WO2025012802A1

WO2025012802A1 - Hydraulic or oleodynamic mold for working metals pieces or objects

Info

Publication number: WO2025012802A1
Application number: PCT/IB2024/056650
Authority: WO
Inventors: Stefano Filippi
Original assignee: Muraro Srl
Current assignee: Muraro Srl
Priority date: 2023-07-10
Filing date: 2024-07-08
Publication date: 2025-01-16
Anticipated expiration: 2026-01-10
Also published as: IT202300014427A1

Abstract

The present invention relates to a hydraulic or oleodynamic press or mold including a first half-mold (2), a second half-mold (3) defining with said first half-mold (2) a molding area or zone (MZ) where metals pieces or objects to be worked in the mold can be arranged.

Description

“HYDRAULIC OR OLEODYNAMIC MOLD FOR WORKING METALS PIECES OR OBJECTS”.

TECHNICAL FIELD OF THE INVENTION

The present invention is a hydraulic or oleodynamic mold for working metal pieces or objects, as well as a molding process using such a mold.

DESCRIPTION OF THE STATE OF THE ART

Hydraulic presses are usually equipped with variable flow pumps, for the movement of respective pressing rams, which pumps are operated by respective electric motors.

The international application published under number W02022190057A1, for example, teaches a hydraulic press with a pressing component, a base component defining with the pressing component a pressing area or zone in which to arrange pieces or objects to be processed.

A motor, one or more pumps for the movement of the pressing component and a flywheel arranged between the motor and the pump are then provided, the flywheel being driven into rotation by the motor and transfers the rotary motion to the pump.

This solution, while satisfactory on the one hand, entails the impossibility of recovering potential energy during the molding phases.

OBJECTS OF THE INVENTION

An object of the present invention is to provide a new hydraulic or oleodynamic press or mold for processing metal pieces or objects.

Another object of the present invention is to provide a new press or mold that allows the recovery of energy that would otherwise be lost.

Another object of the present invention is to provide a new press or mold in which it is possible to perform an energy recovery of potential energy components that would otherwise be dissipated as heat, thereby reducing not only direct energy consumption, but also that related to the disposal of the heat generated.

Another object of the present invention is to provide a new molding method. According to one aspect of the invention, a mold according to claim 1 is provided.

According to another aspect of the invention, a method according to claim 10 is provided.

The dependent claims refer to preferred and advantageous embodiments of the invention.

BRIEF DESCRIPTION OF THE FIGURES

Further advantages, objectives and characteristics as well as embodiments of the present invention are defined in the claims and will be clarified below by means of the following description, in which reference is made to the attached drawing tables; in the drawings, corresponding or equivalent characteristics and/or component parts of the present invention are identified by the same reference numbers.

In particular, in the figures:

- figures 1 and 2 illustrate solutions according to the state of the prior art,

- figures 3 to 6 show embodiments of a press or mold according to the invention.

DESCRIPTION OF FIGURES OF SOLUTIONS NOT ACCORDING TO THE PRESENT INVENTION

With reference first to figure 1, a solution according to the state of the prior art has been illustrated, in which the power supplied by the electric motors 10.2 connected directly to the network or powered by electronic power supplies 10.1 is transferred to the pumps 10.4 (possibly coupled pumps 10.4+10.5), of the 1 quadrant type. A flywheel 10.6 can also be provided between the motor 10.2 and pumps 10.4, 10.5.

The valves of type 20.1 allow the pressing pressure to be controlled, alternatively the latter can be controlled directly through an appropriate control in the pumps 10.4-10.5.

In this case, the direction of movement of the cylinder that pushes the piston 83 of the hydraulic actuator 80 is given by the valves 20.2-20-5 that allow the chambers 81 and 82 of the actuator 80 to be connected alternatively to the mouth P of the pumps 10.4, 10.5 or towards the tank discharge.

A valve 20.11 can also be provided to avoid overpressure in the chamber 81.

The work cycle is typically the following, although other functional schemes are obviously possible.

Initially, the piston 83 falls rapidly due to gravity. In this step, the valves 20.10, 20.9, 20.7 and 20.2 are switched, while the pumps 10.4, 10.5 act on the chamber 82 having switched the valve 20.3. In this step, the piston 83 falls due to gravity and the pre-filling valve 70.2 opens spontaneously (but could also be controlled at the beginning of the fall) sucking oil from the tank 70.3.

Subsequently, the braking step starts, during which the valve 20.7 is closed, the oil is therefore forced to flow through the pressure valve 20.8 (possibly of the proportional type), which generates a back pressure in the chamber 81 which brakes the piston, which slows down reducing the depression that kept the valve 20.7 open which closes spontaneously.

At this point, the working step begins. In this regard, when the valve 20.7 closes, the flow rate of the pumps 10.4, 10.5 alone determines the speed of descent of the piston 83. In this step, the mold or rather the respective pressing component or upper semi-mold integral with the piston 83 in motion, encountering the piece to be worked, produces the force resistant to the deformation of the piece itself which translates into an increase in pressure in the chamber 82. In this manner, since the pressure that can be delivered by the pumps 10.4, 10.5 is greater than the resistant pressure, the flow rate generated by the pumps themselves determines the descent of the piston 83 and therefore of the upper semi-mold to the desired height or force.

