EP4255652A1

EP4255652A1 - Apparatus and method for forming shape of metal foil products with wrinkleless surface

Info

Publication number: EP4255652A1
Application number: EP20963972.3A
Authority: EP
Inventors: Luen Chow Chan; Pengfei Zheng; Ting Fai KONG; Shui Yuk TONG; Tin Loi LUI
Original assignee: Beta Pack International Ltd; Hong Kong Polytechnic University HKPU
Current assignee: Beta Pack International Ltd; Hong Kong Polytechnic University HKPU
Priority date: 2020-12-04
Filing date: 2020-12-04
Publication date: 2023-10-11
Also published as: CN116867582A; WO2022116126A1; EP4255652A4

Abstract

The present disclosure provides an apparatus (100) and a method for forming a shape of a metal foil (250) product from a blank. The apparatus (100) comprises a forming tool (110) comprising a die (210), a punch (220) and a pressing plate (230). The punch (220) comprises a channel (222) located within the punch (220) and having an inlet (223) and an outlet (224), the outlet (224) is located on the forming surface for allowing a fluid to be injected into an enclosed space (354) created by at least the punch (220) and the central portion (252) of the blank for filling the enclosed space (354) to develop a hydraulic pressure (355) for pushing the central portion (252) of the blank into the die cavity (211) of the die (210) for forming the shape of the product, thereby forming the product with smooth surface and without cracks and wrinkles.

Description

APPARATUS AND METHOD FOR FORMING SHAPE OF METAL FOIL PRODUCTS WITH WRINKLELESS SURFACE

TECHNICAL FIELD

The present disclosure generally relates to an apparatus and a method for forming a shape of a metal foil product.

