Press machine and method for manufacturing metal component

Abstract

This press machine includes: a first die disposed at a position facing one surface of a plate body conveyed along a first direction; a second die disposed so as to face the first die with the plate body interposed therebetween; and a recessed portion provided on at least one of the first die and the second die at a position facing an end portion of the plate body in a second direction intersecting the first direction, and extending in the first direction.

Description

Press working device and method for manufacturing metal parts

[0001] The technology of the present disclosure relates to a press working device and a method for manufacturing metal parts.

[0002] Some press working devices manufacture press-worked products by punching a desired shape from a strip-shaped plate using a mold. For example, Japanese Patent Application Laid-Open No. 2004-358490 describes a method of manufacturing a steel strip having a predetermined width by rolling a steel strip coil and then performing slitting.

[0003] The steel strip (corresponding to the plate body described later) manufactured by the method described in Japanese Patent Application Laid-Open No. 2004-358490 is manufactured by being cut by slitting. However, burrs and curl (hereinafter, these are collectively referred to as "burrs") may occur on the cut surface cut by the slitting. When the steel strip including the above-mentioned burrs is supplied to a press working device, the burrs may contact the mold and damage the mold during the conveyance of the steel strip, or the burrs may separate inside the press working device and remain inside the device, which may cause problems such as misalignment of the press working position and unintended indentations. In addition, warpage may occur around the cut portion in the slitting process, in which the end face deforms in the direction of sagging. The occurrence of such warpage may cause problems such as a decrease in processing accuracy during press working.

[0004] In view of the above problems, the present disclosure provides a press working device and a method for manufacturing metal parts that avoid problems caused by slitting even when the plate body is slit.

[0005] The press working device according to the first aspect includes a first mold disposed at a position facing one surface of a plate body conveyed along a first direction, a second mold disposed so as to face the first mold with the plate body sandwiched therebetween, and a recess extending in the first direction provided at a position facing an end portion of at least one of the first mold and the second mold in a second direction intersecting the first direction of the plate body.

[0006] In such a press working apparatus, even if burrs are present at the edges of the sheet metal in the second direction, the formation of recesses prevents contact between the burrs and the press working apparatus. This prevents scratches caused by the aforementioned burrs contacting the press working apparatus, and prevents burrs that have separated from the sheet metal upon contact with the press working apparatus from remaining inside the press working apparatus and getting stuck between the sheet metal and the die or punch, which can cause misalignment of the punching position or the occurrence of unintended indentations. Furthermore, even if warping occurs at the edges of the sheet metal in the second direction, the formation of recesses prevents contact between the warping and the press working apparatus, which can be expected to improve the processing accuracy during press working.

[0007] The press working apparatus according to the second embodiment is provided in the press working apparatus according to the first embodiment, wherein the recess is provided at a position facing the end of the sheet metal of the first die and the second die in the second direction.

[0008] In such a press working apparatus, if recesses are provided in both the first and second dies, the sheet metal can be placed in the press working apparatus without having to worry about the direction in which burrs or warping are generated, and the installation work becomes easier.

[0009] The press working apparatus according to the third embodiment is a press working apparatus according to the first or second embodiment, wherein the second die comprises a punch disposed above the sheet and movable toward the first die, and a stripper capable of supporting the sheet, and the recess is provided at a position of the stripper opposite to the end of the sheet in the second direction.

[0010] In such a press working apparatus, it becomes easier to form a recess on the second die side.

[0011] The press working apparatus according to the fourth embodiment further includes, in the press working apparatus according to any of the first to third embodiments above, a plurality of supports arranged at predetermined intervals along the first direction, which abut against the end of the plate in the second direction to position the plate in the second direction.

[0012] In such a press working apparatus, it is possible to suppress positional displacement of the sheet metal in the second direction.

[0013] The press working apparatus according to the fifth embodiment is the press working apparatus according to the fourth embodiment, wherein the support is composed of a rotating body that can rotate about a third direction intersecting the first direction and the second direction.

[0014] In such a press working apparatus, the sheet metal can be smoothly transported while suppressing positional displacement of the sheet metal in a second direction.

[0015] The press working apparatus according to the sixth embodiment is a press working apparatus according to any of the first to fifth embodiments, wherein the first die includes a first die body disposed below the sheet metal and a lifter capable of supporting the end of the sheet metal in the second direction and creating a gap between the sheet metal and the first die body, and the recess is provided on the lifter at a position facing the end of the sheet metal in the second direction.

[0016] In such a press working apparatus, by forming a recess in the lifter that supports the end of the sheet metal in the second direction, contact between the lifter and any burrs or warping that may form on the end of the sheet metal in the second direction can be avoided.

[0017] A method for manufacturing a metal part according to the seventh embodiment includes the steps of: transporting a plate having a predetermined thickness along a first direction such that one side thereof faces a first die; and performing press work on the plate by moving a second die, which is arranged to face the first die with the plate sandwiched between them, toward the first die, wherein at least one of the first die and the second die is provided with a recess extending in the first direction at a position facing the end of the plate in a second direction intersecting the first direction.

