阅读说明：本技术 热压成形装置和用于使坯料热压成形的方法 (Hot press forming device and method for hot press forming blank ) 是由 L·桑德贝格 J·因纳拉 P·乌尔夫贝格 于 2020-04-17 设计创作，主要内容包括：本发明公开一种用于热压成形装置的方法和一种用于使坯料(104)成形的热压成形装置(102；202),所述热压成形装置(102；202)包括第一模具(106；206)和第二模具(108),其中所述第一模具(106；206)具有至少一个模腔(110；210),并且所述第二模具(108)具有至少一个模具突出部(112),其中所述热压成形装置(102；202)被配置成通过所述第一模具和第二模具(106,108；206,108)使放置在所述第一模具和第二模具(106,108；206,108)之间的所述坯料(104)压制成形。所述第一模具和第二模具(106,108；206,108)中的至少一者具有拉伸半径(116；216),其中构件(118；218)附接到具有拉伸半径(116；216)的模具(106；206)。所述构件(118；218)的至少一部分(119；219)邻近于所述拉伸半径(116；216)定位或定位在所述拉伸半径上。所述构件(118；218)限定第一压制成形表面(120；220),并且保持所述构件(118；218)的所述模具(106；206)限定在所述第一压制成形表面(120；220)之外的第二压制成形表面(122；222)。所述构件(118；218)和保持所述构件(118；218)的所述模具(106；206)被配置成使得在同一热压成形期间,当所述坯料(104)与所述构件(118；218)接触时,在所述坯料(104)与所述第一压制成形表面(120；220)之间出现第一摩擦力,并且当所述坯料(104)与保持所述构件(118；218)的所述模具(106；206)接触时,在所述坯料(104)与所述第二压制成形表面(122；222)之间出现第二摩擦力,所述第一摩擦力小于所述第二摩擦力。(The invention discloses a method for a hot press forming device and a hot press forming device (102; 202) for forming a blank (104), the hot press forming device (102; 202) comprising a first die (106; 206) and a second die (108), wherein the first die (106; 206) has at least one die cavity (110; 210) and the second die (108) has at least one die protrusion (112), wherein the hot press forming device (102; 202) is configured to press form the blank (104) placed between the first and second dies (106, 108; 206, 108) by means of the first and second dies (106, 108; 206, 108). At least one of the first and second dies (106, 108; 206, 108) has a draw radius (116; 216), wherein the member (118; 218) is attached to the die (106; 206) having the draw radius (116; 216). At least a portion (119; 219) of the member (118; 218) is positioned adjacent to or on the stretch radius (116; 216). The component (118; 218) defines a first press forming surface (120; 220) and the mould (106; 206) holding the component (118; 218) defines a second press forming surface (122; 222) outside the first press forming surface (120; 220). The component (118; 218) and the die (106; 206) holding the component (118; 218) are configured such that during the same hot press forming a first friction force occurs between the blank (104) and the first press forming surface (120; 220) when the blank (104) is in contact with the component (118; 218) and a second friction force occurs between the blank (104) and the second press forming surface (122; 222) when the blank (104) is in contact with the die (106; 206) holding the component (118; 218), the first friction force being smaller than the second friction force.)

1. A hot press forming device (102; 202) for forming a blank (104), the hot press forming device (102; 202) comprising a first die (106; 206) and a second die (108), wherein the first die (106; 206) has at least one die cavity (110; 210) and the second die (108) has at least one die protrusion (112), the die protrusion (112) of the second die (108) being complementary to the die cavity (110; 210) of the first die (106; 206), wherein the hot press forming device (102; 202) is configured to press form the blank (104) placed between the first and second dies (106, 108; 206, 108) by means of the first and second dies (106, 108; 206, 108), wherein the first and second dies (106, 108; 206, 108) has a stretch radius (116; 216) wherein the member (118; 218) is attached to a pipe having a stretch radius (116; 216) the mould (106; 206) said member (118; 218) at least a portion (119; 219) adjacent to the stretch radius (116; 216) is positioned or positioned on the stretch radius, wherein the member (118; 218) defining a first press forming surface (120; 220) and holds the member (118; 218) of the mould (106; 206) is defined in the first press forming surface (120; 220) an outer second press-formed surface (122; 222) wherein the member (118; 218) and holding the member (118; 218) of the mould (106; 206) is configured such that, during the same hot press forming, when the blank (104) is in contact with the component (118; 218) when in contact, the blank (104) is pressed against the first press forming surface (120; 220) and when the blank (104) is in contact with the retaining member (118; 218) of the mould (106; 206) when in contact, the blank (104) is pressed against the second press forming surface (122; 222) a second friction force occurs therebetween, the first friction force being less than the second friction force.