BACKGROUND

Metal foils have many good properties, such as low chemical sensitivity, low air and humidity permeability and resistance to high-temperature application environments so they have a wide range of applications, such as food packaging, electronic packaging materials, food container, and decoration and building materials.
The metal foil is generally made of a metal having good elongation property, such as aluminum, steel, tin, gold, high ductility stainless steel and low carbon steel. The conventional metal forming technology can be applied to the forming of metal foil containers, but it will also produce many undesirable effects, such as severe wrinkles and easy cracking. Other methods, such as free progressive forming, can also form metal foil containers, but the production efficiency is low, the cost is high, and the surface is not smooth. Another forming method is hydroforming. When applied to metal sheets, this method can provide good forming effects. Nevertheless, it produce many undesirable effects, such as cracking or shape rebound of product when applied to metal foils.
A need therefore exists for an improved apparatus and method for forming a shape of a product that eliminates or at least diminishes the disadvantages and problems described above.
SUMMARY OF THE INVENTION
Provided herein is an apparatus for forming a shape of a product from a blank comprising: a forming tool comprising: a die comprising a die cavity and a die shoulder, the die shoulder being located adjacent to the die cavity and used for holding a peripheral portion of the blank; a punch for pushing a central portion of the blank toward the die cavity; and a pressing plate for pressing the peripheral portion of the blank against the die shoulder, the pressing plate comprising a hole for allowing the punch to move along the hole to push the central portion of the blank, the hole and the punch being configured to avoid a fluid leakage between the pressing plate and the punch; wherein the punch comprises a channel located within the punch and having an inlet and an outlet, the inlet and the outlet being arranged to allow a fluid to be injected into an enclosed space created by at least the punch and the central portion of the blank for filling the enclosed space to develop a hydraulic pressure for pushing the central portion of the blank into the die cavity for forming the shape of the product, thereby avoiding wrinkle formation on a surface of the product.
In certain embodiments, the apparatus further comprises a pump for injecting the fluid into the enclosed space.
In certain embodiments, the pump is an air pump or a liquid pump.
In certain embodiments, the punch and the hole are configured to allow the punch to be tightly-fitted to the hole.
In certain embodiments, the forming tool further comprises a sealing ring located in the hole and between pressing plate and the punch for avoiding the fluid leakage.
In certain embodiments, the enclosed space is created by the punch, the central portion of the blank and the pressing plate.
In certain embodiments, the pressing plate and the die are configured to allow the pressing plate to cover the die.
In certain embodiments, the forming tool further comprises a sealing ring located between the pressing plate and the die for avoiding a fluid leakage between the pressing plate and the die.
In certain embodiments, the forming tool further comprises a first pressure sensor located on the forming surface for measuring the hydraulic pressure.
In certain embodiments, the apparatus further comprises a press machine for driving the punch to push the central portion of the blank and applying a pressing pressure to the pressing plate to press the peripheral portion of the blank against the die shoulder.
In certain embodiments, the pressing machine comprises: a first mechanical actuator for driving the punch; and one or more second mechanical actuator for applying the pressing pressure to the pressing plate.
In certain embodiments, the forming tool further comprises a second pressure sensor for measuring the pressing pressure.
In certain embodiments, the press machine further comprises: a first beam, a second beam and a movable beam located between the first beam and the second beam, the first mechanical actuator and the one or more second mechanical actuator being attached to the first beam, the forming tool being arranged to be attached to the second beam and located between the moveable beam and the second beam, a pistol of the first mechanical actuator being attached to a top of the bunch for driving the punch, one or more pistols of the one or more second mechanical actuator connecting to the moveable beam for driving the moveable beam to move toward the forming tool for applying the pressing pressure to the pressing plate.
In certain embodiments, the first mechanical actuator is a first hydraulic cylinder; and the one or more second mechanical actuators are one or more second hydraulic cylinders.
In certain embodiments, the apparatus further comprises a controller configured to: control the first mechanical actuator to drive the punch; control the pump to inject the fluid into the enclosed space; and control the one or more second mechanical actuators to apply the pressing pressure to the pressing plate.
In certain embodiments, the controller is further configured to: control the first mechanical actuator to drive the punch under a predetermined stroke distance profile; control the pump to inject the fluid into the enclosed space under a predetermined fluid working pressure profile; and control the one or more second mechanical actuator to apply the pressing pressure to the pressing plate under a predetermined pressing force profile.
In certain embodiments, the controller is further configured to: control the hydraulic pump to inject the fluid into the enclosed space under real-time measured values of the hydraulic pressure; and control the one or more second mechanical actuator to apply the pressing pressure to the pressing plate under real-time measured values of the pressing pressure.
Provided herein is a method for forming a shape of a product from a blank comprising: placing the blank on a die comprising a die cavity and a die shoulder located adjacent to the die cavity; pressing a peripheral portion of the blank against the die shoulder; pushing a central portion of the blank toward the die cavity with a punch; and injecting a fluid into an enclosed space created by at least the punch and the central portion of the blank for filling the enclosed space to develop a hydraulic pressure for pushing the central portion of the blank into the die cavity for forming the shape of the product, thereby avoiding wrinkle formation on a surface of the product.
In certain embodiments, the method further comprises: measuring the hydraulic pressure; and adjusting a fluid working pressure for injecting the fluid into the enclosed space based on the measured hydraulic pressure.
In certain embodiments, the blank is a metal foil; and the fluid is air, nitrogen gas, water or an oil.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. Other aspects of the present invention are disclosed as illustrated by the embodiments hereinafter.
BRIEF DESCRIPTION OF DRAWINGS
The appended drawings, where like reference numerals refer to identical or functionally similar elements, contain figures of certain embodiments to further illustrate and clarify the above and other aspects, advantages and features of the present invention. It will be appreciated that these drawings depict embodiments of the invention and are not intended to limit its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
Figure 1 is a block diagram depicting an apparatus for forming a shape of a product from a blank according to certain embodiments;
Figure 2A is a schematic diagram depicting a forming tool according to certain embodiments;
Figure 2B is a schematic depicting a blank pressed by the forming tool of Figure 1;
Figure 3 is cross-sectional view depicting a central portion of a foil pushed into a die cavity with a cylindrical shape according to certain embodiments;
Figure 4 is cross-sectional view depicting a central portion of a foil pushed into a die cavity with a semi-conical shape according to certain embodiments;
Figure 5 depicts an apparatus for forming a shape of a product from a blank according to certain embodiments;
Figure 6A depicts a stroke distance profile according to certain embodiments;
Figure 6B depicts a pressing pressure profile according to certain embodiments;
Figure 6C depicts a fluid working pressure profile according to certain embodiments;
Figure 7 is flow chart depicting a method for forming a shape of a product from a blank according to certain embodiments;
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been depicted to scale.

