Stamping press incorporating an energy recovery device

Abstract

The invention relates to a stamping press comprising a base having an upper receiving face, a lower die overhanging said upper receiving face, and an upper die carried by a plate mounted to slide vertically relative to this base, said press also comprising a hydraulic energy recovery device (200) comprising: - a flexible membrane (220) filled with an incompressible liquid and arranged between said upper receiving face of the base and said lower die, - a hydraulic turbine (270), and: - an outlet conduit (260) fluidly connecting said membrane to the inlet of said turbine, said membrane being configured to be at least partially compressed by said lower die when said upper die is lowered against the latter so as to cause extraction, via said outlet conduit (260),of a portion of the liquid contained in said membrane and its displacement towards said hydraulic turbine. Figure to be published with the abbreviation: Fig. 2,

Description

Title of the invention: Stamping press incorporating an energy recovery device technical field

[0001] The present invention relates, in general, to the field of stamping presses specially designed to deform materials, generally sheets of metal, in order to give them a specific shape. It relates in particular to such a stamping press with energy recovery. Previous technique

[0002] Stamping presses are widely used in the automotive sector for manufacturing vehicle body parts with complex curved shapes such as door panels, hoods, fenders, roof panels, tailgates, and other exterior components.

[0003] Such presses have a robust and often massive structure to withstand the significant forces generated during the stamping process. They can be of different types, such as mechanical, hydraulic, or servo-electric presses.

[0004] Deep drawing is a process in which compressive forces are applied to a sheet metal part using an upper die and a lower die that slide relative to each other and sandwich the sheet to deform it and give it the desired profile.

[0005] In order to maximize energy efficiency, various solutions are known for exploiting the energy generated by these stamping presses.

[0006] Regenerative braking systems can thus be used to convert the kinetic energy generated during braking or slowing down of one of the matrices into electrical energy that can be reinjected into the plant's electrical network.

[0007] Document EP 1 882 534 B1 proposes to convert the mechanical energy of the press into electrical energy, storing it for later use in the padding of the die during the pressing cycle in order to avoid deformation of the parts.

[0008] Energy storage devices, such as batteries or flywheels, can also be used to accumulate the energy generated during the stamping process and converted into electrical energy using piezoelectric materials. This stored energy can be reused later by the press when needed or used by other machines.

[0009] The heat produced with each press stroke can also be recovered via a network of exchangers and then reinjected into heating equipment, for example, for heating buildings.

[0010] These known energy recovery techniques unfortunately have certain limitations, particularly in terms of design and implementation costs, because they require relatively significant modifications to existing infrastructures and / or the use of expensive energy collection and conversion devices whose efficiency is relatively low. Description of the invention

[0011] The present invention aims to improve the situation.

[0012] For this purpose, it proposes a stamping press comprising a base having an upper receiving face, a lower die overhanging said upper receiving face, and an upper die carried by a plate mounted to slide vertically vis-à-vis this base; characterized in that it also includes a hydraulic energy recovery device comprising: - a flexible membrane filled with an incompressible liquid and arranged between said upper face receiving the base and said lower matrix, - a hydraulic turbine, and: - an outlet conduit fluidly connecting said membrane to the inlet of said turbine, said membrane being configured to be at least partially compressed by said lower matrix when said upper matrix is ​​lowered against the latter so as to cause the extraction, via said outlet conduit, of a part of the liquid contained in said membrane and its displacement in the direction of said hydraulic turbine.

[0013] Such an energy recovery device has the advantage of being easily integrated into a conventional stamping press without requiring significant structural modifications. Furthermore, its energy efficiency is higher than that of known devices, since the recovered energy is transformed by the turbine into mechanical energy that can be directly used to power other types of devices, such as a belt conveyor.

[0014] According to preferred characteristics of said stamping press according to the invention: - said energy recovery device includes a reservoir located higher than said membrane and fluidically connected to the outlet of said hydraulic turbine by a connecting pipe so as to receive the liquid having passed through this turbine; - said energy recovery device includes an inlet pipe fluidly connecting said reservoir to said membrane; - said inlet pipe is fitted with a non-return valve allowing circulation liquid only in the direction from said reservoir towards said membrane; - said outlet pipe is provided with a non-return valve allowing the flow of liquid only in the direction from said diaphragm to said hydraulic turbine; - said energy recovery device comprises a rigid mat resting fixedly against said upper face of the base, said mat defining a recess extending from its lower face and housing the main part of said membrane, the upper part of said mat extending above said recess having a plurality of perforations through which hollow protrusions of said membrane are fluidly connected to its main part, said protrusions protruding above said mat forming liquid-filled bubbles intended to be compressed by said lower matrix when said upper matrix is ​​lowered against the latter; - said energy recovery device includes elastic return means capable of maintaining said lower matrix, in the absence of compressive forces exerted against it by said upper matrix, away from said mat so that its lower face is flush with the top of said bubbles without exerting any compressive force on the latter; and / or - said outgrowths and said perforations are arranged regularly in rows and columns so as to form a grid.