2. The thermoforming device according to claim 1, characterized in that at least a portion (119; 219) of the member (118; 218) is positioned on the drawing radius (116; 216).

3. The thermoforming device according to claim 1 or 2, characterized in that at least a part of the member (118; 218) surrounds the mold cavity (110; 210) or the mold protrusion (112).

4. A thermoforming apparatus as claimed in any of claims 1 to 3, characterised in that at least a portion of the member (118; 218) is located outside the mould cavity (110; 210) or the mould protrusion (112).

5. The thermoforming device according to any of claims 1 to 4, characterized in that the member (118) is provided as a coating applied to a mold (106) having a drawing radius (116).

6. The thermoforming device according to any of claims 1 to 4, characterized in that the member (118) is provided as a liquid which is applied to a mold (106) having a drawing radius (116) and subsequently solidified.

7. The thermoforming device according to any of claims 1 to 4, characterized in that the component (118) comprises an adhesive tape having a first surface (120) and a second surface (124), wherein the first surface (120) of the adhesive tape forms the first press forming surface (120) of the component (118) and the second surface (124) of the adhesive tape is provided with at least one adhesive substance, and wherein the second surface (124) of the adhesive tape is attached to a mold (106) having a drawing radius (116) by means of the at least one adhesive substance.

8. A thermoforming apparatus as claimed in any of claims 1 to 7, characterised in that the mould (206) having a drawing radius (216) is provided with at least one recess (226) holding the member (218).

9. The thermoforming device according to any of claims 1 to 8, characterized in that the member (218) is elastic.

10. The thermoforming device according to any of claims 1 to 9, characterized in that the first mold (106; 206) has a drawing radius (116; 216) and the member (118; 218) is attached to the first mold (106; 206).

11. A thermoforming apparatus as claimed in any of claims 1 to 10, characterised in that the member (118; 218) is a polymeric member (118; 218).

12. A thermoforming device as claimed in claim 11, characterised in that the polymer member (118; 218) is made of an elastomer or a mixture of elastomers.

13. A thermoforming apparatus as claimed in claim 11 or 12, characterised in that the polymer member (118; 218) is at least partly made of polyimide.

14. The hot press forming device according to any one of claims 1 to 13, wherein one of the first and second dies (106, 108; 206, 108) is an upper die (108) placed above the other die (106; 206) being a lower die (106; 206), at least one of the first and second dies (106, 108; 206, 108) being substantially vertically movable with respect to the other die (106, 108; 206, 108), and the substantially vertically movable die (106, 108; 206, 108) is configured to be substantially vertically movable towards the other die (106, 108; 206, 108) for press forming the blank (104).

15. A method for hot press forming a blank, the method comprising the steps of:

placing (301) the blank (104) between a first die (106) and a second die (108), wherein the first die (106) has at least one die cavity (110) and the second die (108) has at least one die protrusion (112), the die protrusion (112) of the second die (108) being complementary to the die cavity (110) of the first die (106), wherein at least one of the first die (106) and the second die (108) has a drawing radius (116), wherein a member (118) is attached to the die (106) having the drawing radius (116), at least a portion (119) of the member (118) being positioned adjacent to or on the drawing radius (116), wherein the member (118) defines a first press forming surface (120) and the die (106) holding the member (118) defines a second press forming surface (120) outside the first press forming surface (120) A contoured surface (122);

heating (302) the blank (104); and

-press-forming (303) the blank (104) placed between the first and second dies (106, 108) by means of the first and second dies (106, 108), wherein during the same hot press-forming a first friction force occurs between the blank (104) and the first press-forming surface (120) when the blank (104) is in contact with the component (118), and a second friction force occurs between the blank (104) and the second press-forming surface (122) when the blank (104) is in contact with the die (106) holding the component (118), the first friction force being smaller than the second friction force.