DETAILED DESCRIPTION OF THE INVENTION

As used herein in the specification and appended claims, the term “avoid” or “avoiding” refers to any method to partially or completely preclude, avert, obviate, forestall, stop, hinder or delay the consequence or phenomenon following the term “avoid” or “avoiding” from happening. The term “avoid” or “avoiding” does not mean that it is necessarily absolute, but rather effective for providing some degree of avoidance or prevention or amelioration of consequence or phenomenon following the term “avoid” or “avoiding” .
The present disclosure provides an apparatus and a method for forming a shape of a product from a blank. The present apparatus and method form the blank into a net shape mechanically and hydrostatically, thereby producing a product with smooth surface and without cracks and wrinkles. In addition, the size and accuracy of the product produced by the present invention are stable and reliable. The present apparatus and method are preferably used for forming the shape of product from a thin metal foil (e.g., below 0.2 mm in thickness) for avoiding wrinkle and crack formation in view of the fragile property of this thin metal foil.
Provided herein is an apparatus for forming a shape of a product from a blank comprising: a forming tool comprising: a die comprising a die cavity and a die shoulder, the die shoulder being located adjacent to the die cavity and used for holding a peripheral portion of the blank; a punch for pushing a central portion of the blank toward the die cavity, the punch having a forming surface located at the bottom of the punch; and a pressing plate for pressing the peripheral portion of the blank against the die shoulder, the pressing plate comprising a hole for allowing the punch to move along the hole to push the central portion of the blank, the hole and the punch being configured to avoid a fluid leakage between the pressing plate and the punch; wherein the punch comprises a channel located within the punch and having an inlet and an outlet, the inlet being located on the lateral surface of the punch and the outlet being located on the forming surface for allowing a fluid to be injected into an enclosed space created by at least the punch and the central portion of the blank for filling the enclosed space to develop a hydraulic pressure for pushing the central portion of the blank into the die cavity for forming the shape of the product, thereby avoiding wrinkle formation on a surface of the product.
In certain embodiments, the apparatus further comprises a pump for injecting the fluid into the enclosed space.
In certain embodiments, the pump is an air pump or a liquid pump.
In certain embodiments, the punch and the hole is configured to allow the punch to be tightly-fitted to the hole.
In certain embodiments, the forming tool further comprises a sealing ring located in the hole and between pressing plate and the punch.
In certain embodiments, the enclosed space is created by the punch, the central portion of the blank and the pressing plate.
In certain embodiments, the pressing plate and the die are configured to allow the pressing plate to cover the die.
In certain embodiments, the forming tool further comprises a sealing ring located between the pressing plate and the die for avoiding a fluid leakage between the pressing plate and the die.
In certain embodiments, the forming tool further comprises a first pressure sensor located on the forming surface for measuring the hydraulic pressure.
In certain embodiments, the apparatus further comprises a press machine for driving the punch to push the central portion of the blank and applying a pressing pressure to the pressing plate to press the peripheral portion of the blank against the die shoulder.
In certain embodiments, the pressing machine comprises: a first mechanical actuator for driving the punch; and one or more second mechanical actuator for applying the pressing pressure to the pressing plate.
In certain embodiments, the forming tool further comprises a second pressure sensor for measuring the pressing pressure.
In certain embodiments, the press machine further comprises: a first beam, a second beam and a movable beam located between the first beam and the second beam, the first mechanical actuator and the one or more second mechanical actuator being attached to the first beam, the forming tool being arranged to be attached to the second beam and located between the moveable beam and the second beam, one or more pistols of the one or more second mechanical actuator connecting to the moveable beam for driving the moveable beam to move toward the forming tool for applying the pressing pressure to the pressing plate.
