STAMPING PRESS EQUIPPED WITH A CONVEYOR SYSTEM DRIVEN BY RECYCLED FLUID

Abstract

STAMPING PRESS EQUIPPED WITH A CONVEYOR SYSTEM DRIVEN BY A RECYCLED FLUID The present invention relates to a stamping press (2) for sheet metal (10) comprising: - an upper frame (12), movable vertically relative to a fixed chassis (4), and to a lower frame (6); - a system (8) for damping the movement of the upper frame, comprising balancing cylinders (14) connected to said upper frame and fluidically connected to a fluid reservoir (16) to balance the pressure within said balancing cylinders; noteworthy in that said stamping press further comprises: - a conveyor system (18) comprising a conveyor belt (20) for the stamped sheet metal, and a transmission shaft provided with a turbine (22) configured to rotate said transmission shaft, by the action of a compressed fluid coming from the fluid reservoir, so as to set the conveyor belt. (Figure to be published with the abstract: Figure 1)

Description

Title of the invention: STAMPING PRESS EQUIPPED WITH A CONVEYOR SYSTEM DRIVEN BY A RECYCLED FLUID Technical field

[0001] The invention relates to the field of stamping, and more particularly to the field of sheet metal stamping presses for motor vehicles. Prior art

[0002] In the automotive metal parts manufacturing industry, it is common to use progressive stamping press lines to shape parts in several stages, where each press performs a specific operation on the same part, which is transferred from one press to another using inter-press robots. In this process, conveyor belts play an important role in transporting and evacuating the finished parts, for example, to stacking areas.

[0003] Existing conveyor belt power solutions often rely on independent electric motors, hydraulic systems or external power sources. This leads to increased electricity consumption and increased dependence on external resources, with limitations in terms of availability and capacity. These factors can affect the overall energy efficiency of the stamping process and have a negative impact on the environment, especially if they use fossil fuels or non-renewable electricity.

[0004] The published patent document EP 1 882 534 A1 discloses a press equipped with a die damping system which comprises a damping pad and hydraulic cylinders controlled by electric motors, said press being capable of converting, through the electric motors, the hydraulic energy produced during the damping of the die into electrical energy necessary for the die damping action.

[0005] However, the solution disclosed by the document makes it possible to optimize the control energy of the hydraulic cylinders, but does not make it possible, for example, to power the movement of a conveyor belt of a stamped sheet metal conveyor. Statement of the invention

[0006] The present invention aims to overcome at least one of the drawbacks of the aforementioned state of the art. More particularly, the invention aims to propose a simple, efficient and economical solution for optimizing the energy efficiency of stamping presses.

[0007] To this end, the invention relates to a sheet metal stamping press comprising: - a main, stationary chassis; - a lower frame, fixed with the chassis; - an upper frame, movable vertically relative to the chassis and the lower frame; - a system for damping movement of the upper frame, comprising balancing cylinders connected to said upper frame and fluidically connected to a fluid reservoir to balance the pressure within said balancing cylinders; remarkable in that said stamping press further comprises: - a conveyor system comprising a conveyor belt for the stamped sheet metal, and means for rotating said conveyor belt comprising a transmission shaft provided with a turbine configured to rotate said transmission shaft, by the action of a compressed fluid coming from the fluid reservoir, so as to set the conveyor belt in motion.

[0008] Advantageously, the conveyor system is arranged on a floor of the stamping press, or fixed to the frame of said press.

[0009] According to one embodiment, the means for rotating the conveyor belt further comprise an electric motor, and the transmission shaft comprises an electric generator rotor capable of converting the rotation of the turbine into electrical energy, so as to power said electric motor.

[0010] According to one embodiment, the fluid reservoir, the balancing cylinders and the turbine form a closed circuit for recycling the compressed fluid, where said compressed fluid is configured to circulate in a closed loop following each stamping cycle of said stamping press.

[0011] According to one embodiment, the closed circuit for recycling the compressed fluid comprises a fluid outlet conduit extending from the reservoir to the turbine, and a fluid outlet conduit extending from said turbine to said fluid reservoir.