16. The method for hot press forming a blank according to claim 15, characterized in that one of the first and second dies (106, 108) is an upper die (108) placed above the other die (106) being a lower die (106), and in that at least one of the first and second dies (106, 108) is moved substantially vertically towards the other die (106, 108) for press forming the blank (104).

Technical Field

Aspects of the present invention relate to a hot press forming apparatus for forming a blank, wherein the hot press forming apparatus includes a first die and a second die. The first mold has at least one mold cavity and the second mold has at least one mold projection, the mold projection of the second mold being complementary to the mold cavity of the first mold. The hot press forming device is configured to press-form a blank placed between a first die and a second die by the first die and the second die. Further, aspects of the present invention relate to a method for hot press forming a blank.

Background

Hot-pressed metal parts, such as aluminum parts, are commonly used in the automotive industry for various parts of automobiles, such as sills, bumpers, support members and structures, and the like. Other application areas are also possible. When a blank is hot press formed between two dies to form a metal part, blank material may remain on the press forming surfaces of the dies after press forming. This may be referred to as "cladding" and can impair the process of hot-forming the metal part and impair the quality of the resulting metal part.

Disclosure of Invention

It is an aim of embodiments of the present invention to provide a solution which alleviates or solves the disadvantages and problems of conventional solutions.

The above and other objects of embodiments of the present invention are achieved according to a first aspect of the present invention by providing a hot press forming apparatus for forming a blank, wherein the hot press forming apparatus comprises a first die and a second die. The first mold has at least one mold cavity and the second mold has at least one mold projection. The mold projections of the second mold are complementary to the cavities of the first mold. The hot press forming device is configured to press-form a blank placed between a first die and a second die by the first die and the second die. At least one of the first die and the second die has a drawing radius. A member is attached to a mold having a drawing radius, at least a portion of the member being positioned adjacent to or on the drawing radius. The component defines a first press forming surface and the die holding the component defines a second press forming surface outside the first press forming surface. The dies of the member and the holding member are configured such that during the same hot press forming a first friction force occurs between the blank and the first press forming surface when the blank is in contact with the member and a second friction force occurs between the blank and the second press forming surface when the blank is in contact with the die holding the member. The first frictional force is less than the second frictional force. The device comprises the member as it is attached to the mould of the device.

An advantage of the device according to the first aspect is that it provides increased or improved deformability or forming applicability. The inventors have determined that when the friction near or on the drawing radius is high, a greater force is required to pull the stock material above the drawing radius, which results in increased strain or elongation of the stock material and an increased risk of cracking or breaking of the resulting metal part. The inventors have found that reducing the friction near or on the drawing radius by the innovative member and the innovative position of said member means that less force is required to pull the blank above the drawing radius and excessive strain or elongation of the blank material is thus avoided. The result is an improved quality of the metal parts obtained.

Another advantage of the device according to the first aspect is that the coating on the mould is reduced, thereby reducing wear on the mould and reducing the amount of maintenance required, among other things. Due to the reduced cladding, the overall friction is also more stable, which results in improved tolerances of the resulting metal parts. As cladding occurs, the friction experienced by the blank changes, e.g., increases. When this occurs, the force required to form the resulting part from the blank may increase, which in turn may increase the risk of cracking and breaking the resulting metal part. The result is also excessive strain or elongation of the blank material, which negatively affects the tolerances of the resulting metal part, since the movement of the blank during hot press forming is not the same from one press to the next. Furthermore, the device according to the first aspect has the advantage that an improved surface quality is obtained. When cladding occurs, the result is often scratching of the blank by pulling it during hot press forming, which is a problem, particularly with the resulting metal part visible when installed.

Another advantage of the device according to the first aspect is that less lubricant is required, which results in a reduced cost and less pollution of the environment by the hot press forming, which in turn provides for hot press forming with less negative impact on the environment.