In certain embodiments, the first mechanical actuator is a first hydraulic cylinder; and the one or more second mechanical actuators are one or more second hydraulic cylinders.
In certain embodiments, the apparatus further comprises a controller configured to: control the first mechanical actuator to drive the punch; control the pump to inject the fluid into the enclosed space; and control the one or more second mechanical actuators to apply the pressing pressure to the pressing plate.
In certain embodiments, the controller is further configured to: control the first mechanical actuator to drive the punch under a predetermined stroke distance profile having a relationship between a stroke distance of the punch and time; control the hydraulic pump to inject the fluid into the enclosed space under a predetermined hydraulic pressure profile having a relationship between the hydraulic pressure and time; and control the one or more second mechanical actuator to apply the pressing pressure to the pressing plate under a predetermined pressing pressure profile having a relationship between the pressing pressure versus time.
In certain embodiments, the controller is further configured to: control the hydraulic pump to inject the fluid into the enclosed space under real-time measured values of the hydraulic pressure; and control the one or more second mechanical actuator to apply the pressing pressure to the pressing plate under real-time measured values of the pressing pressure.
Provided herein is a method for forming a shape of a product from a blank comprising: placing the blank on a die comprising a die cavity and a die shoulder; pressing a peripheral portion of the blank against the die shoulder; pushing a central portion of the blank toward the die cavity with a punch; and injecting a fluid into an enclosed space created by at least the punch and the central portion of the blank for filling the enclosed space to develop a hydraulic pressure for pushing the central portion of the blank into the die cavity for forming the shape of the product, thereby avoiding wrinkle formation on a surface of the product.
In certain embodiments, the method further comprises measuring the hydraulic pressure and controlling a fluid working pressure for injecting the fluid into the enclosed space based on the measured hydraulic pressure.
In certain embodiments, the blank is a metal foil, a metal sheet or a metal plate. The metal foil may have a thickness below 0.2 mm, between 0.01 mm and 0.1 mm or between 0.05 mm and 0.18 mm. The metal sheet may have a thickness between 0.2 mm and 6 mm.
In certain embodiments, the blank is made of aluminum, tin, gold, silver or steel (e.g., high ductility stainless steel and low carbon steel) .
In certain embodiments, the fluid is a gas or a liquid. The gas can be the air or nitrogen gas. The liquid can be the water or an oil.
In certain embodiments, the product is a container, a food container or an electronic component capsule.
Figure 1 is a block diagram depicting an apparatus 100 for forming a shape of a product from a blank according to certain embodiments. The apparatus 100 comprises a forming tool 110, a hydraulic pump 120, a fluid tank 121, a press machine 130 and a controller 140. The hydraulic pump 120 connects to the inlet of the channel of the forming tool 110 via a tube 122 for injecting a fluid into the channel. The fluid tank 121 stores the fluid for the hydraulic pump 120 and connects to the hydraulic pump 120 via a tube 123. The press machine 130 drives the punch of the forming tool 110 to push the central portion of the blank and applies a pressing pressure to the pressing plate of the forming tool 110. The controller 140 controls the hydraulic pump 120 to inject the fluid into the channel and the press machine 130 to drive the punch and apply the pressing pressure to the pressing plate.
