Abstract
A hot stamp tool including an annealing die and a hot forming die. A blank is placed in the hot forming die with a first transfer arm where it is formed and quenched into a shaped part. The shaped part is then moved from the hot forming die to the annealing die with a second transfer arm. In the annealing die, the shaped part continues to be cooled. The annealing die includes a heating element that heats a portion of the shaped part to the point of annealing to form an annealed part. The annealed part includes a non-annealed portion and an annealed portion with a transition zone between the annealed portion and the non-annealed portion. The annealed portion can then be deformed.
Claims
1. A hot stamp tooling assembly comprising: at least one hot forming die and at least one annealing die; the at least one hot forming die including an upper forming die and a lower forming die for shaping a blank into a shaped part; the at least one annealing die including an upper annealing die and a lower annealing die for receiving the shaped part; the at least one annealing die including at least one cooling element and at least one heating element, the cooling element located adjacent to the heating element; and wherein the at least one heating element anneals a portion of the shaped blank and the at least one cooling element simultaneously cools a portion of the shaped blank adjacent to the at least one heating element to hinder heat transfer from the at least one heating element to the cooled portion.
2. The hot stamp tooling assembly of claim 1, wherein the at least one heating element includes an upper induction coil located in the upper annealing die and a lower induction coil located in the lower annealing die.
3. The hot stamp tooling assembly of claim 2, wherein the at least one cooling element includes upper die channels located in the upper annealing die adjacent to the upper induction coil and a lower die channel located in the lower annealing die adjacent to the induction coil, wherein the upper die channels and the lower die channels transfer a coolant adjacent to the induction coils.
4. The hot stamp tooling assembly of claim 1, further including a first transfer arm for placing at least one blank into the at least one hot forming die and a second transfer arm for removing the at least one blank once it has been shaped into a shaped part and placing the shaped part into the at least one annealing die.
5. The hot stamp tooling assembly of claim 4, wherein the at least one hot forming die includes a first hot forming die and a second hot forming die and wherein the at least one annealing die includes a first annealing die and a second annealing die.
6. The hot stamp tooling assembly of claim 5, wherein the first transfer arm includes a first blank holder and a second blank holder for simultaneously placing a first blank into the first hot forming die and a second blank into the second hot forming die.
7. The hot stamp tooling assembly of claim 6, wherein the second transfer arm includes a first shaped part holder and a second shaped part holder for removing the shaped part from the first hot forming die and the second hot forming die and placing them in the first annealing die and the second annealing die, and wherein the second transfer arm includes a third holder and a fourth holder for removing a part from the first annealed die and the second annealed die simultaneously with the removal of the shaped part from the first hot forming die and the second hot forming die.
8. The hot stamp tooling assembly of claim 7, wherein the first hot forming die and the second hot forming die are spaced apart by the first annealing die and wherein the first annealing die and the second annealing die are spaced by the second hot forming die.
9. The hot stamp tooling assembly of claim 1, further including a control system comprising: a processor; a memory that includes instructions that, when executed by the processor, cause the processor to: heat, with the at least one heating element, at least one portion of the shaped part above a recrystallization temperature; and cool, with the at least one cooling element, at least one portion of the shaped part adjacent to the at least one heated portion.
10. The hot stamp tooling assembly of claim 9, wherein the processor is further caused to cool, with the at least one cooling element, the at least one portion of the shaped part adjacent to the at least one heated portion to a temperature between 0° C. and 150° C.
11. The hot stamp tooling assembly of claim 9, wherein the at least one hot forming die includes upper cooling channels in the upper forming die and lower cooling channels in the lower forming die.
12. The hot stamp tooling assembly of claim 11, wherein the processor is further caused to cool, with the upper cooling channels and the lower cooling channels, the shaped part to slow heat transfer from the at least one heating element to surrounding portions of the shaped part.
13. A method of forming a part with tailored temper properties and transition zones comprising the steps of: hot forming a blank in a hot forming die until it is a shaped part; placing the shaped part in an annealing die and partially cooling and partially heating the shaped part in adjacent locations simultaneously to form at least one annealed portion and at least one non-annealed portions with a transition zone therebetween; and deforming the annealed portion.
14. The method of claim 13, wherein the transition zone is less than 20 mm.
15. The method of claim 13, further including partially cooling to a temperature between 0° C. and 150° C. and partially heating to a temperature at or above a recrystallization temperature.