The inventors have found that the above-mentioned problems solved by the device according to the first aspect are most pronounced near or above the drawing radius, since the maximum transverse displacement of the blank takes place near or above the drawing radius.

According to an advantageous embodiment of the thermoforming device according to the first aspect, at least a portion of the member is positioned or located on the drawing radius. The positive technical effects associated with this embodiment are mentioned above.

According to an advantageous embodiment of the hot press forming device according to the first aspect, at least a part of the component surrounds the mould cavity or the mould protrusion. An advantage of this embodiment is that the coating on the mould is further reduced and the above-mentioned positive technical effects are further enhanced.

According to another advantageous embodiment of the hot press forming device according to the first aspect, at least a part of the component is positioned outside the mould cavity or the mould protrusion. An advantage of this embodiment is that the coating on the mould is further reduced and the above-mentioned positive technical effects are further enhanced.

According to another advantageous embodiment of the hot press forming device according to the first aspect, the component is provided as a coating applied to a mould having a drawing radius. An advantage of this embodiment is that the member is attached to the mould in an efficient manner, whereby the above-mentioned positive technical effect is further enhanced.

According to a further advantageous embodiment of the thermoforming device according to the first aspect, the component is provided as a liquid which is applied to a mold having a drawing radius and subsequently cured. An advantage of this embodiment is that the member is attached to the mould in an efficient manner, whereby the above-mentioned positive technical effect is further enhanced.

According to another advantageous embodiment of the thermoforming device according to the first aspect, the member comprises an adhesive tape having a first surface and a second surface, wherein the first surface of the adhesive tape forms the first press forming surface of the member and the second surface of the adhesive tape is provided with at least one adhesive substance, and wherein the second surface of the adhesive tape is attached to the mold having the stretching radius by means of the at least one adhesive substance. An advantage of this embodiment is that the member is attached to the mould in an efficient and uncomplicated manner, thereby further enhancing the positive technical effect described above.

According to an advantageous embodiment of the hot press forming device according to the first aspect, the die having the drawing radius is provided with at least one recess of the holding member. An advantage of this embodiment is that the member is attached to the mould in an efficient manner, whereby the above-mentioned positive technical effect is further enhanced.

According to another advantageous embodiment of the thermoforming device according to the first aspect, the member is elastic. An advantage of this embodiment is that the displacement of the blank during hot press forming, e.g. the lateral displacement of the blank, is further improved. An advantage of this embodiment is also that the above-mentioned positive technical effects are further enhanced.

According to another advantageous embodiment of the hot press forming device according to the first aspect, the first die has a drawing radius and the member is attached to the first die. The inventors have found that the above problems relating to the draw radius are particularly pronounced in the mold cavity. An advantage of this embodiment is that the lateral displacement of the blank during hot press forming is further improved. An advantage of this embodiment is also that the above-mentioned positive technical effects are further enhanced.

According to a further advantageous embodiment of the thermoforming device according to the first aspect, the member is a polymer member. An advantage of this embodiment is that the lateral displacement of the blank during hot press forming is further improved. An advantage of this embodiment is also that the above-mentioned positive technical effects are further enhanced.

According to a further advantageous embodiment of the thermoforming device according to the first aspect, the polymer member is made of an elastomer or a mixture of elastomers. An advantage of this embodiment is that the lateral displacement of the blank during hot press forming is further improved. An advantage of this embodiment is also that the above-mentioned positive technical effects are further enhanced.

According to an advantageous embodiment of the thermoforming device according to the first aspect, the polymer member is at least partially made of polyimide. An advantage of this embodiment is that the displacement of the blank during hot press forming is further improved. An advantage of this embodiment is also that the above-mentioned positive technical effects are further enhanced.

According to another advantageous embodiment of the hot press forming device according to the first aspect, one of the first and second dies is an upper die placed above the other die being a lower die, wherein at least one of the first and second dies is substantially vertically movable relative to the other die, and wherein the substantially vertically movable die is configured to be moved substantially vertically towards the other die for press forming the blank. An advantage of this embodiment is that the above-mentioned positive technical effects are further enhanced.