Decompression is then started, as once the lower dead center of work has been reached, chamber 82 contains a pressure that must be discharged before the piston 83 and the upper half-mold can be raised.

In this step, the volume of oil contained in chambers 81, 82 of the actuator 80, in the pipes and in the hydraulic blocks has its own elastic energy given by the compressibility of the oil itself which is added to the elastic energy due to the deformation of the structures of the mold or press itself. Normally this energy is discharged in a controlled manner via appropriate ON-OFF or proportional decompression valves 30.4 or via the 20.1.

Once the decompression phase is over, the rapid ascent step begins, in which valve 70.2 is opened and valves 20.10, 20.9, 20.5 and 20.3 are switched, feeding the flow rate of the pumps to chamber 81, which then causes piston 83 to rise, while the flow rate generated by the oil exiting chamber 82 is discharged to the tank via valve 70.2.

An alternative configuration to the one described above is shown in figure 2, in which valves 20.4 and 20.2 are three-way proportional valves, which ensure greater speed of switching of the working direction as well as effective control of the decompression.

In both the previous cases or in any alternative combination of circuit configurations, in the gravity fall and decompression steps, the energies involved (gravitational potential in the first case and elastic potential in the second) are dissipated towards the tank.

EMBODIMENTS OF THE INVENTION

The present invention (see figures 3 to 5) relates to a hydraulic or oleodynamic press or mold 1 including a first half-mold, for example upper 2, a second half-mold, for example lower 3 defining with said first half-mold 2 a molding area or zone MZ where metals pieces or objects to be worked in the mold can be arranged.

The mold 1 further includes at least one hydraulic or oleodynamic linear axis or at least one hydraulic or oleodynamic actuator 4 for operating the upper halfmold 2 to approach/remove to/from the lower half-mold 3. The hydraulic or oleodynamic actuator 4 includes a cylinder 5 with a piston 6 slidably mounted inside it and integral with at least one rod 7, which, in turn, is integral, for example fixed or keyed to it or connected by means of a suitable kinematic mechanism or in another way so that there is motion transfer between them, with the upper half-mold 2. Of course, the piston 6 separates, sealingly, if desired by means of one or more gaskets, the main chamber defined by the cylinder 5 into a first chamber or halfchamber 8a, for example higher than it and a second chamber or half-chamber 8b, for example lower than it.

Alternatively, the actuator 4 could act on the lower half-mold 3, in which case it would alternatively move the lower half-mold 3 towards and away from the upper half-mold 2.

Of course, solutions could also be envisaged in which both half-molds 2, 3 are moved each by one or more respective actuators.

The following description focuses on the embodiment with a mobile upper half-mold 2, but it will be understood that similar considerations also apply to the example with a mobile lower half-mold 3 or with both mobile half-molds 2, 3.

Of course, the actuator is preferably arranged vertically, but it can also be placed horizontally.

The mold 1 also includes at least one drive group 9 designed to feed liquid (for example water, oil, an emulsion, or other liquid) to the hydraulic or oleodynamic actuator 4 to alternatively move the upper half-mould 2 approaching and moving away to/from the lower half-mold 3 and/or the lower half-mold 2 approaching and moving away to/from the upper half-mold 3 for molding objects or pieces (arranged from time to time) in the molding area or zone MZ.

The drive group 9 includes in detail at least one motor 10, in particular electric, designed to drag into rotation a respective main shaft 10a as well as at least one variable displacement pump 11, 12 designed to suck in and discharge a liquid from/into the hydraulic or oleodynamic actuator 9 for moving the upper half-mold 2.

Preferably, an electronic control and power supply system 10b of the motor 10 is provided, this system being a so-called “regenerative” system, i.e. capable of regenerating power towards the mains, possibly powering other users.

Clearly, the electronic control and power supply system 10b is a component of or in any case is controlled by the electronic control unit CPU. The pump 11, 12 has at least two quadrants, i.e. of the reversible type, in particular preferably of the type with electronic control of the displacement.

The pump 11, 12 with two quadrants or of the reversible type, has one port P which is alternatively placed in fluid communication with the half-chambers 8a, 8b and the other S which is placed in fluid communication with a drain or tank or other component 15.

The mold 1 then includes at least one circuit 14 for conveying the liquid in suction, crossing and delivery from/into at least one pump 11, 12, which conveying circuit 14 is designed to suitably convey the liquid pushing or in any case for the movement or displacement of the upper half-mold 2.

It will be understood that the mold or press 1 further includes a group of valves 20.1-20.5, 20.7, 20.8, 20.9, 20.10, which are designed to control and appropriately adjust the supply of the liquid between the pump or pumps 11, 12 and the upper half-mold 2 (and/or the lower half-mould 3) via the conveying circuit 14, being placed to intercept the respective ducts of the circuit 14. The valves can be all or some automatically controlled by the control unit CPU.