[0018] In this method for manufacturing metal parts, even if burrs or warping occur at the end of the plate body supplied between the first mold and the second mold in a second direction, contact between the burrs or warping and the first mold and the second mold can be avoided.

[0019] According to the press working apparatus and metal parts manufacturing method described above, even when a sheet metal is slit, problems caused by the slitting process can be avoided.

[0020] This is an explanatory diagram showing the waist portion of the manufacturing process for a sheet metal supplied to a press working machine. This is an example of an enlarged view of portion X in Figure 1A. This is another example of an enlarged view of portion X in Figure 1A. This is a schematic front view showing an example of a press working machine according to the first embodiment. This is a plan view showing the lower die of the press working machine in Figure 2. This is a cross-sectional view taken along the line A-A in Figure 2. This is a cross-sectional view taken along the line B-B in Figure 2. This is an enlarged view of portion C in Figure 5. This is a flowchart showing an example of a method for manufacturing a metal part according to the first embodiment. This is a schematic front view showing an example of a press working machine according to the second embodiment. This is a cross-sectional view taken along the line D-D in Figure 8.

[0021] This application is based on Japanese Patent Application No. 2025-016849, filed in Japan on February 4, 2025, the contents of which form part of the content of this application. The disclosure can be understood more fully by the following detailed description. Further applications of this application will become clear from the following detailed description. However, the detailed description and specific examples are preferred embodiments of the disclosure and are described for illustrative purposes only, for various changes and modifications will be obvious to those skilled in the art within the spirit and scope of the disclosure from this detailed description. The applicant has no intention of dedicating any of the described embodiments to the public, and any disclosed modifications or alternatives, even those not literally included in the claims, are considered part of the invention under the doctrine of equivalents. Similar reference numbers and names in various drawings indicate similar elements.

[0022] The following describes various embodiments for implementing this disclosure with reference to the drawings. In the following, only the necessary parts for explaining the objectives of this disclosure are schematically shown, and the explanation will primarily focus on the parts necessary for explaining the relevant sections of this disclosure. Any parts omitted from the explanation will be considered to be based on prior art. Furthermore, identical or equivalent components in the drawings are denoted by the same or similar reference numerals, and redundant explanations are omitted. Additionally, if multiple identical or equivalent components are included in the drawings, reference numerals may be assigned to only some of them for clarity.

[0023] Figures 1A to 1C are explanatory diagrams illustrating a part of the manufacturing process of a sheet metal supplied to a press working apparatus. Figure 1A is an explanatory diagram showing the main part of the manufacturing process, Figure 1B is an example of an enlarged view of portion X in Figure 1A, and Figure 1C is another example of an enlarged view of portion X in Figure 1A. Before describing each embodiment, an example of the manufacturing process of a sheet metal P1 supplied to a press working apparatus 1 (see Figure 2) according to the first embodiment, which will be described later, will be briefly explained with reference to Figures 1A to 1C. The sheet metal P1 used in this embodiment can be manufactured from a metal strip, such as a steel strip (sometimes called "strip steel") P0, which has a width sufficiently large to the width of the sheet metal P1 to be manufactured (about three times the width of the sheet metal P1 in Figure 1A), as shown in Figure 1A. Specifically, the steel strip P0 is rolled to a thickness that matches the thickness of the sheet metal P1 supplied to the press working apparatus 1 using a well-known rolling mill. The steel strip P0 used here may be made of coil material formed by rolling steel material into a roll shape. Furthermore, in the aforementioned rolling process, if the manufactured plate P1 is to be used in the manufacture of the core piece 2 (see Figure 2) described later, it is preferable to roll it so that its thickness is approximately 0.20 to 0.35 mm. In the example described above, a steel strip was used as the metal strip, but other metal strip members can also be used. The steel strip mentioned above may include electrical steel strip, spring steel strip, and amorphous steel strip.

[0024] Next, the rolled steel strip P0 is cut into multiple plates by slitting to the required width for the plate P1. For the aforementioned slitting process, a rotary slitter using a rotating blade can be used, for example.

[0025] In the aforementioned slitting process, a cutting method using a rotary blade is often employed. Therefore, burrs B may be generated on the cut surface of the plate body P1, specifically on the end PE in the width direction of the plate body P1, due to the cutting. As shown in Figure 1B, these burrs B are often formed to protrude upward or downward along the cut surface. Furthermore, the direction in which the burrs B protrude depends on the location of the plate body P1 in the width direction of the coil material before cutting (in other words, whether it was in the middle or at the end), making it difficult to control the direction of the burrs B in subsequent processes. Therefore, if a plate body P1 with burrs B formed on it is supplied directly to the press working apparatus 1, the burrs B may come into contact with the various components of the press working apparatus 1, potentially causing scratches on their surfaces.

