DIFFERENT DIE BINDER PIN PATTERNS

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This PCT Patent Application claims the benefit of and priority to U.S.

Provisional Patent Application Serial No. 62/060,185 filed October 6, 2014, the entire disclosure of the application being considered part of the disclosure of this application, and hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0002] The invention relates generally to a press bolster adaptor, a stamping apparatus including the press bolster adaptor, and a method of manufacturing parts using the press bolster adaptor.

2. Related Art

[0003] A stamping apparatus is oftentimes used to shape metal parts, such as steel or aluminum parts for automotive vehicle applications. The stamping apparatus typically includes a ram, press, upper die and lower die for deep drawing or otherwise shaping the metal parts therebetween. Each die of the stamping apparatus presents a forming surface having a predetermined design, which depends on the design of the part being formed. The lower die includes a die binder to hold the blanks during the forming process. The die binder is designed to accommodate the size and shape of the blank, which varies depending on the part being formed.

[0004] The stamping apparatus also includes a plurality of pins, referred to as cushion pins, disposed between a press bolster and the die binder. During the stamping process, the cushion pins are driven to engage and move the die binder vertically relative to the forming surface and thus locate the blank in a desired position. The pins are received in a pattern of holes of the press bolster, which is preferably designed such that the pins engage specific locations of the associated die binder. It is important that the cushion pins engage the die binder in the correct locations, in order to achieve a robust stamping process and avoid damage to the part being formed or the dies.

[0005] Such stamping apparatuses can be designed large enough to form Class A automotive parts, such as side panels, hoods, roofs, and wheel housings. For example, a die having a cross-sectional area of about 7 feet by 15 feet, or greater, is commonly used to form the Class A automotive parts. However, this type of apparatus is costly to manufacture and maintain, due to its large size. Thus, manufacturers of the Class A automotive parts typically own a single large stamping apparatus. In order to form parts of various different designs, they can switch the dies to obtain the desired forming surface.

[0006] However, a common problem encountered by the manufactures is that the pin pattern of the press bolster does not match the pin partem required by the new die binder, and thus the cushion pins received in the press bolster do not engage the binder in the correction locations. In this case, the desired die cannot be used, as the cushion pins could damage the die or the parts being formed. This problem often occurs when the manufacturer attempts to use a die made in a different geographical region, due to different units of measurement (for example, imperial versus metric) and different requirements.

SUMMARY OF THE INVENTION

[0007] The invention provides a press bolster adaptor for a stamping apparatus designed to accommodate various different die binders. Thus, a single press bolster can be used with various different dies, which reduces manufacturing costs, especially when the stamping apparatus is designed to form large Class A automotive parts. [0008] The bolster adaptor comprises a base plate including a plurality of side walls, a top plate extending perpendicular to and disposed on the side walls, and a float plate extending parallel to the top plate and surrounded by the side walls of the base plate. The top plate includes a plurality of pin holes. Lower cushion pins are disposed below the float plate, and upper cushion pins are disposed on the float plate. The upper cushion pins extend through the pin holes of the top plate to engage a die binder.

[0009] During the stamping process, the lower cushion pins are pressed into the float plate and move the float plate, as well as the upper cushion pins supported by the float plate, toward the die binder. The upper cushion pins travel through the pin holes of the top plate and engage the die binder in appropriate locations. Thus, the dies can form the part to a desired shape in a robust manner, without damage to the part being formed or the dies.

[0010] In addition, the upper cushion pins can be rearranged to accommodate new die binders having different designs. Alternatively, if the pin partem of the top plate is not suitable for a specific die binder, the top plate can be replaced for one having a different pin pattern. Due to the bolster adaptor, the same press bolster can be used with many different die binders and their many different pin patterns. As a result, the bolster adaptor reduces manufacturing costs without impacting the quality of the stamping process or parts formed by the stamping process.