The valves could be of any suitable type, for example check or unidirectional, suitably loaded for example elastically loaded or otherwise stressed, slide, ball or other type. The valves could also be of the ON-OFF or proportional or other suitable type. Furthermore, the valves could be unidirectional or two, three or more ways.

A tank 70.3 could also be provided, from which oil or liquid can be taken, via a respective duct 70.4 opening into the actuator 4, if desired into the chamber 8a, for the operation of the mold 1, for example during the fast fall owing to gravity of piston 6 or during another step.

Preferably, the group 9 includes at least one flywheel 13 interposed between the motor 10 and the pump 11, 12, the flywheel 13 being kinematically connected on one side to the main shaft 10a, so that said at least one flywheel is dragged into rotation by the latter or drag it into rotation, and on the other side, to the pump 11, 12 to transfer thereto the rotary motion imparted by said at least one motor or absorb rotary motion from the pump 11, 12 or transfer it to the motor 10. Advantageously, the electronic control and power supply system 10b also acts on the flywheel 13.

The flywheel 13 could have a circular base or even a base of another configuration.

The flywheel 13 preferably has a diameter greater than 600 mm or 800 mm and less than 5 m, preferably with a diameter between approximately 600 mm and 3 m in diameter, for example between approximately 900 mm and 1.5 m, if desired between approximately 1 and 1.2 m or between 1.8 and 2.2 m. Even more preferably, the flywheel 13 has a thickness between about 200 and 1000 mm, for example between about 300 and 500 mm, preferably about 380-400 or 390 mm.

If the flywheel 13 does not have a circular base, it could still have a cross section or in any case an extension in a plane orthogonal to that of rotation equal to approximately 0.5-4 m², if desired approximately 0.8-1, 2 m² or 0.9-1 m².

Advantageously, the flywheel 13 is made of metal, such as steel, but the same could also be made of other materials, for example even a composite material.

The structure of the mold or press, with particular reference to the support and connection structure of the motor, flywheel and pump, could be for example as described in the international application published under number W02022190057A1.

Thus for example, the mold or press 1 could include at least one electronic or electro-mechanical switching component for switching between different operating conditions of the pump 11, 12.

The switching component is responsible for varying the displacement of the pump and also, if desired, inverting the direction of thrust of the fluid in the pump, thus from the pump 11, 12 (or rather from a tank 15 in fluid communication with the pump) towards the actuator 4 or vice versa.

With particular reference to the presence of the flywheel 13, thanks to the switching component it is possible to switch the pump 11, 12 between different operating conditions, in particular at least one first and at least one second operating condition. In the first operating condition, the pump 11, 12 is kinematically connected to the flywheel 13 and receives motion from it, while in the second condition it imparts motion to it. Clearly, if the pump 11, 12 receives motion from the flywheel 13, the rotation of the flywheel 13 determines a corresponding rotation of a second shaft or rotation component of the pump 11, 12 and a defined flow rate of liquid in the conveying circuit 14 up to reach or so as to activate the upper half-mold 2 and displace or move it appropriately.

In the second operating condition instead the pump 11, 12 does not receive motion from it, but it imparts motion to the flywheel 13. In this step, the pump can transfer rotary motion to the flywheel or accelerate or maintain the rotation speed of the flywheel 13 for subsequent treatment steps or impart rotation to the motor 10, which (through intervention of the electronic control and power supply system 10b) then acts as an energy generator. This condition occurs when, by appropriately inverting the displacement of the pumps 11-12, a defined flow rate of liquid at a given pressure is made to flow from the circuit via pipes 15, 16 of the circuit 14 up to the ports P of the pumps and from the ports P to the ports S, thereby generating a torque which is transmitted through a suitable connection shaft to the flywheel 13.

Therefore, in the second operating condition, the force or energy or power deriving from this flow rate of pressurized liquid is transmitted to the flywheel 13 and if desired to the motor 10 and is not wasted.

Thanks to this, in the second operating condition, the pumps 11, 12 can transmit a net torque to the flywheel-motor assembly 13, 10 which can be used advantageously to appropriately increase the revolutions of the flywheel 13 and to effectively “load” it, i.e. to provide this component with energy or power to be returned at least in part during the first operating condition.

In essence, when the upper 2 (and/or lower 3) half-mold has been displaced as desired, if desired when pressing of a workpiece is finished, the energy used by the flywheel 13 to operate the pump 11, 12 and appropriately pushing the liquid into the circuit 14 up to or so as to activate the upper 2 (and/or lower 3) half-mold determines a reduction in the flywheel revolutions, for example from approximately 1500 revolutions to approximately 1300 revolutions.

Therefore, as will be understood, the flywheel 13 instead receives and actually stores in successive steps, the power or rotation energy from the motor 10 during the second operating condition and preferably during both the first and second operating conditions, until, of course, motor 10 is switched on.