16. The method of claim 13, wherein the shaped part is a B-pillar.
17. A method of forming a part comprising the steps of: providing a hot stamping tool having an annealing die and a hot forming die, wherein the annealing die includes a first shaped part and the hot forming die includes a first blank, shaping the first blank in the hot forming die during a first stroke to form a second shaped part, simultaneously cooling and annealing the first shaped part during the first stroke to form an annealed part, moving the annealed part away from the hot stamping tool and moving the second shaped part to the annealing die, and moving a second blank into the hot forming die after moving the second shaped part to the annealing die.
18. The method of claim 17, wherein a second transfer arm moves the annealed part away from the hot stamping tool and moves the second shaped part to the annealing die, and a first transfer arm moves the second blank into the hot forming die after the second transfer arm moves the second shaped part to the annealing die.
19. The method of claim 17 including heating the first blank and the second blank before the shaping step.
20. The method of claim 17, wherein the first shaped part is partially cooled and partially heated simultaneous and in adjacent locations in the annealing die to form the annealed part, the annealed part includes annealed portions and non-annealed portions, and the annealed part is a B-pillar.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The drawings described herein are for illustrative purposes only of selected embodiments and are not intended to limit the scope of the present disclosure. The inventive concepts associated with the present disclosure will be more readily understood by reference to the following description in combination with the accompanying drawings wherein:
[0012] FIG. 1 is a top view of a hot stamp tool assembly having a first transfer arm for placing parts into the hot stamp tool and a second transfer arm for removing parts from the hot stamp tool;
[0013] FIG. 2 is a cross-sectional side view of a hot forming die located within the hot stamp tool assembly;
[0014] FIG. 3A is a cross-sectional side view of an annealing die located within the hot stamp tool assembly;
[0015] FIG. 3B is an enlarged cross-sectional side view of the annealing die presented in FIG. 3A;
[0016] FIG. 4 generally illustrates a block diagram of a controlling system of the hot stamp tool assembly;
[0017] FIG. 5 is a series of top views of the hot stamp tool illustrating a process of forming a part with tailored temper properties with small transition zones;
[0018] FIG. 6A is an enlarged top view of the hot stamp tool assembly in a first step of the process shown in FIG. 4;
[0019] FIG. 6B is an enlarged top view of the hot stamp tool assembly in a second step of the process shown in FIG. 4;
[0020] FIG. 6C is an enlarged top view of the hot stamp tool assembly in a third step of the process shown in FIG. 4;
[0021] FIG. 6D is an enlarged top view of the hot stamp tool assembly in a fourth step of the process shown in FIG. 4;
[0022] FIG. 6E is an enlarged top view of the hot stamp tool assembly in a fifth step of the process shown in FIG. 4;
[0023] FIG. 6F is an enlarged top view of the hot stamp tool assembly in a sixth step of the process shown in FIG. 4;
[0024] FIG. 7 is a series of cross-sectional views of a part undergoing the process of forming tailored temper properties with small transition zones;
[0025] FIG. 8 is a top view of a part with tailored temper properties and small transition zones; and
[0026] FIG. 9 is a flow chart of a method for forming a part with tailored temper properties.
DESCRIPTION OF THE ENABLING EMBODIMENT
[0027] Example embodiments will now be described more fully with reference to the accompanying drawings. In general, the subject embodiments are directed to a hot stamp tool assembly and a method of forming a part with tailored temper properties. However, the example embodiments are only provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
[0028] Referring to the Figures, wherein like numerals indicate corresponding parts throughout the views, the hot stamp tool assembly and method of same ultimately provide a part with temper locations and non-temper locations and small transition zones between temper locations and non-temper locations.
[0029] Referring initially to FIG. 1, the hot stamp tool assembly 20 is generally shown. The hot stamp tool assembly 20 may include at least one hot forming die 22 (see FIG. 2) and at least one annealing die 24 (FIG. 3A). In some embodiments, the hot stamp tool assembly 20 includes a plurality of annealing dies 24, for example, a first annealing die and second annealing die 24 and a plurality of hot forming dies 22, for example, a first hot forming die and a second hot forming die 22. A first transfer arm 26 is located on one side of the hot stamp tool assembly 20 and a second transfer arm 28 is located on an opposite side of the hot stamp tool assembly 20. The first transfer arm 26 includes at least one blank holder 30, such as a hydraulically operated clamp, an energized magnet, a suction device, or any other implements conventionally utilized for moving blanks between locations. In some embodiments, the at least one blank holder 30 may include a first blank holder and a second blank holder 30. The second transfer arm 28 includes at least one shaped part holder 32, such as a hydraulically operated clamp, an energized magnet, a suction device, or any other implements conventionally utilized for moving shaped blanks between locations. In some embodiments, the at least one shaped part holder 32 may include a first shaped part holder, a second first shaped part holder, a third shaped part holder, and a fourth shaped part holder 32.