[0026] Furthermore, in slitting, warping W may occur at the end portion including the cut surface, as shown in Figure 1C, where the end PE of the plate body P1 deforms in a downward direction. When such warping W occurs, the warping W may come into contact with the die surface and potentially damage the die. Also, if the plate body P1 is pressed while lifted from the die due to warping W, the position of the plate body P1 becomes unstable compared to when a flat plate body P1 is held down by the die, making it difficult to punch out the desired part of the plate body P1. As a result, the processing accuracy in press working may decrease. In particular, when punching out electrical steel strips, the electrical steel strips to be processed are relatively thin (for example, about 0.20 to 0.35 mm), making them prone to lifting due to warping W. In addition, when manufacturing core pieces 2 by punching out electrical steel strips, high punching accuracy is required. Therefore, the effects of warping W are particularly noticeable when processing electrical steel strips.

[0027] The press working apparatuses 1 and 1A according to the embodiments described below employ a structure to avoid processing defects caused by the burrs B or warping W. Several embodiments of this disclosure will be described in order below.

[0028] <First Embodiment> Figure 2 is a schematic front view showing an example of a press working apparatus 1 according to the first embodiment. In Figure 2, a part of it (specifically, the area around the second die 11B) is shown in cross-section to make the structure easier to understand. Also, in Figure 2, in order to facilitate understanding of the structure, the detailed shapes of each component of the press working apparatus 1 and the core piece 102 are omitted and a simplified version is shown. Figure 2 illustrates a press working apparatus 1 according to this embodiment that is capable of continuously manufacturing core pieces 2 that constitute a motor core by stacking multiple sheets P1 obtained through the manufacturing process described above. In the following description, the direction indicated by arrow X in Figure 2 will be considered the left-right direction, and similarly, the direction indicated by arrow Y will be considered the front-back direction, and the direction indicated by arrow Z will be considered the up-down direction.

[0029] As shown in Figure 2, the press working apparatus 1 according to this embodiment includes at least a lower die 10, which is an example of a first die, positioned opposite the lower surface of a sheet metal P1 that is conveyed along the left-right direction, and an upper die 20, which is an example of a second die, positioned opposite the lower die 10 with the sheet metal P1 in between. The lower surface of the sheet metal P1 mentioned above is an example of "one side of the sheet metal".

[0030] Figure 3 is a plan view showing the lower die of the press working apparatus shown in Figure 2. In Figure 3, only the lower die 10 and the sheet metal P1 being transported on the lower die 10 are shown, and the upper die 20 and the transport support mechanisms 40, 40 described later are omitted from the illustration. As shown in Figures 2 and 3, the lower die 10 may be a long member along the transport direction of the sheet metal P1 (indicated by arrow A1 in Figure 2) on which the sheet metal P1 is transported. The lower die 10 may include one or more dies 11A, 11B and a die holder 12 that supports the dies 11A, 11B. In the lower die 10 shown in Figure 3, two dies 11A, 11B are arranged side by side along the left-right direction, and the sheet metal P1 is transported on the upper part of these two dies 11A, 11B. The first die 11A located on the upstream side in the transport direction of the sheet metal P1 may be used, for example, to punch through holes to be formed in the core piece 2. Furthermore, the second die 11B, located downstream in the conveying direction of the plate body P1, can be used to punch out a portion of the core piece 2 in order to separate the core piece 2 from the plate body P1. The conveying direction described above is just one example of the "first direction," and this direction corresponds to the left-right direction in Figure 2 and other figures mentioned above.

[0031] Furthermore, a squeeze 13 capable of supporting the core piece 2 punched out by the second die 11B may be provided at the lower part of the second die 11B. The squeeze 13 may be made of a cylindrical member, and the inner wall of the squeeze 13 may press against the side surface of the core piece 2 passing through the squeeze 13, thereby transporting the core piece 2 downward in a substantially horizontal position. This squeeze 13 may be supported by the die holder 12 together with the die 11B.

[0032] Below the squeeze 13, a receiving member 14 may be provided to receive the core pieces 2 being discharged from the lower end of the squeeze 13. The receiving member 14 is replaced when a predetermined number of core pieces 2 have been placed on it, thereby enabling the stack of core pieces 2 to be transported to the next process, etc. The squeeze 13 and receiving member 14 described above are merely examples of components for transporting the core pieces 2 punched out by the second die 11B, and can be changed to other components with similar functions or omitted.

[0033] The upper die 20 may be a member that is elongated in the left-right direction in Figure 2, and is disposed on the upper part of the plate body P1 so as to face the upper surface of the lower die 10. The upper die 20 may include at least one or more punches 21A, 21B disposed above the plate body P1 and movable at least in the direction approaching the lower die 10, i.e., downward, and a stripper 22 disposed above the plate body P1 in the same way as the punches 21A, 21B and capable of supporting the plate body P1 at a predetermined timing.