[0011] The invention also provides a stamping apparatus including a press bolster adaptor. The stamping apparatus further includes an upper die and a lower die each presenting a forming surface for forming parts therebetween. The lower die includes a die binder, and a press bolster is located beneath the lower die. The press bolster includes a base surface facing the lower die, and a plurality of lower cushion pins are disposed on the base surface of the press bolster. The press bolster adaptor is disposed between the press bolster and the die binder of the lower die. [0012] A method of manufacturing parts using a stamping apparatus with a press bolster adaptor is also provided. The method includes disposing the press bolster adaptor between a press bolster and a first die binder of a lower die. The press bolster comprises a base plate including a plurality of side walls, a top plate extending perpendicular to and disposed on the side walls, and a float plate extending parallel to the top plate and surrounded by the side walls of the base plate. A plurality of lower cushion pins are disposed below the float plate. The top plate includes a plurality of pin holes, and a plurality of upper cushion pins are disposed on the float plate in a first partem. The upper cushion pins also extend through the pin holes of the top plate. The method further includes forming a plurality of first parts between an upper die and the lower die. The step of forming the first parts includes driving the lower cushion pins into the float plate to drive the upper cushion pins through the pin holes of the top plate and into engagement with the first die binder.

[0013] In one embodiment, the method includes replacing the first die binder with a second die binder, wherein the shape of the second die binder is different from the shape of the first die binder; rearranging the upper cushion pins on the float plate in a second pattern, wherein the second pattern is different from the first pattern; and forming a plurality of second parts between the upper die and the lower die. The step of forming the second parts includes driving the lower cushion pins into the float plate to drive the upper cushion pins through the pin holes of the top plate and into engagement with the second die binder. Alternatively, the method can include replacing a first top plate having a first pin partem to match the first die binder with a second top plate having a second pin pattern to match the second die binder, wherein the second pin partem is different from the first pin pattern; and rearranging the upper cushion pins on the float plate and through the pin holes of the second top plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

[0015] Figure 1 illustrates an exemplary stamping apparatus including a press bolster adaptor in a closed position;

[0016] Figure 2 illustrates the stamping apparatus of Figure 1 in an open position;

[0017] Figures 3 and 4 are exploded views of the stamping apparatus of Figure 1 showing a plurality of upper cushion pins disposed between the bolster adaptor and a lower die and a plurality of lower cushion pins disposed between the bolster adaptor and a press bolster;

[0018] Figure 5 is a top view of a press bolster showing an exemplary pin opening pattern;

[0019] Figures 6 and 7 are top views of a top plate of the press bolster adaptor including pin opening patterns according to exemplary embodiments;

[0020] Figure 8 is a bottom view of an exemplary die binder, wherein specific locations to be engaged by cushion pins are identified;

[0021] Figures 9-12 illustrate the press bolster adaptor with the top plate removed to show support bars disposed in numerous locations according to an exemplary embodiment; and

[0022] Figures 13 and 14 are perspective view of a float plate according to an exemplary embodiment.

DETAILED DESCRIPTION

[0023] The invention provides a stamping apparatus 20 including a bolster adaptor

22 for deep drawing or otherwise forming parts 24, such as large Class A automotive parts 24 formed of steel or aluminum. The bolster adaptor 22 includes a pin partem which can be designed to accommodate a variety of different die binders 26, and thus a variety of different dies can be used with a single press bolster and its associated fixed pin pattern. For example, a single press bolster can be used with dies built in geometric regions using imperial units, as well as with dies built in geometric regions using metric units. Due to the bolster adaptor 22, it is no longer required to obtain a press bolster with a pin partem designed specifically for each new die. Thus, manufacturing costs are reduced, especially when manufacturing the large Class A automotive parts 24, without impacting the quality of the stamping process or stamped part 24.

[0024] Figures 1-4 illustrate the stamping apparatus 20 including the bolster adaptor

22 according to an exemplary embodiment. The stamping apparatus 20 includes a ram 28 coupled to an upper die 30, and a press bolster 32 located below a lower die 34. The lower die includes the die binder 26 for holding a metal blank to be formed. Each die 30, 34 presents a forming surface 36 having a design which depends on the part 24 being formed. During the stamping process, a metal blank is placed between the forming surfaces 36 of the dies 30, 34, and the ram 28 moves the upper die 30 toward the lower die 34. The metal blank is then formed to a predetermined shape which depends on the forming surfaces 36 of the opposing dies 30, 34. In the exemplary embodiment, the forming step includes deep drawing the metal blank to form the shaped part 24. Figure 1 shows the stamping apparatus 20 in a closed position, and Figure 2 shows the stamping apparatus 20 in an open position.