[0012] According to one embodiment, each of the fluid outlet and outlet conduits is provided with an electrically controlled one-way valve.

[0013] According to one embodiment, the stamping press further comprises a control and command unit configured to control the one-way valve, as a function of a pressure threshold of the fluid in the fluid reservoir.

[0014] According to one embodiment, the compressed fluid corresponds to compressed air.

[0015] The invention also relates to a method of stamping sheet metal carried out by a stamping press according to the invention, and comprising the following steps: - vertical descent from the upper frame to the lower frame to stamp the sheet metal; - compression of the fluid from the balancing cylinders to maintain a balanced load and essentially constant pressure on the sheet; - circulation of the compressed fluid from the corresponding balancing cylinder to the fluid reservoir; - circulation of compressed fluid from the fluid reservoir to the turbine; - generation of a rotational movement of the transmission shaft, causing the conveyor belt of the conveyor system to move.

[0016] According to one embodiment, the step of circulating the compressed fluid from the fluid reservoir to the turbine is conditioned by a measurement of the pressure of the fluid in said fluid reservoir, followed by an activation of the circulation of the compressed fluid by means of an electrically controlled one-way valve, when the measured pressure is greater than or equal to a predetermined threshold.

[0017] According to one embodiment, said method further comprises a step of vertically raising the upper frame, followed by a return of the fluid to the fluid reservoir, just after said fluid has passed through the turbine.

[0018] The measures of the invention are advantageous in that the closed circuit for recycling the compressed fluid formed by the fluid reservoir, the balancing cylinders and the turbine, makes it possible to optimize the energy efficiency and operational effectiveness of the stamping press.

[0019] Indeed, setting the conveyor belt in motion by the action of the compressed fluid coming from the fluid reservoir makes it possible to reduce the dependence of the conveyor system on external energy sources. Brief description of the drawings

[0020] [Fig. 1] represents a perspective view of a sheet metal stamping press according to the invention, comprising a conveyor system fed from the movement damping system of the upper frame;

[0021] [Fig.2] represents a schematic view of the stamping press of [Fig.l]. Detailed description

[0022] [Fig.l] represents a perspective view of a sheet metal stamping press 2 10 according to the invention.

[0023] The press 2 comprises a fixed main frame 4 with a lower frame 6 on which the sheet metal 10 to be stamped is deposited, and also comprises an upper frame 12 movable vertically (along the Z axis) relative to the frame 4 and to the lower frame 6. Reference is generally made to a closing or an opening of the stamping press 2 when the upper frame 12 is, respectively, in a low or high position relative to the lower frame 6.

[0024] The press 2 is also provided with a damping system 8 for the movement of the upper frame 12, comprising balancing cylinders 14, generally designated by: balancers 14, connected to said upper frame 12 and fluidically connected to a fluid reservoir 16 to balance the pressure within said balancers 14, in order to maintain a constant pressure in the latter and thus maintain the stability of the press 2, even in the presence of an uneven load during the stamping operation.

[0025] Indeed, during the stamping operation, when the press closes, the fluid inside the balancer 14 is compressed, which causes an increase in pressure. To avoid imbalances in the press due to overpressure, the pressurized fluid is directly conveyed to the reservoir 16 to accumulate and help maintain a substantially constant pressure inside each balancer 14. Preferably, the fluid reservoir 16 comprises a total fluid accumulation capacity of between 5 dm3 and 50 dm3.

[0026] Advantageously, the press 2 further comprises a conveyor system 18 comprising a conveyor belt 20 for the stamped sheet metal 10, said system 18 being able to be arranged on a floor 3 of the stamping press 2 (as illustrated), or fixed to the frame 4 of said press 2.

[0027] At the end of the stamping cycle (after the press 2 has reopened), a robot (not shown) ensures the unloading of the press 2, by moving the stamped sheet 10 from the lower frame 6 to be placed on the conveyor belt 20.

[0028] Advantageously, the present invention proposes the use of the compressed fluid to actuate the movement of the conveyor belt 20, which makes it possible to exploit this previously wasted energy.