[0030] As illustrated by the arrows, the first transfer arm 26 connects to a pair of heated blanks 34A and removes them from a furnace 25 with a respective one of the first blank holders 30 and simultaneously places one heated blank 34A in the first hot forming die 22 and the other heated blank 34A in the second hot forming die 22. Once the heated blanks 34A have been placed into the hot forming dies 22, a stroke of the hot forming dies 22 stamps each of the blanks 34A into a shaped part 34B. While located in the hot forming dies 22, the blanks may also be quenched. The combination of heating and rapidly cooling may change a microstructure of at least a portion of the shaped parts 34B. For example, the heating and quenching may result in the formation of martensitic in at least a portion of the shaped parts 34B. After shaped and quenched, the second transfer arm 28 removes the shaped parts 34B with two of the shaped part holders 32 and places one shaped part 34B in the first annealing die 24 and the other shaped part 34B in the second annealing die 24. The shaped parts 34B then undergo an annealing process. For example, portions of the shaped parts 34 may be reheated to above a recrystallization temperature and then slowly cooled until they are annealed, thus becoming annealed parts 34C. While the shaped part 34B is located in the annealing die 24, it may further be subjected to additional cooling on portions of the shaped part 34B adjacent to those portions of the shaped part 34B that are annealed. The second transfer arm 28 removes the annealed parts 34C with two of the other shaped part holders 32 that were not used in placing the shaped parts 34B into the annealing die 24. In operation, the second transfer arm 28 may thus simultaneously connect to two or more shaped parts 34B and two or more annealed parts 34C with each of the shaped part holders 32 and move the shaped parts 34B between the forming dies 22 and the annealing dies 24 while removing the annealed parts 34C from the annealing dies 24 in one process step.
[0031] FIG. 2 is a cross-sectional side view of one of the hot forming dies 22 located within the hot stamp tool assembly 20. Each of the hot forming dies 22 may include the same configuration and operational parameters. The hot forming die 22 includes a upper forming die 36 and a lower forming die 38 defining a forming cavity 40 therebetween. Inner surfaces of the upper forming die 36 and the lower forming die 38 may include topographical features to form the shaped part 34B into any number of shapes, including automotive components such as automotive pillars. The upper forming die 36 includes a series of upper forming die channels 42 located adjacent to the forming cavity 40 and the lower forming die 38 includes a series of lower forming die channels 44 located adjacent to the forming cavity 40. The upper forming die channels 42 and the lower forming die channels 44 thus provide quenching of the shaped part 34B with liquid coolant that is circulated therein or static cooling devices that are located therein. In some embodiments, the quenching process in the hot forming dies 22 may thus circulate coolant and change the microstructure in at least a portion of the shaped part 34B (e.g., forming martensite). In some embodiments, the shaped part 34B is cooled at a rate of at least 27° C. per second and martensite may be formed between 200° C. and 400° C. The upper forming die 36 and the lower forming die 38 may define a bend portion 46 of the cavity 40 that forms a stiffener flange 35 in the shaped part 34B. Cooling channels 42, 44 may be located adjacent to the entire outline wherein the shaped part 34B will be located, including the bend portion 46 such that primarily the entire shaped part is quenched. In some embodiments, the coolant in the forming die 22 may include a liquid, such as water, circulated at a temperature between 7° C. and 38° C.
[0032] FIGS. 3A and 3B are cross-sectional side views of the annealing die 24 located within the hot stamp tool assembly 20. Each of the annealing dies 24 may include the same configuration and operational parameters. The annealing die 24 includes an upper annealing die 48 and an lower annealing die 50 defining an annealing cavity 52 therebetween. Inner surfaces of the upper annealing die 48 and an lower annealing die may include topographical features similar to that of the hot forming dies 22. The upper annealing die 48 includes a series of upper die channels 54 located adjacent to the annealing cavity 52 and the lower annealing die 50 includes a series of lower die channels 56 located adjacent to the annealing cavity 52. The upper die channels 54 and the lower die channels 56 may provide continued cooling of the shaped part 34B with coolant that is circulated therein or static cooling materials that are located therein. The cooling operation in the annealing die 24 may cause further reduce the temperature of portions of the shaped part 34B to between 0° C. and 150° C. In some embodiments, the coolant in the annealing die 24 may include a liquid, such as water, circulated at a temperature between 20° C. and 35° C. In some embodiments, the shaped part 34B is placed in the annealing die 24 once it reaches a temperature below 200° C.