[0034] The punches 21A and 21B are positioned opposite the dies 11A and 11B of the lower die 10 and can be made of substantially columnar or cylindrical members that can punch out the sheet metal P1 into a predetermined shape by moving toward the dies 11A and 11B (indicated by arrow A2 in Figure 2). The punches 21A and 21B of this embodiment include a first punch 21A positioned opposite the first die 11A and a second punch 21B positioned opposite the second die 11B. These punches 21A and 21B may be able to move vertically by being connected to a press machine 24 in which the base end is fixed to a punch holder 23 and the punch holder 23 is movable vertically.

[0035] The stripper 22 may be a member for supporting the plate body P1 when the plate body P1 is punched out by the punches 21A, 21B and dies 11A, 11B. The stripper 22 can be made of a plate body having a predetermined thickness. The stripper 22 may also be elastically supported by a plurality of guide pins 25 extending downward from the lower surface of the punch holder 23 via springs or the like (not shown), and the lower surface of the stripper 22 may be positioned slightly below the lower surface of the punches 21A, 21B when the springs or the like are at their natural length. Through holes 26 (see Figure 4) may be formed in the stripper 22 at the positions where the punches 21A, 21B are provided, through which the tips of the punches 21A, 21B can pass. The plurality of guide pins 25 are rod-shaped members that guide the vertical movement of the stripper 22, and a plurality of them may be arranged at appropriate locations other than the positions where the punches 21A, 21B are provided.

[0036] The stripper 22 described above can descend and ascend together with the punches 21A and 21B, and supports the plate P1 while the punches 21A and 21B punch it out by contacting the upper surface of the plate P1 just before the tips of the punches 21A and 21B come into contact with the plate P1. The stripper 22 stops its descending motion when it comes into contact with the upper surface of the plate P1. Furthermore, when the punches 21A and 21B ascend after the punching operation described above, the stripper 22 maintains contact with the upper surface of the plate P1 until the punches 21A and 21B separate from the plate P1, thereby supporting the separation of the punches 21A and 21B from the plate P1.

[0037] When punching out the core piece 2 from the sheet metal P1 using the lower die 10 and upper die 20 described above, the lower surface of the sheet metal P1 contacts the upper surface of the lower die 10, and the upper surface of the sheet metal P1 contacts the lower surface of the upper die 20. If the sheet metal P1 contains the burrs B described above, the burrs B or warp W will be generated at a position that contacts the upper surface of the lower die 10 or the lower surface of the upper die 20. If the upper surface of the lower die 10 and the lower surface of the upper die 20 are flat surfaces, there is a high possibility that they will come into contact with these surfaces and cause scratches. Also, if the burrs B come into contact with the lower die 10 or the upper die 20, there is a possibility that the burrs B will separate from the sheet metal P1. The burrs B that have been separated in this way are likely to remain inside the press working apparatus 1, and if they get caught between the punches 21A, 21B or dies 11A, 11B and the sheet metal P1, for example, they may cause unintended dents to be generated on the sheet metal P1. In this embodiment, in view of the above, recesses 31 and 32 are formed in at least one of the lower mold 10 and the upper mold 20 so that the end PE in the width direction of the plate body P1, the burrs B or warping W formed on PE do not come into contact with the lower mold 10 and the upper mold 20. In other words, the recesses 31 and 32 are capable of accommodating the end PE in the width direction of the plate body P1, the burrs B or warping W formed on PE. The width direction mentioned above is an example of the "second direction" and corresponds to the front-rear direction in Figure 2, etc.

[0038] Figure 4 is a cross-sectional view taken along the line A-A in Figure 2. The recesses 31 and 32 in this embodiment include a lower die side recess 31 formed on the upper surface of the lower die 10 and an upper die side recess 32 formed on the lower surface of the upper die 20, as shown in Figure 4. In Figure 4, a case in which burrs B are formed on the ends PE, PE of the plate body P1 is shown as an example, but warping W may occur instead of burrs B. In this embodiment, the case in which both the lower die side recess 31 and the upper die side recess 32 are used as recesses is shown as an example, but it is also possible to use only the lower die side recess 31 or only the upper die side recess 32. In that case, it is advisable to adjust the vertical orientation of the plate body P1 in advance so that the burrs B or warping W formed on the plate body P1 supplied to the press working apparatus 1 are located within the recesses.

[0039] As shown in Figures 3 and 4, the lower mold side recess 31 can be made up of a groove that extends along the transport direction of the plate body P1 being transported on the lower mold 10, provided at the end PE in the width direction of the plate body P1, opposite to PE. The depth and width of the lower mold side recess 31 are not particularly limited as long as they are large enough to accommodate the burrs B or warping W within the lower mold side recess 31 and the burrs B or warping W do not come into contact with the lower mold side recess 31, for example, they can both be a few millimeters. The depth and width of the lower mold side recess 31 should be adjusted appropriately considering the size of the burrs B or warping W that may occur on the plate body P1.