[0029] To do this, the conveyor system 18 is equipped with rotation means (illustrated in [Fig.2]) for rotating the conveyor belt 20. These devices comprise a transmission shaft equipped with a turbine 22 (cased) designed to rotate said transmission shaft, thanks to the action of the compressed fluid coming from the fluid reservoir 16.

[0030] Preferably, the press 2 comprises a closed fluid circuit 24 comprising the fluid reservoir 16, the balancers 14 and the turbine 22. This circuit 24 makes it possible to ensure the recycling of the compressed fluid coming from the balancers 14 when the press 2 is closed, where said compressed fluid is configured to circulate in a closed loop following each stamping cycle.

[0031] The closed circuit 24 comprises a conduit 26 for conveying the compressed fluid from each of the balancers 14 to the reservoir 16 and vice versa, and also comprises a fluid outlet conduit 28 extending from said reservoir 16 to the turbine 22, and a fluid outlet conduit 30 extending from said turbine 22 to said reservoir 16. The conveying conduit 26 preferably ensures back-and-forth movements of the fluid from and to the corresponding balancer 14.

[0032] In this configuration, the closed circuit 24 makes it possible to take advantage of the mechanical energy of displacement of the pressurized fluid, to set the conveyor belt in motion.

[0033] Preferably, each of the fluid outlet ducts 28 and 30 is provided with an electrically controlled one-way valve 32 capable of being controlled by a control and command unit (not illustrated) preferably corresponding to an industrial programmable logic controller “PLC”, which can also manage the control of the automated movements of the upper frame 12.

[0034] The control of the one-way valve 32 arranged at the level of the outlet duct 28 is preferably conditioned by a measurement of the pressure of the fluid in the reservoir 16, in order to allow the circulation of the fluid towards the turbine 22 only from a pressure greater than or equal to a predetermined threshold. This makes it possible to optimize the circulation of the fluid towards the turbine 22 in order to guarantee a mechanical rotational force which is optimal for the supply of the conveyor belt 20.

[0035] [Fig. 2] represents a schematic view of the stamping press 2 of [Fig. 1]. The arrows drawn on the different conduits 26, 28, 30 represent the direction of circulation of the fluid in the closed circuit 24, in particular when the press 2 is closed.

[0036] The compressed fluid may correspond to air or oil, and more preferably corresponds to compressed air.

[0037] Advantageously, the circulation of the compressed fluid towards the turbine 22 allows the generation of a rotational movement of the transmission shaft 34 (illustrated in dotted lines), causing the conveyor belt 20 of the conveyor system 18 to start moving.

[0038] The turbine 22 preferably comprises blades extending radially over at least 50 mm and at most 200 mm, and preferably over approximately 100 mm.

[0039] In this configuration, the transmission shaft 34 may comprise a direct mechanical connection with the belt 20, thus driving the latter mechanically thanks to the rotation of the shaft 34. Preferably, the transmission shaft 34 is connected to an electric generator rotor (not shown) making it possible to generate electrical energy to power an electric motor M of the conveyor system 18.

[0040] The rotation of the turbine 22 can allow operation in addition to the conveyor belt 20, thus reducing energy consumption, or operate autonomously without requiring an external power supply (without using the electric motor M).

[0041] At the end of the stamping cycle, the vertical rise of the upper frame 12 towards its initial position is followed by a return of the fluid towards the reservoir 16, just after the passage of said fluid through the turbine 22.

[0042] Thus, the reservoir 16 serves as a reserve of compressed fluid, ready to be reused during the next stamping cycle. This configuration guarantees efficient and continuous use of the compressed fluid, allowing the constant propulsion of the conveyor belt 20 without requiring additional electrical energy. In addition, it maintains a compressed fluid pressure high enough to facilitate the raising of the press 2 during its working cycle, which makes it possible to minimize the energy consumption by the motor of the press 2.