Figures 2A and 2B depicts a forming tool 200 for forming a shape of a product from a foil 250 according to certain embodiments. The forming tool 200 comprises a die 210, a punch 220 and a pressing plate 230. The die 210 comprises a die cavity 211 and a die shoulder 212. The die cavity 211 has the shape of the product. The die shoulder 212 is located adjacent to the die cavity 211 and holds a peripheral portion 251 of the foil 250. The punch 220 pushes a central portion 252 of the foil 250 toward the die cavity 211. The punch 220 has a forming surface 221 located at the bottom (or head) of the punch 220 and facing the central portion 252 for contacting and pushing the central portion 252. The pressing plate 230 is placed on the peripheral portion 251 for pressing the peripheral portion 251 against the die shoulder 212 for holding the foil 250 on the die 210 and avoiding a fluid leakage between the pressing plate 230 and the peripheral portion 251. The pressing plate 230 comprising a hole 231 for allowing the punch 220 to move along the hole 231 to push the central portion 252. The punch 220 comprises a channel 222 located within the punch 220 and having an inlet 223 and an outlet 224. The inlet 223 is located on the lateral surface of the punch 220 and the outlet 224 is located on the forming surface 221.
In this embodiment, the forming tool 200 further comprises a first die holder 240, a second die holder 241, a four guided pins 242, two sealing rings 243a, 243b, and two pressure sensors 244a, 244b. The first die holder 240 is attached to the die 210 for holding the die 210. The second die holder 241 is attached to the pressing plate 230 for holding the pressing plate 230 and locating the punch 220. The first die holder 240 and the second die holder 241 are connected by the four guided pins 243. The sealing ring 243a is located between the pressing plate 230 and the punch 220 in the hole 231 for avoiding a fluid leakage between the pressing plate 230 and the punch 220. The sealing ring 243b is attached to the die shoulder 212 and located between the pressing plate 230 and the die shoulder 212 for avoiding a fluid leakage between the pressing plate 230 and the die shoulder 212. The pressure sensor 244a is attached to the forming surface 221 for measuring a hydraulic pressure developed in an enclosed space. The pressure sensor 244b is attached to the pressing plate 230 for measuring a pressing pressure applied to the peripheral portion 251.
Figure 3 is cross-sectional view depicting a central portion of a foil pushed into a die cavity with a cylindrical shape according to certain embodiments. A punch 320 moves downward to push a central portion 352 of a foil 350 into a die cavity 311. A liquid 353 is injected into an encloses space 354 created by the punch 320 and the central portion 352 via a channel 322 for filling the enclosed space 354 to develop a hydraulic pressure 355 for pushing the central portion 352 into the die cavity 311 for forming the shape of the product.
Accordingly, the fluid (acting as a pressure buffer) fills the enclosed space and internally expands to develop the hydraulic pressure (e.g., from 0.1 MPa to 20MPa) . Unlike the conventionally hard mechanical press from the punch, the hydraulic pressure provides a flexible and soft bulging pressure applied to the central portion of a foil for forming the foil into a product with smooth surface and without cracks and wrinkles. In addition, values of the hydraulic pressure in the enclosed space can be easily adjusted by adjusting the fluid working pressure of the pump and/or the amount of fluid injected into the enclosed space. Furthermore, as the product is formed in the die cavity having the shape of the product, the size and accuracy of the finished product are stable and reliable.
Figure 4 is cross-sectional view depicting a central portion of a foil pushed into a die cavity with a semi-conical shape according to certain embodiments. A pressing plate 430 presses a peripheral portion 451 of a foil 450 against a die shoulder 412 with a pressing pressure 456 for holding the foil 450 on the die 410 and avoiding a fluid leakage between the peripheral portion 451 and the pressing plate 430. A punch 420 having a tapered head moves downward to push a central portion 452 of the foil 450 into a die cavity 411. A liquid 453 is injected into an encloses space 454 created by the punch 420, the central portion 452 and the pressing plate 430 via a channel 422 for filling the enclosed space 454 to develop a hydraulic pressure 455 for pushing the central portion 452 into the die cavity 411 for forming the shape of the product.