[0015] The invention also relates in a second aspect to a sub-assembly comprising such a stamping press and a belt conveyor, said turbine comprising a rotor whose shaft is coupled to one of the reversing rollers of said conveyor so as to ensure its drive.

[0016] According to an advantageous feature, the coupling between the rotor shaft of said turbine and that of said reversing roller of the belt conveyor is ensured by means of a mechanical gear reducer so as to allow adjustment of the forward speed of this conveyor. Brief description of the drawings

[0017] The description of the invention will now be continued by a detailed description of an exemplary embodiment, given below by way of illustration but not limitation, with reference to the accompanying drawings, on which: - [Fig.1] represents a perspective view of a sub-assembly comprising a hydraulic energy recovery stamping press according to the invention coupled to a belt conveyor; - [Fig.2] is a perspective view of the hydraulic energy recovery device included in the stamping press of [Fig.1]; - [Fig.3] represents a perspective view from under the carpet and matrix that comprise the energy recovery device of [Fig.2]; - [Fig.4] is an enlarged sectional view of the carpet and matrix of [Fig.3], taken at the level of one of the orifices of this carpet; - [Fig.5] and [Fig.6] represent elevation views of the stamping press of [Fig.1] illustrating the operation of the hydraulic energy recovery device of [Fig.2] during the lowering and raising phases of the upper die. Description of the implementation methods

[0018] Fig. 1 represents a perspective view of a subassembly 1 comprising a hydraulic energy recovery stamping press 100 according to the invention coupled to a belt conveyor 300 whose operation is ensured by the energy in hydraulic form recovered by this stamping press 100.

[0019] The stamping press 100 comprises a frame 110 consisting of a parallelepiped-shaped base 111 resting on the ground and having a receiving upper face 11 IA (see figures 5 and 6), a head 112 extending above this base 111 vertically below it, and four cylindrical guide uprights 113 extending vertically between the base 111 and the head 112 at their four corners.

[0020] A generally rectangular plate 120 is mounted to slide vertically between the base 111 and the head 112 of this chassis 110 by means of four holes arranged at its four corners and through which the guide uprights 113 pass.

[0021] The sliding movement of this plate 120 is for example ensured by hydraulic actuation means using a pressurized fluid to generate the force necessary for stamping.

[0022] As illustrated by [Fig.5], the lower receiving face 120A of this tray 120 carries an upper matrix 130 while a lower matrix 140 overhangs the upper receiving face 11 IA of the base 111.

[0023] According to the invention, the stamping press 100 also includes a hydraulic energy recovery device 200 enabling the operation of the belt conveyor 300 intended to transport the sheets of metal to be stamped to this press 100.

[0024] Represented alone on [Fig.2], this energy recovery device 200 comprises a rigid mat 210 made for example of a metallic material and resting fixedly against the upper receiving face 11 IA of the base 111 below the lower matrix 140.

[0025] As illustrated by [Fig.3], the mat 210 defines a recess 211 extending from its underside and housing the main part 221 of a flexible membrane 220 filled with an incompressible liquid L such as water (see [Fig.4]).

[0026] With reference to figures 2 and 4, the upper part of this mat 210 extending above the recess 211 has a plurality of cylindrical holes 212 opening onto this recess 211.

[0027] This flexible membrane 220, arranged thus between the upper receiving face 11 IA of the base 111 and the lower matrix 140, also includes several hollow protrusions 222 fluidly connected to its main part 221, these protrusions 222 passing through the perforations 212 and protruding above the mat 210 forming bubbles 223 filled with liquid L.

[0028] As illustrated by [Fig.2], these protrusions 222 and these perforations 212 are preferably arranged regularly in rows and columns so as to form a grid.