To better explain this concept, the flywheel 13 is fixed or keyed onto the main shaft 10a or onto an auxiliary shaft rigidly coupled or integral with it or the flywheel 13 is in one piece with the main shaft 10a or with the possible auxiliary shaft, whereby by operating the motor 10 the latter causes the flywheel 13 to rotate, but not necessarily with the same rotation revolutions, that is to say that the auxiliary shaft and shaft 10a of the motor 10 rotate preferably with same number of turns.

As will be said later, the pump 11, 12 can also transfer rotational energy to the flywheel 13 during specific treatment steps.

The mold also includes an electronic control unit CPU designed to control components of the mold so as to determine or carry out, by appropriately positioning or switching in particular the pump 11, 12 and the valves, at least one step in which the liquid coming out from a chamber 8a, 8b of the cylinder 5, preferably the chamber 8b lower than the piston 6, is conveyed towards or sucked by the pump 11, 12 and thus the latter, depending on the energy received from this flow of liquid, accelerates or maintains the speed of rotation of the flywheel 13 or in any case transfers rotary motion to it or in any case so that, depending on the energy received from this flow of liquid, it is possible to carry out an energy recovery of potential energy components otherwise dissipated in heat. In essence, if a flywheel is not provided, during the steps in which the pump 11, 12 acts as a “motor”, it could, for example, be selected whether to modulate the torque/speed control of the motor 10 in order to recover the torque to the mains.

Advantageously, the electronic control unit CPU is responsible for controlling the components (valves, pumps, motor, possibly electronic control and power supply system of the or of a motor and/or switching component and/or other) of the mold so as to perform the following steps in sequence to the hydraulic or oleodynamic actuator 4 and then to the upper 2 and/or lower 3 half-mold:

- fast approach step, if desired, a fast fall by gravity (in the event that the upper half-mold 2 is moved), during which the piston 6 is moved towards the molding area or zone MZ or falls or moves towards the bottom, if desired by gravity, with any suitable speed, for example, but not limited to between 150 and 500mm/s,

- braking step, during which the flow of fluid exiting the chamber 8b and entering the ports P of the pump 11,12, is appropriately controlled and consequently a back pressure is generated in the chamber 8b of the cylinder 5 lower than the piston 6, which back pressure brakes the piston 6, slowing down its descent according to the law of control of the flow rate at the ports P or movement towards the molding area or zone MZ,

- working step or rather molding or pressing step, during which the pump 11, 12 controls, by means of liquid fed through the circuit 14, the speed of movement or descent of the piston 6, feeding liquid to the chamber 8a of the cylinder 5 above the piston 6; in this step the upper half-mold 2 and/or the lower half-mold 3, coming into contact with the piece or object to be machined, produces the force resistant to the deformation of the object or piece itself which translates into an increase in pressure in the chamber distal from the molding zone MZ, for example the chamber 8a of the cylinder 5 above the piston 6,

- decompression, in which, once the molding or pressing has been completed, once the lower working dead center has been reached, the chamber 8a of the cylinder 5 above the piston 6 contains a pressure which must be released before moving the piston 6 backwards or ascent into the cylinder 5,

- rapid removal or return to position or rapid ascent, in which the piston 6 is moved away from the pressing zone MZ, for example it is made to go up, with any suitable speed, for example, but not limited to between 150 and 500mm/s.

In this case, the electronic control unit CPU is responsible for controlling the components (valves, pumps, motor, possibly electronic control and power supply system of a or of the motor and/or switching component and/or other) of the mold, so that the liquid leaving the chamber 8b of the cylinder 5 lower than the piston 6 is conveyed towards or sucked by the pump 11, 12 at least during the gravity fall step and/or during the decompression step and/or during the rapid removal or return to position or rapid ascent step and thus the latter 11, 12, depending on the energy received from this flow of liquid, accelerates or maintains the rotation speed of the flywheel 13 or in any case transfers rotary motion to it.

Preferably, the electronic control unit is responsible for controlling the components (valves, pumps, motor, possibly electronic control and power supply system of the motor and/or switching component and/or other) of the mold 1, so that, in case of vertical actuator 4 and upper half-mold 2 mobile and responsible for pressing, during the gravity fall step, the falling speed of the piston 6 is controlled by controlling the flow rate of liquid exiting the chamber 8b of the lower cylinder piston 6 towards at least one pump 11, 12 or towards the port P of the latter, modulating the displacement of the latter, so that the pump 11, 12 can transfer rotary motion to the flywheel 13 depending on the energy conveyed by the liquid coming out of the cylinder 5, preferably from the chamber 8b.

If a flywheel is not provided, during the steps in which the pump 11, 12 acts as a “motor” it could, for example, be selected whether to modulate the torque/ speed control of the motor 10 so as to recover the torque to the mains.

Clearly, in presence of relevant flywheel inertia, for example of the type of flywheel 13, it is possible to use the pair of pumps 11, 12 to reaccelerate more quickly the flywheel 13 is obviously more interesting in practice and offers a better energy balance as recovering energy to the mains also has efficiency.