[0025] The press bolster 32 of the stamping apparatus 20 includes a base surface 38 facing the lower die 34 and including a plurality of pin openings 40 disposed in a fixed pattern for receiving a plurality of lower cushion pins 42. The pattern of the pin openings 40 typically varies from one press bolster 32 to another. For example, the partem of the pin openings 40 can vary depending on the geographical region in which the press bolster 32 is manufactured. Figures 3 and 4 show the lower cushion pins 42 disposed in the pin openings 40 of the press bolster 32 according to an exemplary embodiment. A top view of the exemplary press bolster 32 is shown in Figure 5.

[0026] As shown in Figures 1 and 2, the bolster adaptor 22 is placed between the press bolster 32 and the lower die 34. The bolster adaptor 22 includes a base plate 44 surrounding the lower cushion pins 42, and a top plate 46 disposed on the base plate 44 and spaced from a top end of the lower cushion pins 42. A float plate 48 is disposed within the base plate 44 for moving toward and away from the top plate 46 during the stamping process. A plurality of upper cushion pins 50 rest on the float plate 48, and the top plate 46 includes a plurality of pin holes 52 for receiving the upper cushion pins 50. The upper cushion pins 50 are arranged in a pattern to engage the die binder 26 at the correct locations. Thus, the pattern of the upper cushion pins 50 varies depending on the specific die binder 26 being used. However, the same press bolster 32 with the fixed pin partem can be used with the various different die binders 26.

[0027] The pattern of the pin holes 52 in the top plate 46 is also designed so that the upper cushion pins 50 received in the pin holes 52 can engage the die binder 26 at the correct locations. In one embodiment, there are numerous pin holes 52 so that the upper cushion pins 50 can be disposed in a plurality of different patterns, removed from the pin holes 52, and rearranged in the pin holes 52 to accommodate different die binders 26. In another embodiment, the pin holes 52 of the top plate 46 are disposed in a specific pattern designed to accommodate the specific die binder 26 being used. Thus, when a manufacturer switches to a new die binder 26 requiring a different pin partem, the existing top plate 46 is removed from the base plate 44 of the bolster adaptor 22 and replaced with a new top plate 46 having a different pin pattern. Figures 6 and 7 show exemplary top plates 46 having pin patterns designed to accommodate various different die binders 26. Figure 8 is a bottom view of an exemplary die binder 26, wherein specific locations contacted by the upper cushion pins 50 are identified at 54.

[0028] Rearranging the upper cushion pins 50 in the pin holes 52 of the top plate 46 or obtaining a new top plate 46 with the desired pin pattern is typically less expensive and more convenient than obtaining a new press bolster 32 with the desired pin partem, due to the large size and cost of the press bolster 32. The top plate 46 can be easily removed from the side walls 58 of the base plate 44 because the thickness and weight of the top plate 46 is less than the thickness and weight of the press bolster 32, and the length and width of the top plate 46 is not greater than the length and width of the press bolster 32.

[0029] The top plate 46 includes outer edges 56 which are support by side walls 58 of the base plate 44. However, as mentioned above, the top plate 46 is typically large, especially when the stamping apparatus 20 is designed to form large Class A parts 24, and thus additional support in the center of the top plate 46 is typically needed. In the exemplary embodiment, support bars 60 are attached to a lower surface 62 of the top plate 46 in order to support the center of the top plate 46. The support bars 60 rest on the base surface 38 of the press bolster 32 and prevent the top plate 46 from deforming during the stamping process. The support bars 60 can be disposed in various different locations, depending on where the support is needed. Figures 9-12 illustrate the bolster adaptor 22 with the top plate 46 removed to show the support bars 60 disposed in numerous locations along the base surface 38 of the press bolster 32. In addition to supporting the top plate 46, the support bars 60 also guide movement of the float plate 48 toward and away from the lower die 34 during the stamping process.