[0040] The upper mold side recess 32 may be provided in the upper mold 20, particularly in the stripper 22, as shown in Figure 4. Similar to the lower mold side recess 31, this upper mold side recess 32 can also be made up of a groove extending along the conveying direction of the plate body P1, provided at the end PE in the width direction of the plate body P1 of the stripper 22, at a position facing PE. Furthermore, the depth and width of the upper mold side recess 32 may be adjusted in the same way as the depth and width of the lower mold side recess 31.

[0041] In this embodiment, the press working apparatus 1 employs the lower die side recess 31 and the upper die side recess 32 described above, so that even if burrs B or warping W are formed on the sheet metal P1, the burrs B or warping W will not come into contact with the lower die 10 or the upper die 20. This prevents scratches from occurring due to contact between the burrs B or warping W and the lower die 10 or the upper die 20, or the burrs B separating from the sheet metal P1 due to the aforementioned contact and remaining inside the press working apparatus 1. Furthermore, since recesses 31 and 32 are provided on both the lower die 10 and the upper die 20, contact between the burrs B or warping W and the lower die 10 or the upper die 20 can be avoided regardless of the orientation of the burrs B or warping W formed on the sheet metal P1.

[0042] Incidentally, if a misalignment occurs in the width direction of the sheet metal P1 installed in the press working apparatus 1, the positions of the end portions PE, PE in the width direction of the sheet metal P1 will shift, and the burrs B or warps W formed on the end portions PE, PE may come into contact with the wall surface of the recess 31, depending on the size of the recess 31. Therefore, the press working apparatus 1 according to this embodiment may further include a transport support mechanism 40 for supporting and positioning the sheet metal P1 during transport.

[0043] As shown in Figure 2, the transport support mechanism 40 in this embodiment is installed on the downstream and upstream sides in the transport direction of the lower die 10. However, the arrangement of the transport support mechanism 40 is not limited to this, and it can also be installed in the middle of the lower die 10 in the transport direction, or on only one of the upstream or downstream sides in the transport direction of the lower die 10. The transport support mechanism 40 may have a structure that can restrict the position of the plate body P1, particularly in the width direction.

[0044] FIG. 5 is a cross-sectional view taken along line B-B of FIG. 2. Further, FIG. 6 is an enlarged view of part C of FIG. 5. Further, as shown in FIGS. 5 and 6, the conveyance support mechanism 40 may include a lower plate 41 that supports the position of the lower surface of the plate body P1, an upper plate 42 that is supported above the end portion in the width direction of the lower plate 41, and a support body 43 that is supported between the lower plate 41 and the upper plate 42. In addition, the conveyance support mechanism 40 may be configured to be movable in the vertical direction as a whole, so that, for example, the lower surface of the plate body P1 and the upper surface of the lower die 10 can be separated when the plate body P1 is conveyed.

[0045] The lower plate 41 may be configured to support from below the portion of the plate body P1 before being conveyed onto the upper surface of the lower die 10 or the portion after being conveyed from the upper surface of the lower die 10. The lower plate 41 may be provided with support protrusions 41A, 41A that support from below the end portions PE, PE in the width direction of the plate body P1 and the positions adjacent thereto. The positions of the support protrusions 41A, 41A are preferably provided at positions that are not punched by the second punch 21B in the width direction of the plate body P1 so that the plate body P1 after the core piece 2 is punched can also be reliably supported. Further, a plurality of the support protrusions 41A, 41A may be arranged at predetermined intervals along the conveyance direction.

[0046] The upper plate 42 is provided so as to cover above the end portion in the width direction of the lower plate 41, and preferably, the inner end portion in the width direction thereof extends to a position that covers the end portions PE, PE in the width direction of the plate body P1 that is conveyed on the lower plate 41 in a plan view. The distance between the upper plate 42 and the lower plate 41 is preferably adjusted to be sufficiently larger than the thickness of the plate body P1 so that, for example, the upper plate 42 does not impede the conveyance of the plate body P1. Note that this upper plate 42 can also be omitted.

[0047] A plurality of support bodies 43 are arranged at predetermined intervals along the conveyance direction of the plate body P1, and by abutting against the end portions PE, PE in the width direction of the plate body P1, positioning in the width direction of the plate body P1 is performed. Although a plurality of support bodies 43 are arranged along the conveyance direction of the plate body P1, when the press working apparatus 1 has a plurality of conveyance support mechanisms 40 as in the present embodiment, one may be provided at each width direction end portion of each conveyance support mechanism 40 respectively.

[0048] Further, it is preferable that the support body 43 is constituted by a rotating body including an axial center 44 extending in the vertical direction supported between the lower plate 41 and the upper plate 42, a support body main body 45 rotatable about the axial center 44, and a cushioning material 46 formed on the outer peripheral surface of the support body main body 45. When the support body 43 is constituted by a rotating body, when the end portions PE, PE in the width direction of the plate body P1 come into contact with the support body 43, it is preferable that the width direction position of the plate body P1 can be guided to an appropriate position while continuing the conveyance of the plate body P1. Of course, the support body 43 only needs to be able to guide the width direction position of the plate body P1 and is not limited to the above-described form.