Of course, a variable displacement pump could be structured in any suitable manner, for example, but not limited to, as described in the international application published under W02022190057A1.

Even more preferably, the electronic control unit is responsible for controlling the components (valves, pumps, motor, possibly electronic control and power supply system of the motor and/or switching component and/or other) of the mold, so that, again in the case of a vertical actuator 4 and upper half-mold 2 mobile and responsible for pressing, during the gravity fall step of the piston 6, the latter, controlling the flow rate of liquid exiting the chamber 8b of the cylinder lower than the piston 6 towards the pump 11, 12, by modulating the displacement of the pump 11, 12, is braked near the contact point of the upper half-mold 2 with a piece being processed.

In essence, during this step, the valves are opened/closed appropriately, so that the flow rate of liquid exiting the chamber 8b is conveyed towards the pump 11, 12 and the displacement of the pump 11, 12 is controlled or modulated, such that the flow rate of liquid exiting chamber 8b is controlled.

If desired, during the gravity fall step, valves 20.10, 20.9, 20.7 and 20.5 are switched open.

However, in the case of a vertical actuator 4, but with the lower half-mold 3 mobile and responsible for pressing (also if desired in combination with an upper half-mold 2 mobile), then what has been indicated for the gravity fall step would apply to the step of removal or rapid return to position or rapid ascent.

Clearly, suitable sensors or means for detecting the operating conditions and positions of the various components of the press or mold can also be provided.

Advantageously, in addition or alternative to what is now indicated, whether the actuator is vertical (with upper 2 and/or lower 3 half-mold moving towards/away from the other for pressing), or in the case in which it is horizontal, the electronic control unit CPU is responsible for controlling components (valve, pump, motor and/or other) of the mold, so that at the end of the working step, during the decompression step, when the flywheel 13 has slowed down its speed of rotation by transferring kinetic energy towards the pump 11, 12, the direction of the flow rate delivered by the pump 11, 12 is reversed which will then discharge the compressed liquid inside a chamber of the cylinder 5 or preferably of the respective chamber 8b lower than the piston 6, recovering the elastic energy contained in the volume of pressurized liquid as well as in the frame of the mold or press. Therefore, the pump 11, 12 transfers, also in this case, rotary motion to the flywheel 13 as a function of the energy conveyed by the liquid exiting a chamber of the cylinder 5, preferably from the chamber 8b.

In essence, at the end of the working step, when the flywheel(s) 13 will have slowed down its/their rotation speed by transferring kinetic energy towards the pump(s) 11, 12, it will be possible to reverse the direction of the flow rate delivered from the pump 11, 12 itself, which will then discharge the compressed liquid or oil inside the cylinder 5 or preferably inside the respective half-chamber 8b, recovering the elastic energy contained in the volume of pressurized liquid or oil as well as in the frame of the mold or press. The torque generated by the pumps 11, 12 will accelerate the flywheel(s) 13, thus reducing the torque requirement supplied by the motors 10 to bring the speed of the flywheels 13 back to initial speed.

It is reiterated that the flywheel 13 could be not foreseen, so that during the steps in which the pump 11, 12 acts as an “motor” it could, for example, be selected whether to modulate the torque/ speed control of the motor 10 in order to recover in mains the torque via the electronic control and power system 10b.

If desired, the motor 10 includes at least one servomotor powered by the electronic control unit CPU. In this case, clearly, the pump 11, 12 is driven by the servomotor.

The at least one pump preferably includes two pumps 11, 12, not in communication with each other or in communication with each other and driven by the same shaft, so by activating one pump 11 the other pump 12 is automatically activated or not.

If the pumps 11, 12 are in communication, one or both pumps 11, 12 would be hollow or in any case would define a passage opening of a respective shaft. Alternatively, other components can be provided for driving both pumps 11, 12 by means of the same second shaft or a same component driven in rotation by the main shaft 10a or better yet by the auxiliary shaft.

It will be understood that larger single pumps are rarer on the market and thus more expensive than a double pump with the same total displacement. Furthermore, two smaller pumps can allow the displacement to be modulated more quickly than a single big pump.

Alternatively, it is possible to mount two or more pumps of different types on the same shaft, for example one with two quadrants and one with four quadrants, increasing flexibility in the development of possible operating schemes.

Clearly, a mold or press 1 according to the present invention can have multiple groups or structures as described above, all of which are designed to control one or more respective actuators 4 for the movement of the same or different upper half-molds 2.

In this case, these groups could all be supported by the same base.

Furthermore, in this case, a single liquid conveying circuit 14 could be provided for all the groups, with one or more collector pipes 16 or more conveying circuits 14 for each drive group or even an intermediate solution between these.

Subject-matter of the present invention is also a molding or pressing method using a mold according to the present invention, in which the electronic control unit appropriately controls or commands components of the mold to obtain the desired control steps or rather for the conveyance of the liquid from the cylinder 5, if desired from the respective chamber 8b towards the pump 11, 12.