[0033] The upper annealing die 48 may include at least one upper heating element, such as an upper induction coil 58 located adjacent to the annealing cavity 52 and the lower annealing die 50 may include at least one lower heating element, such as a lower induction coil 60, located adjacent to the annealing cavity 52. The at least one lower induction coil 58 may be disposed adjacent to and on an opposite side of the cavity 52 from the at least one upper induction coil 60. In some embodiments, the upper annealing die 48 includes two upper induction coils 58 located in a spaced relationship, wherein the series of upper die channels 54 are located between each of the upper induction coils 48. Similarly, the lower annealing die 50 may include two lower induction coils 60 located in a spaced relationship, wherein the series of lower die channels 56 are located between each of the lower induction coils 60. In some embodiments, the die channels 54, 56 are located on either side of the induction coils 58, 60. In some embodiments, the induction coils 58, 60 are located at a trim location of the shaped part 34B. In operation, the induction coils 58, 60 may rapidly heat and anneal the shaped part 34B at the trim location while the cooling channels 54, 56 maintain a lower temperature on locations of the shaped part 34B adjacent to the induction coils 58, 60, thus decreasing the creeping effect of the heat transfer and a reducing the size of a transition zone between the annealed portions of the shaped part 34B and the non-annealed portions of the shaped portion 34B.
[0034] As best illustrated in FIG. 3B, the annealing die 24 may include a annealing die insert that includes an upper annealing die insert 62 and a lower annealing die insert 64 that can be moved independently of the upper annealing die 48 and the lower annealing die 50. The upper and lower annealing die inserts 62, 64 define an annealing insert cavity 66 with a bend 68 that accommodates the stiffener flange 35. Both annealing inserts 62, 64 are located on an outside portion of annealing die 24 from the induction coils 58, 60. As such, the quenched area is spaced from the stiffener flange 35 by a portion of the annealed part 34C which has been softened through annealing. The stiffener flange 35 can later be removed via cutting. No cooling channels may be necessary next to the stiffener flange 35 if it will be removed. However, the die channels 54, 56 opposite the stiffener flange 35 hinder the transition zone from creeping into portions other than the annealed portion and the stiffener flange 35. The stiffener flange 35 also prevents distortion of the annealed part 34C during the annealing process. However, in some embodiments it should be appreciated that the die channels 54, 56 may be located on opposite sides of the induction coils 58, 60. For example, it may be beneficial to allow the stiffener flange 35 to be quenched such that a trimming operation on the annealed portion is modified. In some embodiments, the trim portion and/or trimming operation may include deforming, piercing, cutting, etc. without departure from the subject disclosure. As such, when the die channels 54, 56 are located on opposite sides of the induction coils 58, 60, the annealed portion may be completely surrounded by the quenched portions. In some embodiments, the trim portion is inset from but outlines an entire or partial periphery of the annealed part 34C. In some embodiments, the upper and lower annealing die inserts 62, 64 may perform the trimming operation.
[0035] FIG. 4 generally illustrates the control system 80 according to the principles of the present disclosure. The control system 80 may include a controller 82 and the controller 82 may include a processor 84 and a memory 86. The processor 84 may include any suitable processor, such as those described herein. Additionally, or alternatively, the controller 82 may include any suitable number of processors, in addition to or other than the processor 84. The memory 86 may comprise a single disk or a plurality of disks (e.g., hard drives), and includes a storage management module that manages one or more partitions within the memory 86. In some embodiments, memory 86 may include flash memory, semiconductor (solid state) memory or the like. The memory 86 may include Random Access Memory (RAM), a Read-Only Memory (ROM), or a combination thereof. The memory 86 may include instructions that, when executed by the processor 84, cause the processor 84 to, at least, perform the systems and methods described herein. The controller 82 may control operations of the forming die 22, the annealing die 24, the first transfer arm 26, the second transfer arm 28, and other features.