[0049] In order for the burr B or warp W of the plate body P1 not to come into contact with the conveyance support mechanism 40 including the above-described configuration, it is preferable to adopt recesses similar to the above-described lower die side recess 31 and upper die side recess 32 in the conveyance support mechanism 40 as well. Specifically, as shown in FIG. 6, a lower plate side recess 33 is provided at a position of the lower plate 41 facing the end portions PE, PE in the width direction of the plate body P1, and an upper plate side recess 34 is provided at a position of the upper plate 42 facing the end portions PE, PE in the width direction of the plate body P1. It is preferable that at least one end in the extending direction of the lower plate side recess 33 is at least temporarily continuous with the lower die side recess 31, and it is preferable that at least one end in the extending direction of the upper plate side recess 34 is at least temporarily continuous with the upper die side recess 32. In this regard, the dimensions of the lower plate side recess 33 are preferably adjusted in the same manner as the lower die side recess 31, and the dimensions of the upper plate side recess 34 are preferably adjusted in the same manner as the upper die side recess 32. By providing the above-described lower plate side recess 33 and upper plate side recess 34, contact between the conveyance support mechanism 40 and the burr B or warp W of the plate body P1 can also be avoided.

[0050] Furthermore, the press working apparatus 1 of this embodiment may further include a control device 50 to control each of the above-mentioned components. This control device 50 may be connected to each component via wired or wireless communication, for example, as shown by the dotted lines in Figure 2. A well-known computer can be used for the control device 50. This well-known computer may include at least a processor, volatile and non-volatile memory, and various interfaces.

[0051] Next, the method for manufacturing metal parts according to this embodiment will be briefly described below, mainly with reference to Figure 7. In the method for manufacturing metal parts described below, the case in which metal parts such as motor cores and leaf springs are manufactured using the press working apparatus 1 described above will be described as an example. In this regard, the method for manufacturing metal parts according to this embodiment can be realized by the control device 50 of the press working apparatus 1 executing a predetermined program stored, for example, in the memory of the control device 50. In the following description, the case in which the method for manufacturing metal parts according to this embodiment is carried out using the press working apparatus 1 described above is an example, but the press working apparatus used is not limited to the press working apparatus 1 described above. Furthermore, the following explanation of the effects of the method for manufacturing metal parts also serves as an explanation of the effects of the press working apparatus 1 described above.

[0052] Figure 7 is a flowchart showing an example of a method for manufacturing a metal part according to the first embodiment. The method for manufacturing a metal part according to this embodiment includes at least the steps of: transporting a plate body P1 having a predetermined thickness along the left-right direction so that one side of the plate body P1 faces the lower die 10 (corresponding to step S02 described later); and moving an upper die 20, which is arranged to face the lower die 10 with the plate body P1 in between, toward the lower die 10, to perform press working on the plate body P1 (corresponding to step S03 described later). A detailed explanation follows below.

[0053] When the processing method according to this embodiment is started, as shown in Figure 7, first a plate body P1, which will be the material for the core piece 2, is placed on the upper surface of the lower die 10 of the press working apparatus 1 (step S01). At this time, it is preferable that the plate body P1 is positioned such that its end portions PE, PE in the width direction are located above the recess 31 on the lower die side.

[0054] Next, the conveyance of the plate P1 along a predetermined conveyance direction is started (step S02). This conveyance can be achieved by a conveyance device (not shown). The plate P1 being conveyed by the conveyance device is stopped each time it travels a predetermined distance along the conveyance direction, specifically the distance between adjacent dies 11A and 11B.

[0055] When the transport of the sheet metal P1 stops, the upper die 20 is lowered to perform a punching operation on the sheet metal P1 (step S03). As the upper die 20 lowers, the punches 21A, 21B and the stripper 22 also lower. When the lower surface of the stripper 22 contacts the upper surface of the sheet metal P1, the lowering movement of the stripper 22 stops. As the upper die 20 lowers further, the sheet metal P1 is sandwiched between the punches 21A, 21B and the dies 11A, 11B, and then punched out into a predetermined shape. When the stripper 22 and the sheet metal P1 come into contact, the upper die side recess 32 formed in the stripper 22 covers the upper part of the end PE, PE in the width direction of the sheet metal P1.

[0056] Once the punching operation described above is complete, the upper die 20 is raised (step S04). Then, when the upper die 20 is raised and the punches 21A and 21B are separated from the plate body P1, the process returns to step S02 and the previously described steps are executed in succession.

[0057] As described above, according to the manufacturing method of metal parts of this embodiment, by providing recesses 31 to 34 in the press working apparatus 1, the end portions PE, PE in the width direction of the plate body P1 are prevented from always coming into contact with the press working apparatus 1. Therefore, it is possible to prevent burrs B or warping W that may be formed on the end portions PE, PE from scratching the components of the press working apparatus 1, and to prevent burrs B separated from the plate body P1 from remaining inside the press working apparatus 1.