A construction variant of the diagram in figure 3 is represented in figure 5, in which the pump 12a is a four-quadrant pump with electronic displacement control. Actually, the principle of figure 3 is also applicable to mixed pump systems composed entirely or partially of electronically controlled 2 or 4 quadrant pumps.

With reference to this aspect, a 4-quadrant pump, both with fixed and variable displacement, is able to function both as a pump and as a hydraulic motor, processing flow rate to and from each of its ports (A, B).

Alternative schemes are clearly possible, in which there are also proportional valves 17 of the 2 or with more ways of the type 30.4 of the scheme in figure 1 (see figures 4 and 5) or 3 way valves of the type 20.4 and 20.2 in figure 2 designed to speed up the change of direction or decompression steps. In this case the energy advantages are reduced as part of the energy is dissipated. In all cases it is possible that the circuit includes an intermediate pressure intensifier or multiplier into which the conveying circuit 14 opens and which is then in fluid communication, via a specific auxiliary liquid conveying circuit with the actuator 4.

According to this variant, the at least one pump 11, 12, 12a, instead of sending liquid directly into the cylinder or cylinders 5, sends it into a pressure multiplier which serves to increase the pressure of the liquid to the detriment of the flow rate.

This multiplier could, as is known, have a small cylinder-piston group and a large cylinder-piston group, in which case, the oil or water conveyed by the pump or pumps 11, 12, 12a would act directly on the big cylinder-piston group and this would cause a displacement of the small cylinder-piston group with displacement of a respective fluid or liquid, thereby effectively multiplying the pressure to the detriment of the flow rate.

As will be understood, compared to previous solutions, thanks to the present invention, except for the efficiency, the gravitational potential energy can be stored as kinetic energy in the flywheel or flywheels 13. In fact, the pressure and flow rate determined by the flow of liquid or oil exiting from the chamber 8b towards the pumps 11, 12 effectively transforms the latter into torque generators which can be used by appropriately modulating the current control of the system 10b towards the motor 10 (i.e. by putting the electric motor in “neutral”) to increase the rotation speed of the flywheel(s) 13, making this energy available again to the pumps 11, 12 in the subsequent work step.

Therefore, this configuration allows an energy recovery of one or preferably two components of potential energy otherwise dissipated as heat, thus reducing not only direct energy consumption, but also that linked to the disposal of the heat generated.

Furthermore, the braking and decompression steps can be controlled in a more precise and effective manner compared to solutions according to the prior art.

Finally, with reference to figure 6, a variant of the present invention has been illustrated, similar to the example in figure 4, but in which there are several drive groups 9a, 9b, with motor, pump and, if desired, flywheel.

In the previously indicated operating cases, the groups operate individually as described.

However, by having several drive groups 9a, 9b, further interaction between them is possible. In particular, according to the examples previously recalled, as described so far, the power systems 10b were of the so-called "regenerative" type, i.e. having the possibility of regenerating power towards the mains, possibly powering other users.

In accordance instead with the example in figure 6, it could be possible to have several groups of the type 9a equipped with regenerative power supply units 10b and other groups 9b equipped with non-regenerative power units 10b.1. In this case, during the braking phase of the flywheels, in one or more non-regenerative groups 9b, for example at the end of the shift or in the event of a lack of energy from the mains, or in any case in the absence of power from the power supply 10b.1 towards the flywheel 13b, it is possible through the pumps 11b and 12b, suitably controlled by the electronic control unit CPU or by a respective component, to transfer flow rate into the circuit 14, for example into a collector pipe 16 and through this to power the pumps 11, 12 of one or more regenerative units 9a, which will transfer torque to the respective flywheel (or flywheels) 13 which in this case could be braked in a controlled manner via the motor 10 and the regenerative power supply 10b.

Since the regenerative power supplies 10b are definitively more complex and expensive than the non-regenerative power supplies 10b.1, and given that in the work steps, the potential energies can only be recovered by accelerating the flywheels 13, 13b, it is thus convenient to have a configuration that is more simple and economical for power systems.

Therefore, it is understood that the present invention is capable of achieving the intended objects.

Claims

1. Hydraulic or oleodynamic press or mold including a first half-mold (2), a second half-mold (3) defining with said first half-mold (2) a molding area or zone (MZ) where metals pieces or objects to be worked in the mold can be arranged, said mold further comprising at least one hydraulic or oleodynamic actuator (4) for operating said first half-mold (2) and/or said second half-mold (3), said at least one hydraulic or oleodynamic actuator (4) comprising a cylinder (5) with a piston (6) slidably mounted inside it and integral with at least one rod (7), in turn, integral with said first half-mold (2) and/or with said second half-mold (3), said piston (6) separating the main chamber defined by said cylinder (5) into a first chamber or chamber (8a) above said piston (6) and a second chamber or chamber (8b) below said piston (6), said press or mold even comprising at least one drive group (9) designed to feed liquid to said at least one hydraulic or oleodynamic actuator (4) to move said first half-mold (2) approaching and moving away to/from said second half-mold (3) and/or said second half-mold (3) approaching and moving away to/from said first half-mold (2) for molding objects or pieces in the molding area or zone (MZ), said drive group (9) including:

- at least one motor (10) designed to drag into rotation a respective main shaft (10a),

- at least one variable displacement pump (11, 12) designed to suck and discharge a liquid from/into said at least one hydraulic or oleodynamic actuator (9) for moving said first (2) and/or second (3) half-mold,

- at least one circuit for conveying (14) said liquid in suction, crossing and delivery from/into said at least one pump (11, 12), which conveying circuit (14) is designed to suitably convey the liquid pushing or in any case for the movement or displacement of said first (2) and/or second (3) half-mold, wherein said at least one pump (11, 12) is at least a two-quadrant pump, and wherein said mold even comprises an electronic control unit (CPU) for controlling components of said mold so as to determine or carry out at least one step in which the liquid coming out from said cylinder (5) is conveyed towards or sucked from said at least one pump (11, 12), so that, depending on the energy received by said at least one pump (11, 12) through this flow of liquid, it is possible to carry out an energy recovery of components of potential energy otherwise dissipated.

2. Press or mold according to claim 1, wherein said electronic control unit (CPU) is designed to control components of said mold so as to cause said at least one hydraulic or oleodynamic actuator (9) and then the first (2) and/or second (3) half-mold to carry out the following steps in sequence:

- fast approach step, during which said piston (6) is moved towards the molding area or zone (MZ),

- braking step, during which a back pressure is generated in the cylinder chamber proximal to the molding zone (MZ) or compressed during the fast approach step, which back pressure brakes said piston (6), slowing down its movement towards the molding zone (MZ),

- working or better molding or pressing step, during which said at least one pump (11, 12) controls, by means of liquid fed through said circuit (14), the movement speed of the piston (6) feeding liquid to a chamber of the cylinder (5) far or distal from the molding zone (MZ), in this step the first half-mold (2) and/or the second half-mold (3) coming into contact with the piece or object to be machined, produces/produce the force resistant to deformation of the object or piece itself which translates into an increase in pressure in the cylinder chamber (5) far or distal from the molding zone (MZ),

- decompression step, in which, once the molding or pressing is complete, having reached the bottom dead center of work, the cylinder chamber (5) far or distal from the molding zone (MZ) contains a pressure that must be released before performing the movement backwards of the piston (6) in the cylinder (5),

- rapid removal or return to position step, in which the piston (6) is moved away from the molding zone (MZ), said electronic control unit (CPU) being designed to control components of said mold so that the liquid leaving said chamber (8b) of the cylinder (5) proximal to the molding zone (MZ) is conveyed towards said at least one pump (11, 12) at least during said fast approach step and/or during said decompression step and/or during said rapid removal or return to position step, so that, depending on the energy received from said at least one pump (11, 12) by such a flow of liquid, it is possible to carry out an energy recovery of potential energy components otherwise dissipated.

3. Press or mold according to claim 2, wherein said at least one actuator (4) is arranged with vertical trim and said first half-mold (2) is movable and responsible for pressing, and wherein

- said fast approach step comprises a step of fast fall by gravity, during which the piston (6) of said at least one hydraulic or oleodynamic actuator (4) falls by gravity,

- during said braking step, a backpressure is generated in the chamber (8b) of said cylinder (5) below said piston (6), which backpressure brakes the piston (6), slowing down its descent,

- said removal step or rapid return to position step is a step of rapid ascent, in which the piston (6) is made to go up again, said electronic control unit (CPU) being designed to control components of said mold so that the liquid leaving said chamber (8b) of the cylinder (5) below the piston (6) is conveyed towards said at least one pump (11, 12) at least during said gravity fall step and/or during said decompression step, so that, depending on the energy received by said at least one pump (11, 12) through this liquid flow, it is possible to carry out an energy recovery of components of potential energy otherwise dissipated.

4. Press or mold according to claim 2 or 3, wherein said electronic control unit is designed to control components of said press or mold, so that during the step of fall by gravity the speed of fall of said piston (6) is controlled by controlling the flow rate of liquid leaving the chamber (8b) of the cylinder proximal to the pressing zone (MZ) towards said at least one pump (11, 12), modulating the displacement of the latter.

5. Press or mold according to claim 4, wherein said electronic control unit (CPU) is designed to control components of said mold, so that during the fast approach step, by controlling, through modulating the displacement of the pump (11, 12), the flow rate of liquid leaving the chamber (8b) of the cylinder proximal to the pressing zone (MZ) towards said at least one pump (11, 12), said piston (6) is braked near the contact point of the first half-mold ( 2) with a piece being worked.

6. Press or mold according to claim 2 or 3 or 4 or 5, wherein said electronic control unit (CPU) is designed to control components of said mold, so that at the end of the working step, during the decompression step, the flow direction delivered by the pump (11, 12) itself is inverted, which pump will then discharge the compressed liquid inside the cylinder (5) recovering the elastic energy contained in the volume of pressurized liquid as well as in the mold frame.