[0043] The control and command unit makes it possible to supervise and ensure the efficient operation of the entire conveyor system 18, in particular by collecting relevant data which provides information on the performance of the electric generator, the pressure of the compressed fluid and other key parameters in order to carry out a detailed analysis of the operation of the invention, which facilitates the early detection of potential problems or performance deviations to take corrective measures in a timely manner, and provides information for preventive maintenance. To do this, control software and real-time analysis algorithms are preferably used by the control and command unit.

[0044] Advantageously, the stamping method of the invention exploits the increase in pneumatic pressure during the stamping cycle of the press 2 to capture and efficiently use the energy generated.

[0045] For this purpose, the compressed fluid is directed to the electric generator, which converts the pneumatic energy into rotational movement of the transmission shaft 34 to drive the conveyor belt 20. Thus, the present invention provides an efficient, reliable and safe solution for exploiting the pneumatic energy generated in the balancers 14.

Claims

Claims

1. Stamping press (2) for sheet metal (10) comprising: - a main and stationary frame (4); - a lower frame (6), fixed with the frame (4); - an upper frame (12), movable vertically relative to the frame (4) and to the lower frame (6); - a damping system (8) for the movement of the upper frame (12), comprising balancing cylinders (14) connected to said upper frame (12) and fluidically connected to a fluid reservoir (16) to balance the pressure within said balancing cylinders (14);characterized in that said stamping press (2) further comprises: - a conveyor system (18) comprising a conveyor belt (20) for the stamped sheet metal (10), and means for rotating said conveyor belt (20) comprising a transmission shaft (34) provided with a turbine (22) configured to rotate said transmission shaft (34), by the action of a compressed fluid coming from the fluid reservoir (16), so as to set the conveyor belt (20) in motion.;

2. Stamping press (2) according to claim 1, wherein the means for rotating the conveyor belt (20) further comprise an electric motor (M), and the transmission shaft (34) comprises an electric generator rotor capable of converting the rotation of the turbine (22) into electrical energy, so as to power said electric motor (M).

3. Stamping press (2) according to one of claims 1 and 2, in which the fluid reservoir (16), the balancing cylinders (14) and the turbine (22), form a closed circuit (24) for recycling the compressed fluid, where said compressed fluid is configured to circulate in a closed loop following each stamping cycle of said stamping press (2).

4. Stamping press (2) according to claim 3, in which the closed circuit (24) for recycling the compressed fluid comprises a fluid outlet conduit (28) extending from the reservoir (16) towards the turbine (22), and a fluid outlet conduit (30) extending from said turbine (22) towards said fluid reservoir (16).

5. A stamping press (2) according to claim 4, wherein each the fluid outlet (28) and outlet (30) conduits are provided with an electrically controlled one-way valve (32).

6. Stamping press (2) according to claim 5, further comprising a control and command unit configured to control the one-way valve (32), as a function of a pressure threshold of the fluid in the fluid reservoir (16).

7. Stamping press (2) according to one of claims 1 to 6, in which the compressed fluid corresponds to compressed air.

8. Method for stamping sheet metal (10) carried out by a stamping press (2) according to one of claims 1 to 7, and comprising the following steps: - vertical descent of the upper frame (12) towards the lower frame (6) to stamp the sheet metal (10); - compression of the fluid of the balancing cylinders (14) to maintain a balanced load and an essentially constant pressure on the sheet metal (10); - circulation of the compressed fluid from the corresponding balancing cylinder (14) towards the fluid reservoir (16); - circulation of the compressed fluid from the fluid reservoir (16) towards the turbine (22); - generation of a rotational movement of the transmission shaft (34), causing the conveyor belt (20) of the conveyor system (18) to be set in motion.

9. A stamping method according to claim 8, wherein the step of circulating the compressed fluid from the fluid reservoir (16) to the turbine (22) is conditioned by a measurement of the pressure of the fluid in said fluid reservoir (16), followed by an activation of the circulation of the compressed fluid by means of an electrically controlled one-way valve (32), when the measured pressure is greater than or equal to a predetermined threshold.

10. Stamping method according to one of claims 8 and 9, further comprising a step of vertically raising the upper frame (12), followed by a return of the fluid to the fluid reservoir (16), just after the passage of said fluid through the turbine (22).

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