Figure 5 depicts an apparatus 500 for forming a shape of a product from a blank according to certain embodiments. The apparatus 500 comprises the forming tool 200 and a press machine 510. The press machine 510 comprises a first hydraulic cylinder 520, two second hydraulic cylinders 530a, 530b, a first beam 540, a second beam 541 and a movable beam 542 located between the first beam 540 and the second beam 541. The first beam 540, the second beam 541 and the movable beam 542 are connected by four columns (not shown in this figure) . The first hydraulic cylinder 520 and the two hydraulic cylinders 530a, 530b are attached to the first beam 540. The forming tool 200 is attached to the second beam 541 and located between the moveable beam 542 and the second beam 541. A pistol 521 of the first hydraulic cylinder 520 passes through a hole 543 of the moveable beam 542 and is attached to the top of the punch 220 for driving the punch 220 to move back and forth. Two pistols 531a, 531b of the two second hydraulic cylinders 530a, 530b are attached to the moveable beam 542 for driving the moveable beam 542 to move back and forth to press the forming tool 200 for applying the pressing pressure to the pressing plate 230.
In certain embodiments, the controller adopts the synchronized closed-loop variable control for providing an optimized matching among different parameters so as to eliminate the rupture and wrinkle defects of the product.
In certain embodiments, the controller controls the first mechanical actuator to drive the punch, control the pump to inject the fluid into the enclosed space and control the second mechanical actuators to apply the pressing pressure to the pressing plate based on their respective predetermined profile.
Figure 6A depicts a stroke distance profile according to certain embodiments. The stroke distance profile shows a relationship between the stroke distance of the punch versus time for controlling the stroke distance over time during shape formation of the product. The first mechanical actuator can provide a stroke distance between 0 mm and 35 mm.
Figure 6B depicts a pressing force profile according to certain embodiments. The pressing force profile shows a relationship between the pressing force of the second mechanical actuator versus time for controlling the pressing force over time during shape formation of the product. The second mechanical actuator can provide a pressing force between 0 kN and 100 kN.
Figure 6C depicts a fluid working pressure profile according to certain embodiments. The fluid working pressure profile shows a relationship between the fluid working pressure of the pump and time for controlling the fluid working pressure of the pump over time during shape formation of the product. The pump can generate a fluid working pressure between 0 MPa and 4 MPa.
In certain embodiments, the controller is further configured to: control the hydraulic pump to inject the fluid into the enclosed space under real-time measured values of the hydraulic pressure; and control the one or more second mechanical actuator to apply the pressing pressure to the pressing plate under real-time measured values of the pressing pressure.
Figure 7 is flow chart depicting a method for forming a shape of a product from a blank according to certain embodiments. In step S71, the blank is placed on a die comprising a die cavity and a die shoulder located adjacent to the die cavity. In step S72, a peripheral portion of the blank is pressed against the die shoulder. In step S73, a central portion of the blank is pushed toward the die cavity with a punch. In step S74, a fluid is injected into an enclosed space created by at least the punch and the central portion of the blank for filling the enclosed space to develop a hydraulic pressure for pushing the central portion of the blank into the die cavity for forming the shape of the product.
In certain embodiments, the method further comprises: measuring the hydraulic pressure; and adjusting a fluid working pressure for injecting the fluid into the enclosed space based on the measured hydraulic pressure.
Thus, it can be seen that an improved apparatus and method for forming a shape of a product have been disclosed which eliminates or at least diminishes the disadvantages and problems associated with prior art apparatuses and processes. According to certain embodiments of the present disclosure, a fluid is injected into an enclosed space created by at least the punch and the central portion of the blank for filling the enclosed space to develop a hydraulic pressure for pushing the central portion of the blank into the die cavity for forming the shape of the product, thereby forming the product with smooth surface and without cracks and wrinkles. In addition, the size and accuracy of the product formed by the present apparatus and method are stable and reliable.
Although the invention has been described in terms of certain embodiments, other embodiments apparent to those of ordinary skill in the art are also within the scope of this invention. Accordingly, the scope of the invention is intended to be defined only by the claims which follow.