[0058] <Second Embodiment> In the first embodiment described above, a press working apparatus 1 was illustrated for manufacturing core pieces 2 constituting a motor core from a plate P1 by press working. However, it is also possible to manufacture metal members other than core pieces 2. Below, a press working apparatus 1A capable of manufacturing a leaf spring 3 from a plate P2 will be illustrated with reference to Figures 8 and 9 as a second embodiment of the present disclosure. In the following, components of the press working apparatus 1A according to the second embodiment that are the same as those of the press working apparatus 1 according to the first embodiment will be denoted by the same reference numerals and their descriptions will be omitted, and the explanation will focus on components unique to the second embodiment.

[0059] Figure 8 is a schematic front view showing an example of a press working apparatus according to the second embodiment. The press working apparatus 1A according to this embodiment, as shown in Figure 8, includes at least a lower die 10A as an example of a first die, which is positioned opposite the lower surface of the plate body P2 that is conveyed along the left-right direction, and an upper die 20A as an example of a second die, which is positioned opposite the lower die 10A with the plate body P2 in between. The plate body P2 used in this embodiment may be produced by cutting from a steel strip P0 by slitting or the like, similar to the plate body P1 described above. On the other hand, the plate body P2 may have a greater thickness than the plate body P1.

[0060] The lower mold 10A includes a lower mold body 15 disposed below the plate body P2, and a pair of lifters 16, 16 that support the end portions PE, PE in the width direction of the plate body P2 and are capable of forming a gap G between the plate body P2 and the lower mold body 15.

[0061] Figure 9 is a cross-sectional view taken along the line D-D in Figure 8. In Figure 9, the size of the pair of lifters 16, 16 is shown larger than the actual size in order to make the structure of the pair of lifters 16, 16 easier to understand. The lower die body 15 may include at least one or more dies 11A, 11B and a die holder 12, as shown in Figures 8 and 9. In addition, lifter housing grooves 15A, 15A extending along the conveying direction are formed at the widthwise ends of the lower die body 15. Since these lifter housing grooves 15A, 15A are formed at positions corresponding to the widthwise ends PE, PE of the plate body P2 that is conveyed on the lower die body 15, the lower die body 15 does not come into contact with the widthwise ends PE, PE of the plate body P2.

[0062] As shown in Figure 9, the pair of lifters 16, 16 are housed in lifter housing grooves 15A, 15A, respectively, and may be able to move vertically as indicated by arrow A3. The upper parts of the pair of lifters 16, 16 may be provided with insertion grooves 17 on opposing surfaces into which the end portions PE, PE in the width direction of the plate body P2 can be inserted. The lower surface of the insertion groove 17 can constitute a mounting surface 17A on which the plate body P2 is placed, and the upper surface can constitute a pressing surface 17B that restricts the upward movement of the plate body P2 together with the punches 21A, 21B.

[0063] On at least one of the mounting surface 17A and the pressing surface 17B of the insertion groove 17, recesses 35 and 36 are formed, extending along the transport direction of the plate body P2 (the direction indicated by arrow A1 in Figure 8) at positions facing the end PE in the width direction of the plate body P2. In this embodiment, the recesses 35 and 36 consist of a lower lifter recess 35 provided on the mounting surface 17A side and an upper lifter recess 36 provided on the pressing surface 17B side.

[0064] The depth and width of the lower recess 35 and the upper recess 36 of the lifter are not particularly limited, as long as they are large enough to accommodate the burrs B or warping W within the recesses 35 and 36 and the burrs B or warping W do not come into contact with the recesses 35 and 36, similar to the lower mold side recess 31 and the upper mold side recess 32 described above. As described above, by forming the recesses 35 and 36 described above in the pair of lifters 16, 16, contact between the lifter 16 and the end portion PE of the plate body P2 in the width direction can be avoided.

[0065] The upper die 20A may be composed of a long member in the left-right direction, disposed on the upper part of the plate body P2 so as to face the upper surface of the lower die 10A. The upper die 20A is the same as the upper die 20 described above in that it has one or more punches 21A, 21B that are movable in the direction toward the lower die 10A. On the other hand, the upper die 20A does not have the stripper 22 included in the upper die 20. In connection with this, the upper die 20A of this embodiment does not have a recess formed at a position facing the end PE in the width direction of the plate body P2 as described above.

[0066] In the press working apparatus 1A with the above-described configuration, at least when the sheet metal P2 is conveyed along the conveying direction, it is moved upward from the lower die body 15 by the pair of lifters 16, 16. In connection with this, the end portions PE, PE in the width direction of the sheet metal P2 do not come into contact with any components of the press working apparatus 1A other than the pair of lifters 16, 16. Furthermore, since the insertion grooves 17 of the pair of lifters 16, 16 are provided with a lower lifter recess 35 and an upper lifter recess 36 at positions facing the end portions PE, PE in the width direction of the sheet metal P2, the end portions PE, PE in the width direction of the sheet metal P2 do not come into contact with the pair of lifters 16, 16. Therefore, the press working apparatus 1A of this embodiment can also obtain the same effects as the press working apparatus 1 of the first embodiment described above.