[0036] FIG. 5 is a series of top views of the hot stamp tool illustrating sequential steps of a process 100 of forming tailored temper properties in a part with small transition zones. Each step in the process 100 may be carried out by instructions from the memory executed by the processor. Each of the hot stamp tools illustrated in FIG. 5 is the same hot stamp tool as a function of time during the course of process 100. The process 100 begins with providing 102 a hot stamp tool having a pair of annealing dies and a pair of hot forming dies, wherein the hot forming dies each include a blank and the annealing dies each include a shaped part (which was previously a blank formed in one of the hot forming dies). During a stroke 104 of the hot stamp tool, the hot forming dies shape 106 the blanks into a shaped part and may further include a quenching 108 step, such as by a series of cooling channels, wherein a hardened microstructure may be formed within the shaped part. During the stroke 104, the annealing die simultaneously cools 110 and anneals 112 adjacent locations on the shaped part to form an annealed part. The step of annealing may include heating with an induction coil and the step of cooling may including cooling channels located adjacent to the induction coil. Next, the second transfer arm grabs 114 each of the shaped parts and each of the annealed parts and moves 116 the shaped parts to the annealing dies and moves 118 the annealed parts away from the hot stamp assembly. Once the shaped parts are moved 116, the first transfer arm moves 120 additional heated blanks into the hot forming dies. The heated blanks may be moved directly from a furnace. Next, the second transfer arm moves 122 the annealed parts into an area for additional processing (such as material deformation, trimming, piercing, or material removal of the annealed portion) and returns 124 into a position for step 114, wherein the process 100 repeats.
[0037] FIGS. 6A through 6F show enlarged steps 102 through 120 of the process 100. More particularly, FIG. 6A illustrates providing 102 a hot stamp tool having a pair of annealing dies and a pair of hot forming dies, wherein the hot forming dies each include a blank and the annealing dies each include a shaped part (which was previously a blank formed in one of the hot forming dies). FIG. 6B illustrates the second transfer arm grabbing 114 each of the shaped parts and each of the annealed parts and moving 116 the shaped parts to the annealing dies and moving 118 the annealed parts away from the hot stamp assembly. FIG. 6C illustrates the first transfer arm moving 120 additional heated blanks towards the hot forming dies from a furnace and the second arm moving the annealed parts away from the hot stamp assembly. FIG. 6D illustrates the first transfer arm moving 120 the additional heated blanks into the hot forming dies. FIG. 6E illustrates the second transfer arm moving 122 the annealed parts into an area for additional processing. FIG. 6F illustrates the second transfer arm returning 124 into a position for step 114, wherein the process 100 repeats.
[0038] FIG. 7 illustrates a series of cross-sectional views of a part undergoing a process 200 of forming tailored temper properties with small transition zones. Each step in the process 200 may be carried out by instructions from the memory executed by the processor. The process 200 presented in FIG. 7 may be included with non-overlapping steps in process 100, for example, between steps 102 through 112. More particularly, the process begins by providing 202 a heated blank directly from a furnace. The heated blank is then placed 204 within a hot forming die, wherein it is shaped 206 and quenched 208 via cooling channels to from a shaped part with a hardened microstructure, e.g., higher levels of martensite. Next, the shaped part is placed 210 within an annealing die, wherein it continues to be cooled 212 via die channels and locally annealed 214 with induction coils that are adjacent to the die channels. The step of cooling may include cooling portions of the shaped part adjacent to the induction coils to a temperature between 0° C. and 150° C. The portion of the shaped part that is cooled is entirely within the space between adjacent pairs of induction coils presented in FIG. 3A and FIG. 3B. The local annealing 214 step may include forming an annealed portion within or adjacent to a non-annealed portion, wherein a transition zone at least partially separates the annealed portion from the non-annealed portion and at least part, a majority, or substantially all the transition zone is less that 20 mm, less than 15 mm, approximately 10 mm, or less than 10 mm. Next, the part is moved 216 with the second transfer arm for later processing. The later processing includes deforming 218 the annealed portion. The step of deforming 218 may include one of cutting, riveting, bending, piercing, trimming to size, etc. The step of cutting may including laser cutting. The resulting part 220 may be a part of an automobile for example a pillar and more specifically a B-pillar.
[0039] FIG. 8 illustrates a part 300 having at least one non-annealed portion 302 with a small transition zone 304 that includes at least one deformation 306. More particularly, the part 300 is illustrated as a B-pillar with a transition zone 304 forming an outer edge that includes a deformation 306 including a cut along a peripheral edge of the transition zone 304.
[0040] FIG. 9 is a flowchart of a method 400 of forming a part with tailored temper properties and small transition zones. The method 400 begins by hot forming 402 and quenching 404 a blank in a hot forming die until it is a shaped part 401. The step of quenching 404 may include changing the microstructure of the shaped part. The method 400 continues by placing 406 the shaped part in an annealing die wherein it is partially cooled 408 and partially heated 410, simultaneously and at adjacent locations, until it is an annealed part 407 with a small transition zone between the annealed portions and the non-annealed portions. A portion of the annealed part that was heated 410 (i.e., an annealed portion of the annealed part) is then deformed 412.
[0041] It should be appreciated that the foregoing description of the embodiments has been provided for purposes of illustration. In other words, the subject disclosure it is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varies in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of disclosure.