[0030] In the exemplary embodiment, the bolster adaptor 22 also includes a plurality of wear plates 64 disposed along an inner surface 66 of the side walls 58. The wear plates 64 are disposed parallel to the inner surface 66 of the side walls 58 and perpendicular to the base surface 38 of the press bolster 32. During the stamping process, the float plate 48 engages the wear plates 64, rather than the side walls 58, as it moves toward and away from the top plate 46. As the wear plates 64 are worn down, they can be conveniently replaced at a much lower cost than replacing the entire base plate 44.

[0031] The float plate 48 is surrounded by the side walls 58 of the base plate 44 and includes a plurality of cut-outs 68 allowing the support bars 60 to extend therethrough. Figures 13 and 14 illustrate the float plate 48 of an exemplary embodiment. During the stamping process, the lower cushion pins 42 move the float plate 48 along the wear plates 64 and support bars 60, toward and away from the top plate 46. Various different methods can be used to drive the lower cushion pins 42 toward the float plate 48. However, in the exemplary embodiment, a nitrogen-filled cylinder (not shown) is used. The nitrogen-filled cylinder is disposed beneath the press bolster 32 and lower cushion pins 42 and drives the lower cushion pins 42 upwards into the float plate 48. The lower cushion pins 42 lift the float plate 48, as well as the upper cushion pins 50 resting on the float plate 48, upward and toward the die binder 26. This step transfers force from the lower cushion pins 42 to the upper cushion pins 50. The upper cushion pins 50 travel through the pin holes 52 of the top plate 46 and engage the die binder 26 in the correct locations. The upper cushion pins 50 also move the die binder 26 upward toward the forming surfaces 36. The die binder 26 and forming surfaces 36 of the dies 30, 34 can thereby shape the part 24 into the desired shape. After the part 24 is formed into the desired shape, the die binder 26, float plate 48 and cushion pins 42, 50 move downward, back to their original position. This process is typically repeated numerous times in order to shape numerous parts 24. In the exemplary process, the stamping process includes deep drawing the metal blank, but other forming techniques can be used with the stamping apparatus 20 and bolster adaptor 22. [0032] As discussed above, the bolster adaptor 22 allows parts 24 to be formed using various different die binders 26 with the same press bolster 32. For example, the process can include forming first parts 24 using a first die binder 26; replacing the first die binder 26 with a second die binder 26, wherein the shape of the second die binder 26 is different from the shape of the first die binder 26; rearranging the upper cushion pins 50 on the float plate 48 in a second partem to match the second die binder 26, wherein the second pattern is different from the first pattern; and forming a plurality of second parts 24 using the second die binder 26. Alternatively, the method can include replacing a first top plate 46 having a pin partem designed for the first die binder 26 with a second top plate 46 having a pin pattern designed for the second die binder 26.

[0033] The invention also provides a method of manufacturing the stamping apparatus 20 including the bolster adaptor 22. The method includes disposing the base plate 44 of the bolster adaptor 22 on the press bolster 32, and disposing the lower cushion pins 42 in the pin openings 40 of the press bolster 32. The method then includes disposing the float plate 48 within the base plate 44, such that the float plate 48 rests on the lower cushion pins 42. The method further includes attaching the support bars 60 to the top plate 46 of the bolster adaptor 22, and disposing the top plate 46 on the side walls 58 of the base plate 44 such that the support bars 60 extend through the cut-outs 68 of the float plate 48 and rest on the base surface 38 of the press bolster 32. The method next includes inserting the upper cushion pins 50 through the pin holes 52 of the top plate 46. The desired dies 30, 34 are then disposed above the press bolster 32, bolster adaptor 22, and cushion pins 42, 50 to provide the finished stamping apparatus 20.

[0034] Obviously, many modifications and variations of the present invention are possible in light of the above teachings and may be practiced otherwise than as specifically described with within the scope of the following claims.