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 sheet metal stamping press (2) (10) comprising: - an upper frame (12), movable vertically relative to a fixed chassis (4), and to a lower frame (6); - a damping system (8) for the movement of the upper frame, comprising balancing cylinders (14) connected to said upper frame and fluidly connected to a fluid reservoir (16) to equalize the pressure within said balancing cylinders; remarkable in that said stamping press further comprises: - a conveyor system (18) comprising a conveyor belt (20) for the stamped sheet metal, and a drive shaft provided with a turbine (22) configured to rotate said drive shaft, by the action of a compressed fluid from the fluid reservoir, so as to move the belt conveyor. (Figure to be published with the abbreviation: Figure 1)

Description

Title of the invention: Stamping press equipped with a conveying 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. Previous technique

[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 removing the finished parts, for example, to stacking areas.

[0003] Existing conveyor belt power supply solutions often rely on independent electric motors, hydraulic systems, or external power sources. This leads to increased electricity consumption and greater 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 Al discloses a press equipped with a die damping system which includes a damping pad and hydraulic cylinders controlled by electric motors, said press is 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 allow, for example, to power the movement of a conveyor belt of a stamped sheet metal conveyor. Description of the invention

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

[0007] For this purpose, the invention relates to a sheet metal stamping press comprising: - a main and fixed frame; - a lower frame, fixed to the chassis; - an upper frame, movable vertically in relation to the chassis and the lower frame; - a system for damping the movement of the upper frame, comprising balancing cylinders connected to said upper frame and fluidically connected to a fluid reservoir to equalize the pressure within said balancing cylinders; notable in that said stamping press further comprises: - a conveyor system comprising a conveyor belt for stamped sheet metal, and means for rotating said conveyor belt comprising a drive shaft equipped with a turbine configured to rotate said drive shaft, by the action of a compressed fluid 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 conveyor belt rotation means further include an electric motor, and the transmission shaft includes an electric generator rotor capable of converting the turbine rotation 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 compressed fluid recycling circuit includes 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 supply and outlet conduits is provided with an electrically controlled one-way valve.

[0013] According to one embodiment, the stamping press further comprising a control and command unit configured to control the one-way valve, based on 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 sheet metal stamping process 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 in the balancing cylinders to maintain a balanced load and essentially constant pressure on the sheet metal; - circulation of 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 fluid pressure 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 comprising a step of vertical raising of the upper frame, followed by a return of the fluid to the fluid reservoir, just after the passage of said fluid 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 efficiency of the stamping press.

[0019] Indeed, the movement of the conveyor belt by the action of the compressed fluid 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 motion damping system of the upper frame;

[0021] [Fig.2] represents a schematic view of the stamping press of [Fig.1]. Detailed description

[0022] Fig. 1 represents a perspective view of a sheet metal stamping press 2 according to the invention.

[0023] The press 2 comprises a fixed main frame 4 with a lower frame 6 on which the sheet 10 to be stamped is placed, and also comprises an upper frame 12 movable vertically (along the Z axis) relative to the frame 4 and the lower frame 6. Reference is generally made to a closing or 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 equipped with a damping system 8 for the movement of the upper frame 12, comprising balancing cylinders 14, generally referred to as: balancers 14, connected to said upper frame 12 and fluidly 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, resulting in a pressure increase. To prevent imbalances in the press due to overpressure, the pressurized fluid is directly routed to the reservoir 16 to accumulate and help maintain a substantially constant pressure inside each balancer 14. Preferably, the fluid reservoir 16 has a total fluid accumulation capacity of between 5 dm³ and 50 dm³.

[0026] Advantageously, the press 2 further comprises a conveyor system 18 including a conveyor belt 20 for the stamped sheet 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 been reopened), a robot (not shown) unloads the press 2, 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 power 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]) enabling the conveyor belt 20 to rotate. These devices include a drive shaft equipped with a turbine 22 (shrouded) designed to rotate said drive shaft, thanks to the action of the compressed fluid from the fluid reservoir 16.

[0030] Preferably, the press 2 includes a closed fluidic 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 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 includes a conveying conduit 26 for the compressed fluid from each of the balancers 14 to the reservoir 16 and vice versa, and also includes a supply conduit 28 for the fluid extending from said reservoir 16 to the turbine 22, and a supply conduit 30 for the fluid extending from said turbine 22 to said reservoir 16. The conveying conduit 26 preferentially ensures back-and-forth movements of the fluid to and from the corresponding balancer 14.

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

[0033] Preferably, each of the fluid supply ducts 28 and outlet 30 is equipped with a unidirectional electrically controlled 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 automated movements of the upper frame 12.

[0034] The control of the one-way valve 32 arranged at the outlet duct 28 is preferably conditioned by a measurement of the fluid pressure in the reservoir 16, in order to allow fluid circulation to the turbine 22 only when the pressure is greater than or equal to a predetermined threshold. This optimizes fluid circulation to the turbine 22 to ensure optimal mechanical rotational force for feeding the conveyor belt 20.

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

[0036] The compressed fluid can be air or oil, and more preferably is 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 move.

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

[0039] In this configuration, the transmission shaft 34 may include a direct mechanical link with the belt 20, thus driving the latter mechanically through the rotation of the shaft 34. Preferably, the transmission shaft 34 is connected to an electric generator rotor (not shown) allowing the generation of 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 external power supply (without using the electric motor M).

[0041] At the end of the stamping cycle, the vertical return of the upper frame 12 to its initial position is followed by a return of the fluid to 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 ensures efficient and continuous use of the compressed fluid, allowing the constant propulsion of the conveyor belt 20 without requiring additional electrical power. Furthermore, it maintains a sufficiently high compressed fluid pressure to facilitate the upward movement of press 2 during its work cycle, thereby minimizing energy consumption by the press 2 motor.

[0043] The control and command unit allows for the supervision and efficient operation of the entire conveyor system 18, in particular by collecting relevant data that provides information on the performance of the electric generator, the pressure of the compressed fluid, and other key parameters in order to perform a detailed analysis of the operation of the invention. This facilitates the early detection of potential problems or performance deviations, enabling timely corrective action and providing information for preventive maintenance. To this end, control software and real-time analysis algorithms are preferably used by the control and command unit.

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

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

Claims

Demands

1. Sheet metal stamping press (2) (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 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 fluidly 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 (10), and means for rotating said conveyor belt (20) comprising a drive shaft (34) provided with a turbine (22) configured to rotate said drive shaft (34), by the action of a compressed fluid 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 conveyor belt rotation means (20) further comprise an electric motor (M), and the drive 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 any one of claims 1 and 2, wherein 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, wherein the closed circuit (24) for recycling the compressed fluid comprises a fluid outlet conduit (28) extending from the reservoir (16) to the turbine (22), and a fluid outlet conduit (30) extending from said turbine (22) to said fluid reservoir (16).

5. Stamping press (2) according to claim 4, wherein each The fluid supply (28) and outlet (30) conduits are provided with an electrically operated one-way valve (32).

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

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

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

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 fluid pressure 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 any one of claims 8 and 9, further comprising a step of vertical raising of 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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