According to a second aspect of the present invention, the above and other objects of embodiments of the present invention are achieved by providing a method for hot press forming a blank, the method comprising the steps of:

placing the blank between a first mold and a second mold, wherein the first mold has at least one mold cavity and the second mold has at least one mold projection, the mold projection of the second mold being complementary to the mold cavity of the first mold, wherein at least one of the first mold and the second mold has a drawing radius, wherein the component is attached to the mold having the drawing radius on which at least a portion of the component is positioned adjacent to or on the drawing radius, wherein the component defines a first press forming surface and the mold holding the component defines a second press forming surface outside the first press forming surface;

heating the blank; and

the blank placed between the first and second dies is press formed by the first and second dies, wherein during the same hot press forming a first friction force occurs between the blank and the first press forming surface when the blank is in contact with the component and a second friction force occurs between the blank and the second press forming surface when the blank is in contact with the die holding the component, the first friction force being smaller than the second friction force.

The advantages of the method according to the second aspect of the invention correspond to the advantages described above in connection with the thermoforming apparatus according to the first aspect.

According to an advantageous embodiment of the method according to the second aspect, one of the first and second dies is an upper die placed above the other die being the lower die, and the method is characterized in that at least one of the first and second dies is moved substantially vertically towards the other die for press-forming the blank. An advantage of this embodiment is that the above-mentioned positive technical effects are further enhanced.

The above-described features and embodiments of the thermoforming apparatus and method, respectively, may be combined in various possible ways to provide further advantageous embodiments.

Further advantageous embodiments of the hot press forming device and method according to the invention and further advantages of the embodiments of the invention emerge from the dependent claims and the detailed description of the embodiments.

Drawings

Aspects of the invention will now be described in more detail, by way of example only, and with reference to the accompanying drawings, in which:

fig. 1 is a schematic side view of a first embodiment of a thermoforming device according to the first aspect;

FIG. 2 is a schematic top view of a first mold of the apparatus of FIG. 1;

fig. 3 is a schematic side view of a second embodiment of a thermoforming device according to the first aspect;

FIG. 4 is a schematic top view of a first mold of the apparatus of FIG. 3;

fig. 5 is a flow chart illustrating an embodiment of a method according to the second aspect of the present invention.

Detailed Description

Referring to fig. 1 and 2, a hot press forming apparatus 102 for forming a blank 104 is provided. The blank 104 may comprise or consist of a metal or metal alloy. The blank 104 may comprise or consist of aluminum or a metal alloy including aluminum. The blank 104 may be a sheet of material, for example a sheet comprising or consisting of a metal or metal alloy. The thermoforming device 102 includes a first mold 106 and a second mold 108. The first mold 106 has at least one mold cavity 110 surrounded by the remainder of the first mold 106. The second mold 108 has at least one mold projection 112. The mold projections 112 of the second mold 108 are complementary to the mold cavities 110 of the first mold 106. The first mold 106 may be referred to as a female mold and the second mold 108 may be referred to as a male mold. Each of the first mold 106 and the second mold 108 may comprise or consist of a metal or a metal alloy. In the embodiment shown in fig. 1 and 2, one of the first mold 106 and the second mold 108 is an upper mold 108 placed above the other mold 106, which is a lower mold 106. At least one of the first and second molds 106, 108 is substantially vertically movable relative to the other mold 106, 108 in a substantially vertical direction 114. The substantially vertically movable dies 106, 108 are configured to move substantially vertically towards the other die 106, 108 for press forming the blank 104. The first mold 106 may be a lower mold 106 or an upper mold relative to the second mold 108. The second mold 108 may be an upper mold 108 or a lower mold with respect to the first mold 106. In the embodiment shown in fig. 1 and 2, the first mold 106 is a lower mold 106 and the second mold 108 is an upper mold 108. However, other positions of the first and second molds 106, 108 are possible.

Referring to fig. 1 and 2, the hot press forming device 102 is configured to press-form the blank 104 placed between the first die 106 and the second die 108 by the first die 106 and the second die 108. At least one of the first die 106 and the second die 108 has a draw radius 116, or defines or exhibits a draw radius 116. In the embodiment shown in fig. 1 and 2, at least the first die 106 has a draw radius 116. The drawing radius 116 may be adjacent to the mold cavity 110 of the first mold 106. When the second mold 108 (i.e., the male mold) has a stretch radius, the stretch radius may be adjacent to the mold protrusion 112 of the second mold 108.