7. Press or mold according to any of the preceding claims, comprising at least one flywheel (13) interposed between said at least one motor (10) and said at least one pump (11, 12), said at least one flywheel (13) being kinematically connected on one side, to said at least one main shaft (10a), so that said at least one flywheel (13) is driven into rotation by the latter or drags it into rotation, and from the other side, to said at least one pump (11, 12) for transferring to it the rotary motion imparted by said at least one motor (10) or absorbing rotary motion from the pump (11, 12) or transferring it to the motor (10), and wherein said electronic control unit (CPU) is responsible for controlling components of said mold so as to determine or carry out at least one step in which the liquid leaving said cylinder (5) is conveyed towards or sucked in by said at least one pump (11 , 12) and therefore the latter, depending on the energy received from this flow of liquid, accelerates or maintains the rotation speed of said at least one flywheel (13) or in any case transfers a rotary motion to it.

8. Press or mold according to any one of the preceding claims, wherein said at least one pump (11, 12) has at least four quadrants with displacement electronic control.

9. Press or mold according to any one of the preceding claims, wherein said at least one motor (10) comprises at least one servomotor powered by said electronic control unit (CPU), said at least one pump (11, 12) being driven by said servomotor.

10. Press or mold according to any one of the preceding claims, wherein said at least one pump (11, 12) comprises two pumps in or out of communication with each other.

11. Press or mold according to any one of the preceding claims, comprising at least two drive groups (9a, 9b), one of which (9a) is provided with an electronic control and power supply system (10a) of the respective regenerative motor (10) or capable of regenerating power towards the mains, possibly feeding other users, while at least one other (9b) of said drive groups is provided with an electronic control and power supply system (10b) of the respective non-regenerative motor (10).

12. Press or mold according to claim 11, wherein said electronic control unit (CPU) is set during specific steps to control said at least one pump (1 lb, 12b) of a drive group (9b) with non-regenerative electronic control and power supply system (10b) to transfer flow rate in the circuit (14) and through this to feed said at least one pump (11, 12) of an drive group (9a) with regenerative electronic control and power supply system (10b).

13. Molding method using a mold according to any one of the preceding claims, wherein said electronic control unit (CPU) controls components of said mold so as to determine or carry out at least one step in which the liquid leaving said cylinder (5) is conveyed towards or sucked by said at least one pump (11, 12) so that, depending on the energy received by said at least one pump (11, 12) through this flow of liquid, it is possible to carry out an energy recovery of components of potential energy otherwise dissipated.

14. Method according to claim 13 by means of a press or mold according to claim 2, wherein said electronic control unit (CPU) controls components of said press or mold so that the liquid leaving a chamber (8b) of the cylinder (5) is conveyed towards said at least one pump (11, 12) at least during said fast approach step and/or during said decompression step and/or during said rapid removal or return to position step, so that, depending on the energy received from said at least a pump (11, 12) by means of this flow of liquid, it is possible to carry out an energy recovery of components of potential energy otherwise dissipated.

15. Method according to claim 13 or 14 by means of a press or mold according to claim 3, wherein said electronic control unit (CPU) controls components of said mold so that the liquid leaving said chamber (8b) of the cylinder (5) below the piston (6) is conveyed towards said at least one pump (11, 12) at least during said step of fall by gravity and/or during said decompression step, so that, depending on the energy received from said at least one pump (11 , 12) by means of this flow of liquid, it is possible to carry out an energy recovery of components of potential energy otherwise dissipated.

16. Method according to claim 15, wherein said electronic control unit controls components of said press or mold, so that during the step of fall by gravity the speed of fall of said piston (6) is controlled by controlling the liquid flow rate leaving the chamber (8b) of the cylinder below the piston (6) towards said at least one pump (11, 12), modulating the displacement of the latter.

17. Method according to claim 16, wherein said electronic control unit (CPU) controls components of said press or mold, so that during the step of fall by gravity, by controlling, owing to modulation of the displacement of the pump (11, 12), the flow rate of liquid leaving the chamber (8b) of the cylinder below the piston (6) towards said at least one pump (11, 12), said piston (6) is braked near the contact point of the first half-mold (2) with a piece being worked.

18. Method according to claim 15 or 16 or 17, wherein said electronic control unit (CPU) controls components of said press or mold, so that at the end of the working step, during the decompression step, when said at least one flywheel (13) has slowed down its rotation speed by transferring kinetic energy towards said at least one pump (11, 12), the direction of the flow rate delivered by the pump (11, 12) itself is reversed and the pump will then discharge the liquid compressed inside the cylinder (5) by recovering the elastic energy contained in the volume of pressurized liquid as well as in the mold frame.

19. Method according to any one of claims from 13 to 18 by means of a mold according to claim 6, wherein said step according to which, depending on the energy received by said at least one pump (11, 12) through this flow of liquid, it is possible to carry out an energy recovery of otherwise dissipated potential energy components comprises or consists of a step in which said at least one pump (11, 12), depending on the energy received from said liquid flow, accelerates or maintains the rotation speed of said at least one flywheel (13) or in any case transfers a rotary motion to it.