmitted through the

  transmission member 41, to the toggle system 33 and cause as has been described for

  Figure 2, the opening of the relief valve 34.

  The pressure of the hydraulic cushion 28 and therefore

  the overload of the press then fall sharply.

  In order for the system to be ready for operation again, the hydraulic cushion 28 is reconstituted, and the intermediate adjustment member 24 operated as described for FIG. 2 and the energy accumulator of FIG.

  discharge generator 38 recharged.

  The operation of the embodiment of FIG. 4 is carried out as in FIG. 3 until the control of the high current switch sensor

  of the discharge current generator 38.

  This new embodiment differs, however, in that the high discharge current is applied to a detonating wire 45 mounted in the pressure chamber filled with a liquid. During the explosion of the wire, the pressure wave produced suddenly pushes the transmission member 46 into the pressure chamber and actuates the toggle system 33. It follows that the positioning key 43 is perpendicularly in the direction of charge of the control 42, a displacement sufficient for the transmission of

  the effort of the connecting rods 2; 3 on the slider 1 is canceled

beyond the bottom dead center.

  To put the system back into

  marrage with this embodiment, it is necessary to mount a new detonating wire 45, to fill the pressure chamber 44 with liquid and to actuate the organ

Auxiliary control 24.

  In all the embodiments of the invention, the signal of the sensor switches 10, 11 sensitive to a limit value is known in the art.

  control in the form of a stop of the machine.

Claims (8)

  1. Overload safety system for linear stroke fast presses, in particular for   biel-controlled automatic cutting presses   the, whose slider is controlled by one or more connecting rods each bearing on him via a transmission member with adjustable elastic effect, a mechanical-electrical converter being associated with each rod, converter whose signal of exit is   brought by an electronic amplifier to a sensor-   a switch sensitive to a limit value which, when an overload occurs, activates the adjusters associated with the connecting rods and which are connected to the correspondingly adjustable elastic output transmission member, characterized in that the limit value sensor (10; 11) associated with each connecting rod is connected by its output, via an OR cell (16), to a power supply stage (17) whose output is connected to components quick-setting means (20; 21) associated with each of the connecting rods, adjusting members coupled by a mechanical transmission (22; 23) to the correspondingly adjustable elastically transmitting member (4; 5), a setting member auxiliary device (24; 25) arranged on the same axis as the   high speed setting (20; 21) being provided.   Overload protection system according to Claim 1, characterized in that the stage of   provision of energy (17) is a system of   electric lighting (36) and that the quick-setting members (20; 21) consist of explosion chambers (29) for electrically activated pyrotechnic elements or ionizable gas volumes, these chambers   apparatus for housing a movable piston (32)   axial unit whose rod leaves the explosion chamber (29) and is connected to the mechanical transmission (22; 23). Overload safety system according to Claim 1, characterized in that the energy supply stage (17) is a discharge current generator (38) and the quick-setting members (20; 21) are formed by flat coils (40) enclosed in pressure chambers (39), a transmission member (41) provided in the pressure chambers (39) being connected to the mechanical transmission (22). Overload safety system according to Claim 1, characterized in that the energy supply stage is a discharge current generator (38) and the quick-setting members   (20; 21) are made by detonating son (45)   in pressure chambers (44), a transmission member (46) provided in the pressure chambers (44)   being connected to the mechanical transmission (22).   5. Overload safety system according to one   Claims 1 to 4 in which cylinder-cylinder assemblies   piston supplied with hydraulic fluid are used as transmission members with adjustable elasticity, characterized in that a discharge valve (34) is arranged in the wall of the cylinder perpendicularly   to the direction in which the cylinder-cylinder   piston, valve whose control device is connected to   releasable way to the mechanical transmission (22).   6. Overload safety system according to one   Claims 1 to 4 in which commands to   key are used as a transmission member with adjustable elasticity, characterized by the fact that   locating key (43) movable   pendicular to the direction in which the   keyed control (42) is connected in a   drivable to the mechanical transmission (23).   7. Overload safety system according to one   Claims 1 to 6, characterized in that   the mechanical transmission (22; 23) is formed by a toggle system (33) occupying, in the deployed position, a position perpendicular to the direction in which the adjustable elastically transmitting transmission element (4; 5) is acting, the quick adjustment member (20; 21) being coupled to the articulation of the toggle system   (33), perpendicular to it when it is in   deployed position, the branch of the toggle system (33) rotated on the side of the transmission member (4; 5) bearing on a spring (35) arranged in the longitudinal direction of this system, and in that on the side bending   of the toggle system (33), the adjuster   The spacer (24; 25) provided in the axis of the quick-setting member (20; 21) is designed as a pressure-operated piston operating cylinder with an operating direction directed against that of the quick-setting member (20; 21). 8. Overload safety system according to one   of claims 1 and 2, characterized in that the   explosion chamber (29) is provided with a capsule holder for receiving an explosive capsule (30) and is   equipped with an electrically operated igniter (31).