The apparatus 102 includes a member 118 attached to a mold 106 having a draw radius 116. The device 102 may include a plurality of members 118 attached to the mold 106. Thus, in the embodiment shown in fig. 1 and 2, the member 118 is attached to the first mold 106. At least a portion 119 of member 118 is positioned adjacent to or on stretch radius 116. The member 118 defines a first press forming surface 120. The die 106 of the retaining member 118 (in this case the first die 106) defines a second press forming surface 122 outside the first press forming surface 120. The area of the first press forming surface 120 may be less than 25% of the area of the second press forming surface 122, such as less than 10% of the area of the second press forming surface 122.

The member 118 and the die 106 holding the member 118 are configured such that during the same hot press forming a first friction force occurs or exists between the blank 104 and the first press forming surface 120 when the blank 104 is in contact with the member 118 and possibly moved relative to the member, and a second friction force occurs between the blank 104 and the second press forming surface 122 when the blank 104 is in contact with the die 106 holding the member 118 and possibly moved relative to the die. As described above, in the embodiment shown in fig. 1 and 2, the first die 106 retains the member 118. The first frictional force (i.e., the frictional force between the blank 104 and the first press forming surface 120) is less than the second frictional force (i.e., the frictional force between the blank 104 and the second press forming surface 122).

Frictional forces are forces that resist the relative motion of a solid surface, a fluid layer, and a material element sliding against each other. The dry friction force is a force that opposes the relative lateral movement of two solid surfaces in contact (i.e., the blank 104 and the first press forming surface 120, or the blank 104 and the second press forming surface 122, for the solution described in this disclosure). Dry friction can be subdivided into static friction between non-moving surfaces ("stiction") and dynamic friction between moving surfaces. The first friction force is reduced relative to the second friction force, i.e. the first friction force is smaller than the second friction force. The coefficient of friction COF of the first press forming surface 120 is less than the COF of the second press forming surface 122, which is effective for both static and dynamic/sliding friction. The first friction may be at least 10% lower, such as at least 30% lower, or at least 50% lower than the second friction. For example, the COF of the first press forming surface 120 may be at least 10% lower, such as at least 30% lower, or at least 50% lower than the COF of the second press forming surface 122. The member 130 may be referred to as a friction reducing member 130.

The member 118 is advantageously elongate. The material of the component 118 or the material of the first press forming surface 120 may be different from the material of the mold 106 holding the component 118 or different from the material of the second press forming surface 122. Each of the first press forming surface 120 and the second press forming surface 122 may be provided with a structure or pattern. The structure or pattern may comprise grooves and/or stripes. The structure or pattern of the first press forming surface 120 may be different from the structure or pattern of the second press forming surface 122. The member 118 may be adjacent to the mold cavity 110 of the first mold 106. If the second mold 108 holds a member, the member may be adjacent to the mold projection 112. Both the first die 106 and the second die 108 may hold their own member 118 or members 118. The member 118 may be a polymeric member 118. The polymer member 118 may be made of an elastomer or a mixture of elastomers. Advantageously, the polymer member 118 is at least partially made of polyimide. The entire member 118 may be made of polyimide.

Referring to fig. 2, at least a portion of the member 118 or the entire member 118 surrounds the mold cavity 110 of the first mold 106. If the second mold 108 holds the member 188, the member 118 may surround the mold protrusion 112 of the second mold 108. At least a portion of the member 118 is positioned outside of the mold cavity 110 of the first mold 106. If the second mold 108 holds the member 188, at least a portion of the member 118 may be positioned outside of the mold projections 112 of the second mold 108.

Referring to the first embodiment of fig. 1 and 2, the member 118 may be provided as a coating applied to a die 106 having a draw radius 116 (e.g., the first die 106). Alternatively, the member 118 may be provided as a liquid that is applied to the mold 106 having the stretch radius 116 and may subsequently be cured. Alternatively, the member 118 may comprise an adhesive tape having a first surface 120 and a second surface 124. The first surface 120 of the adhesive tape forms the first press forming surface 120 of the member 118 and the second surface 124 of the tape is provided with at least one adhesive substance. The second surface 124 of the tape is attached to the mold 106 having the stretch radius 116, i.e., the first mold 106 in the embodiment shown in fig. 1 and 2, by the at least one adhesive substance.