[0029] In order to facilitate the sliding of the protrusions 222 and the bubbles 223, the inner face and the peripheral perimeter of these holes 212 are advantageously covered with an anti-friction coating 214 as shown in [Fig.4].

[0030] This coating 214 is preferably made of an elastomeric material in order to absorb any variations in size and shape of the bubbles 223, so as to guarantee a uniform sliding of the protrusions 222 through the conveyor belt 210 during the lowering and raising operations of the upper matrix 130.

[0031] To avoid any risk of tearing during compression phases, the membrane 220 is advantageously made of a thermoplastic elastomer, silicone rubber, polyurethane, or a flexible polymer. Its compressive strength can also be reinforced by the addition of natural and / or synthetic fibers such as glass or fabric fibers.

[0032] Its thickness will be chosen so as to offer an optimum compromise between mechanical resistance to compression and flexibility.

[0033] As illustrated by [Fig.6], in the absence of compressive forces exerted against it by the upper matrix 130, the lower matrix 140 is held by elastic return means 230 away vertically from the mat 210 so that its lower face is flush with the top of the bubbles 223 without exerting any compressive force on the latter.

[0034] These elastic return means are for example made up of four helical compression springs 230 arranged vertically between the upper face of the mat 210 and the lower face of the lower matrix 140 at the level of their corner areas.

[0035] With further reference to [Fig.2], the energy recovery device 200 also comprises: - an inlet conduit 240 in fluidic communication at one end with the main part 221 of the membrane 220 and whose other end is fluidically connected to the lower part of a reservoir 250 located higher than this membrane 220; and - an outlet conduit 260 in fluidic communication at one end with the main part 221 of the membrane 220 and whose other end is fluidically connected to the inlet of a hydraulic turbine 270.

[0036] The inlet pipe 240 is provided with a non-return valve 241 allowing the circulation of the liquid L only in the direction from the reservoir 250 to the membrane 220.

[0037] Similarly, the outlet pipe 260 is provided with a non-return valve 261 allowing the circulation of the liquid L only in the direction from the diaphragm 220 to the hydraulic turbine 270.

[0038] This hydraulic turbine 270, the outlet of which is fluidly connected to the upper part of the reservoir 250 by means of a connecting pipe 280, comprises an internal bladed rotor (not visible) whose shaft is coupled to one of the cylindrical turning rollers of the belt conveyor 300, so as to ensure its drive.

[0039] This coupling between the rotor shaft of the turbine 270 and that of the reversing roller of the belt conveyor 300 is advantageously ensured by means of a mechanical gear reducer 290, so as to allow adjustment of the forward speed of this conveyor 300.

[0040] We will now quickly describe the operation of the energy recovery device 200 using Figures 5 and 6.

[0041] When the sliding plate 120 carrying the upper die 130 is lowered by the actuation means of the press 100 to perform the stamping of a sheet metal part not shown, the mechanical compressive force suffered by the lower die 140 also causes it to be lowered against the elastic return means 230 so that its lower face crushes the bubbles 223 of the membrane 220 protruding above the belt 210 ([Fig.5]).

[0042] This crushing of the bubbles 223 results in the extraction, via the outlet pipe 260, of a part of the liquid L contained in this membrane 220 out of the latter and its movement towards the hydraulic turbine 270 whose rotor it will drive in rotation so as to cause the conveyor belt 300 to advance (conversion of hydraulic flow energy into rotational energy).

[0043] After passing through this hydraulic turbine 270, this liquid L then flows into the connecting pipe 280 and is discharged into the reservoir 250.

[0044] It will be noted that the non-return valve 241 of the inlet pipe 240 prevents the liquid L to escape from membrane 220 via this inlet pipe 240 during this bubble crushing phase 223.

[0045] Once the sheet metal part has been stamped, the sliding plate 120 carrying the upper die 130 is raised by the press actuating means 100 ([Fig. 6]). Activated solely by the elastic return means 230, the lower die 140 returns to its raised rest position, while the bubbles 223, no longer subjected to the compression of this lower die 140, also return to their initial position. The liquid L contained in the reservoir 250 then naturally flows by gravity into the inlet pipe 240 and returns to the membrane 220, thus refilling these bubbles 223.

[0046] It will be noted that the non-return valve 261 of the outlet pipe 260 prevents the liquid L from escaping from the turbine 270 to return to the membrane 220 via this outlet pipe 260 when the bubbles 223 return to their initial position.