Claims

An apparatus for forming a shape of a product from a blank comprising:

a forming tool comprising:

a die comprising a die cavity and a die shoulder, the die shoulder being located adjacent to the die cavity and used for holding a peripheral portion of the blank;

a punch for pushing a central portion of the blank toward the die cavity; and

a pressing plate for pressing the peripheral portion of the blank against the die shoulder, the pressing plate comprising a hole for allowing the punch to move along the hole to push the central portion of the blank, the hole and the punch being configured to avoid a fluid leakage between the pressing plate and the punch;

wherein the punch comprises a channel located within the punch and having an inlet and an outlet, the inlet and the outlet being arranged to allow a fluid to be injected into an enclosed space created by at least the punch and the central portion of the blank for filling the enclosed space to develop a hydraulic pressure for pushing the central portion of the blank into the die cavity for forming the shape of the product.
The apparatus of claim 1 further comprising a pump for injecting the fluid into the enclosed space.
The apparatus of claim 2, wherein the pump is an air pump or a liquid pump.
The apparatus of claim 1, wherein the punch and the hole are configured to allow the punch to be tightly-fitted to the hole.
The apparatus of claim 1, wherein the forming tool further comprises a sealing ring located in the hole and between pressing plate and the punch for avoiding the fluid leakage.
The apparatus of claim 1, wherein the enclosed space is created by the punch, the central portion of the blank and the pressing plate.
The apparatus of claim 1, wherein the pressing plate and the die are configured to allow the pressing plate to cover the die.
The apparatus of claim 7, wherein the forming tool further comprises a sealing ring located between the pressing plate and the die for avoiding a fluid leakage between the pressing plate and the die.
The apparatus of claim 1, wherein the forming tool further comprises a first pressure sensor located on the forming surface for measuring the hydraulic pressure.
The apparatus of claim 2 further comprising a press machine for driving the punch to push the central portion of the blank and applying a pressing pressure to the pressing plate to press the peripheral portion of the blank against the die shoulder.
The apparatus of claim 10, wherein the pressing machine comprises:

a first mechanical actuator for driving the punch; and

one or more second mechanical actuator for applying the pressing pressure to the pressing plate.
The apparatus of claim 10, wherein the forming tool further comprises a second pressure sensor for measuring the pressing pressure.
The apparatus of claim 11, wherein the press machine further comprises: a first beam, a second beam and a movable beam located between the first beam and the second beam, the first mechanical actuator and the one or more second mechanical actuator being attached to the first beam, the forming tool being arranged to be attached to the second beam and located between the moveable beam and the second beam, a pistol of the first mechanical actuator being attached to a top of the bunch for driving the punch, one or more pistols of the one or more second mechanical actuator connecting to the moveable beam for driving the moveable beam to move toward the forming tool for applying the pressing pressure to the pressing plate.
The apparatus of claim 11, wherein the first mechanical actuator is a first hydraulic cylinder; and the one or more second mechanical actuators are one or more second hydraulic cylinders.
The apparatus of claim 11 further comprising a controller configured to:

control the first mechanical actuator to drive the punch;

control the pump to inject the fluid into the enclosed space; and

control the one or more second mechanical actuators to apply the pressing pressure to the pressing plate.
The apparatus of claim 15, wherein the controller is further configured to:

control the first mechanical actuator to drive the punch under a predetermined stroke distance profile;

control the pump to inject the fluid into the enclosed space under a predetermined fluid working pressure profile; and

control the one or more second mechanical actuator to apply the pressing pressure to the pressing plate under a predetermined pressing force profile.
The apparatus of claim 16, wherein the controller is further configured to:

control the hydraulic pump to inject the fluid into the enclosed space under real-time measured values of the hydraulic pressure; and

control the one or more second mechanical actuator to apply the pressing pressure to the pressing plate under real-time measured values of the pressing pressure.
A method for forming a shape of a product from a blank comprising:

placing the blank on a die comprising a die cavity and a die shoulder located adjacent to the die cavity;

pressing a peripheral portion of the blank against the die shoulder;

pushing a central portion of the blank toward the die cavity with a punch; and

injecting a fluid into an enclosed space created by at least the punch and the central portion of the blank for filling the enclosed space to develop a hydraulic pressure for pushing the central portion of the blank into the die cavity for forming the shape of the product, thereby avoiding wrinkle formation on a surface of the product.
The method of claim 18 further comprising: measuring the hydraulic pressure; and adjusting a fluid working pressure for injecting the fluid into the enclosed space based on the measured hydraulic pressure.
The method of claim 18, wherein the blank is a metal foil; and the fluid is air, nitrogen gas, water or an oil.