Referring to fig. 3 and 4, a second embodiment of the apparatus 202 is shown. In most cases, the device 202 of the second embodiment of fig. 3 and 4 corresponds to the device 102 of the first embodiment of fig. 1 and 2. Except that a mold 206 (e.g., a first mold 206 having a mold cavity 210) having a drawing radius 216 is provided with at least one depression 226 or groove to retain the member 218. At least a portion 219 of member 218 is positioned adjacent to or on stretch radius 216. The member 218 may substantially correspond to the member 118 of fig. 1 and 2. For example, the member 218 also defines a first press forming surface 220. However, the component 218 of fig. 3 and 4 is resilient or flexible such that prior to thermoforming, a first press forming surface 220 of the component 218 is slightly raised above a second press forming surface 222 of the first mold 206, the second press forming surface 222 being located outside the first press forming surface 220. When the blank 104 is pressed by the first die 206 and the second die 108, the resilient member 218 is compressed and the first press forming surface 220 of the member 218 is thus moved towards the same horizontal as the second press forming surface 222 of the first die 206. Apart from this, the features of the device 202 of the second embodiment of fig. 3 and 4 correspond to the features of the device 102 of the first embodiment of fig. 1 and 2 and are therefore not repeated here. For example, the second mold 108 of the second embodiment apparatus 202 of fig. 3 and 4 corresponds to the second mold 108 of the first embodiment apparatus of fig. 1 and 2.

Referring to fig. 5, a flow chart illustrates an embodiment of a method for hot briquetting the blank 104 according to the second aspect of the invention. The method comprises the following steps:

placing 301 the blank 104 between a first die 106 and a second die 108, wherein the first die 106 has at least one die cavity 110 and the second die 108 has at least one die projection 112, the die projection 112 of the second die 108 being complementary to the die cavity 110 of the first die 106, wherein at least one of the first die 106 and the second die 108 has a draw radius 116, wherein the member 118 is attached to the die 106 having the draw radius 116, at least a portion 119 of the member 118 being located adjacent to or on the draw radius 116, wherein the member 118 defines a first press forming surface 120 and the die 106 holding the member 118 defines a second press forming surface 122 outside the first press forming surface 120;

heating 302 the blank 104; and

the blank 104 placed between the first die 106 and the second die 108 is press formed 303 by the first die 106 and the second die 108, wherein during the same hot press forming a first friction force occurs between the blank 104 and the first press forming surface 120 when the blank 104 is in contact with the component 118 and possibly moved relative to said component, and a second friction force occurs between the blank 104 and the second press forming surface 122 when the blank 104 is in contact with the die 106 holding the component 118 and possibly moved relative to said die, the first friction force being smaller than the second friction force.

The step of press forming 303 may include: when one of the first die 106 and the second die 108 is an upper die 108 placed above the other die 106 as a lower die 106, at least one die 106, 108 of the first die 106 and the second die 108 is moved substantially vertically toward the other die 106, 108 for press forming the blank 104. The step of placing 301 the blank 104 between the first die 106 and the second die 108 may be performed by: the blank 104 is moved relative to the first die 106 and/or the second die 108, for example by lateral movement of the blank 104, or the first die 104 and/or the second die 106 is moved relative to the blank 104, for example by lateral movement of the first die 104 and/or the second die 106. The blank 104 may be heated 302 before placing the blank 104 between the first die 106 and the second die 108 or after placing the blank 104 between the first die 106 and the second die 108. However, the blank 104 is always heated before the press forming 303. After press forming 303, the step of cooling the blank 104 may be performed.

The features of the different embodiments of the apparatus and method disclosed above may be combined in various possible ways to provide further advantageous embodiments. The invention should not be regarded as being limited to the embodiments shown, but may be modified and varied in many ways by a person skilled in the art without departing from the scope of the appended claims.