[0047] At each stamping cycle, it is understood that the conveyor belt 300 will advance sequentially thanks to the energy recovery device 200 whose design and arrangement make it possible not to interfere with the trajectory of transfer robots not shown and ensuring the transport of the sheet metal part to be stamped between the press 100 and this conveyor 300.

[0048] According to alternative embodiments not shown, an energy storage mechanism, for example of the flywheel type, could be integrated into the energy recovery device 200 in order to ensure continuous movement of the conveyor belt 300.

[0049] According to other embodiments not shown, the energy recovered by means of device 200 could be used to participate in or to fully provide the energy supply of other types of devices.

[0050] The shape, dimensions and / or spacing of the bubbles can also be adjusted according to the amount of hydraulic energy that one wishes to recover.

[0051] Many variants are conceivable and it is recalled in this regard that the present invention is not limited to the embodiments described and represented, but also encompasses all variants of execution within the reach of a person skilled in the art.

Claims

Demands

1. Stamping press (100) comprising a base (111) having an upper receiving face (11 IA), a lower die (140) overhanging said upper receiving face (11 IA), and an upper die (130) carried by a plate (120) mounted to slide vertically opposite this base (111);characterized in that it also comprises a hydraulic energy recovery device (200) including: - a flexible membrane (220) filled with an incompressible liquid (L) and arranged between said upper receiving face (11 IA) of the base (111) and said lower matrix (140), - a hydraulic turbine (270), and: - an outlet conduit (260) fluidly connecting said membrane (220) to the inlet of said turbine (270), said membrane (220) being configured to be at least partially compressed by said lower matrix (140) when said upper matrix (130) is lowered against the latter so as to cause the extraction, via said outlet conduit (260), of a part of the liquid (L) contained in said membrane (220) and its displacement in the direction of said hydraulic turbine (270).

2. Stamping press (100) according to claim 1, characterized in that said energy recovery device (200) comprises a reservoir (250) located higher than said membrane (220) and fluidically connected to the outlet of said hydraulic turbine (270) by a connecting pipe (280) so as to receive the liquid (L) having passed through this turbine (270).

3. Stamping press (100) according to claim 2, characterized in that said energy recovery device (200) comprises an inlet conduit (240) fluidly connecting said reservoir (250) to said membrane (220).

4. Stamping press (100) according to claim 3, characterized in that said inlet pipe (240) is provided with a non-return valve (241) allowing the circulation of the liquid (L) only in the direction from said reservoir (250) to said membrane (220).

5. Stamping press (100) according to any one of claims 1 to 4, characterized in that said outlet pipe (260) is provided with a non-return valve (261) allowing the circulation of the liquid (L) only in the direction from said membrane (220) to said hydraulic turbine (270).

6. A stamping press (100) according to any one of claims 1 to 5, characterized in that said energy recovery device (200) comprises a rigid mat (210) fixedly resting against said upper receiving face (11 IA) of the base (111), said mat (210) defining a recess (211) extending from its lower face and housing the main portion (221) of said membrane (220), the upper portion of said mat (210) extending above said recess (211) having a plurality of perforations (212) through which hollow protrusions (222) of said membrane (220) pass, fluidly connected to its main portion (221), said protrusions (222) projecting above said mat (210) by forming bubbles (223) filled with liquid (L) intended to be compressed by said lower matrix (140) when said upper matrix (130) is lowered against the latter.

7. Stamping press (100) according to claim 6, characterized in that said energy recovery device (200) comprises elastic return means (230) capable of maintaining said lower die (140), in the absence of compressive forces exerted against it by said upper die (130), away from said belt (210) so that its lower face is flush with the top of said bubbles (223) without exerting compressive force on the latter.

8. Stamping press (100) according to any one of claims 6 or 7, characterized in that said protrusions (222) and said holes (212) are arranged regularly in rows and columns so as to form a grid.

9. Subassembly (1) comprising a stamping press (100) according to any one of claims 1 to 8 and a belt conveyor (300), said turbine (270) comprising a rotor whose shaft is coupled to one of the turning rollers of said conveyor (300) so as to ensure its drive.

10. Subassembly (1) according to claim 9, characterized in that the coupling between the rotor shaft of said turbine (270) and that of said reversing roller of the belt conveyor (300) is ensured by means of a mechanical gear reducer (290) so as to allow adjustment of the forward speed of this conveyor (300).

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