[0067] In the press working apparatus 1A described above, an example was given in which two recesses, the lower lifter recess 35 and the upper lifter recess 36, are used as recesses. However, it is also possible to use only the lower lifter recess 35 or only the upper lifter recess 36. Furthermore, a conveying support mechanism similar to the one described in the first embodiment can be used in an appropriate place in the press working apparatus 1A. In addition, a stripper similar to the one described in the first embodiment can be used in the upper die 20A of the press working apparatus 1A. However, when a stripper is used in the upper die 20A, it is preferable to adjust the width and shape of the stripper so that it does not come into contact with the end PE, PE in the width direction of the plate body P2.

[0068] Furthermore, the lifters 16, 16 provided in the press working apparatus 1A can also be used in appropriate locations in the press working apparatus 1 according to the first embodiment. In that case, it is preferable to provide through holes for housing the lifters 16, 16 in the portion of the lower die 10 where the lifters 16, 16 are placed.

[0069] This disclosure is not limited to the embodiments described above, and can be implemented with various modifications without departing from the spirit of this disclosure. All such modifications are included in the technical concept of this disclosure. Furthermore, unless otherwise specified in the specification, each component of this disclosure is not limited to one, but may exist in multiple forms.

[0070] All documents cited herein, including publications, patent applications, and patents, are incorporated here by reference to the same extent as each document is individually and specifically identified and its contents are described herein.

[0071] The use of nouns and similar demonstrative pronouns in connection with the description of this disclosure (particularly in connection with the following claims) shall be construed as both singular and plural unless otherwise specifically noted herein or if it is clearly inconsistent with the context. The words “equip,” “have,” “include,” and “incorporate” shall be construed as open-ended terms (i.e., “include, but not limited to”) unless otherwise specifically noted herein. The numerical ranges described herein are intended solely as abbreviations for referring individually to each value that falls within that range, unless otherwise specifically noted herein, and each value is incorporated into the specification as if it were individually enumerated herein. All methods described herein can be performed in any appropriate order unless otherwise specifically noted herein or if it is clearly inconsistent with the context. Any examples or illustrative phrases used herein (e.g., “etc.”) are intended solely to better illustrate this disclosure and not to impose any limitations on the scope of this disclosure unless otherwise specifically asserted. Nothing in the specification shall be construed as indicating that any element not described in the claims is essential to the implementation of this disclosure.

[0072] This specification describes preferred embodiments of the Disclosure, including the best mode known to the inventors for carrying out the Disclosure. Those skilled in the art will see, upon reading the above description, that variations of these preferred embodiments will become apparent. The inventors expect that skilled individuals will appropriately apply such variations and that the Disclosure will be carried out in ways other than those specifically described herein. Therefore, this Disclosure includes all modifications and equivalents of the claims appended to this Specification, as permitted by applicable law. Furthermore, any combination of the above elements in all variations is incorporated into this Disclosure unless specifically noted herein or is obviously inconsistent with the context.

Claims

1. A press working apparatus comprising: a first die disposed at a position facing one side of a sheet metal being conveyed along a first direction; a second die disposed opposite the first die, sandwiching the sheet metal between them; and a recess extending in the first direction, provided at a position facing the end of the sheet metal in a second direction intersecting the first direction in at least one of the first die and the second die.

2. The press working apparatus according to claim 1, wherein the recess is provided at a position opposite to the end of the plate body of the first die and the second die in the second direction.

3. The press working apparatus according to claim 1, wherein the second die comprises a punch disposed above the sheet and movable toward the first die, and a stripper capable of supporting the sheet, and the recess is provided on the stripper opposite to the end of the sheet in the second direction.

4. The press working apparatus according to claim 1, further comprising a plurality of supports arranged at predetermined intervals along the first direction, which abut against the end of the plate in the second direction to position the plate in the second direction.

5. The press working apparatus according to claim 4, wherein the support is composed of a rotating body that can rotate about a third direction intersecting the first direction and the second direction.

6. The press working apparatus according to claim 1, wherein the first die comprises a first die body disposed below the plate body, and a lifter capable of supporting the end of the plate body in the second direction and creating a gap between the plate body and the first die body, and the recess is provided on the lifter at a position opposite to the end of the plate body in the second direction.

7. A method for manufacturing a metal part, comprising the steps of: conveying a plate having a predetermined thickness along a first direction such that one side thereof faces a first die; and performing press work on the plate by moving a second die, which is disposed opposite the first die with the plate sandwiched between them, toward the first die, wherein at least one of the first die and the second die is provided with a recess extending in the first direction at a position facing the end of the plate in a second direction intersecting the first direction.

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