Metal processing device and metal processing method

Abstract

The pressing part (11), which is formed into a cone shape with a tapered tip, pushes the metal material of the predetermined opening portion (5) away from the radial center toward the outer diameter direction. The pushed-away portion (2b) has a higher density than the other parts of the sheet (2) and is thus work-hardened (base material hardening). At the periphery of the predetermined opening portion (5), the radial dimension (c2) of the work-hardened portion is larger than the radial dimension (c1) of the pressing part (11) (c1 < c2).

Description

Technical Field

[0013] , Figure 1 , , , ,

[0014]

[0001] The present invention relates to a metal processing apparatus and a metal processing method. Background Art

[0002] As a conventional metal processing apparatus, there is known an apparatus that forms a hole in a metal plate by a shearing blanking method using a punch and a die (for example, refer to Patent Document 1). In such an apparatus, the corner of the punch is formed into a curved surface and a conical concave surface is provided at the front end. Thereby, cracks and fractures are prevented from occurring on the shearing cut surface of the hole.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2002-120025 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] Conventional metal processing tools cause a burr that forms a rounded corner in the radial direction at the periphery of the punched hole. In addition, when a plurality of holes are adjacently formed, the metal material between the holes sinks and material retraction (Japanese: material drawing-in) occurs.

[0008] Therefore, in order to reduce burrs and material retraction, further improvement is required.

[0009] An object of the present invention is to provide a metal processing apparatus and a metal processing method that can reduce burrs and material retraction.

[0010] Means for Solving the Problems

[0011] The present invention includes: a forging tool that work-hardens a predetermined opening portion of a workpiece by forging; and a blanking tool that punches and forms an opening portion at the predetermined opening portion. The blanking tool has an insertion portion having the same diameter as the opening portion and a shoulder portion that is continuously provided with the insertion portion and has a diameter larger than that of the insertion portion as it approaches the base end side of the blanking tool. When punching and forming the opening portion, the blanking tool is inserted until the shoulder portion abuts against the work-hardened portion remaining on the inner periphery of the opening portion from the inner side surface.

[0012] Effects of the Invention

[0013] According to the present invention, there is provided a metal processing apparatus and a metal processing method that can reduce burrs and material retraction. BRIEF DESCRIPTION OF THE DRAWINGS <​​

[0015] Figure 2 This is a schematic cross-sectional view illustrating the main parts of the blanking process using a blanking tool in the embodiment.

[0016] Figure 3 This is a schematic cross-sectional view illustrating the main parts of the tapping process using a tapping tool in the embodiment.

[0017] Figure 4 This is a schematic cross-sectional view of the main part of a metal plate in an embodiment where the opening is machined flat.

[0018] Figure 5 This is a top view of a metal plate with multiple openings arranged adjacent to each other in the embodiment.

[0019] Figure 6 In the implementation method along Figure 5 A cross-sectional view of the metal plate at the location of line VI-VI.

[0020] Figure 7 It indicates a comparative example and is related to Figure 6 A cross-sectional view of a metal plate at a corresponding location.

[0021] Figure 8 This is a side view showing the main part of an example of a punching tool.

[0022] Figure 9A This is a schematic cross-sectional view of the main part, showing a variation of the forging tool of the embodiment and illustrating the case where a metal sheet is work-hardened by forging using a forging tool with a flat end face.

[0023] Figure 9B It is a schematic cross-sectional view showing a forging tool with a tapered tip and no flat portion around it.

[0024] Figure 9C This is a schematic cross-sectional view showing a forging tool with a chamfered bevel formed on the outer periphery of a flat end face. Detailed Implementation

[0025] Hereinafter, an embodiment of the present invention will be described with appropriate reference to the accompanying drawings. Identical components are labeled with the same reference numerals, and repeated descriptions are omitted.

[0026] The metal processing apparatus 1 holds the sheet metal 2, which is the workpiece, in place by a clamping fixture (not shown). In this state, the following steps are performed sequentially: a forging step in which the predetermined opening portion 5 is forged and hammered to work harden it; a punching step in which the opening portion 3 is formed by punching the forged predetermined opening portion 5 of the sheet metal 2; and a hammering step in which the fine protrusions 6 generated around the punched opening portion 3 are hammered by a hammering tool to flatten them.

[0027] The metal processing apparatus 1 of this embodiment undergoes various processes, such as... Figure 5 The sheet material 2 shown has multiple openings 3 extending outwards. Thus, the sheet material 2 becomes a sheet product 4 with 3×4 openings, totaling 12 openings 3, spaced equally horizontally and vertically, forming a grid pattern (see reference). Figure 5 In this embodiment, the relationship between the aperture, plate thickness, and spacing of the opening 3 is set such that the aperture is smaller than the plate thickness and the spacing is less than three times the aperture.

[0028] Furthermore, for ease of explanation, this embodiment primarily illustrates the case where an opening 3 is formed on the plate 2. Descriptions of other openings 3 formed similarly are omitted.

[0029] First, the structure of the forging tool 10 used in the forging process will be described.

[0030] The metal processing apparatus 1 is equipped with a clamping fixture (not shown) that horizontally holds and fixes the sheet metal 2, and a sliding moving body. The sliding moving body moves along the sliding direction (with the forging tool 10 installed) Figure 1 (Use the up and down direction) to move the forging tool 10.

[0031] The forging tool 10 has a pressing part 11 at its lower end and a flat part 12 located around the periphery of the pressing part 11.

[0032] In this embodiment, the pressing part 11 is provided with a front end 11a that is tapered into a cone shape and located at the bottom on the central axis S in the radial center.

[0033] By mounting the pushing part 11 to the sliding moving body, the front end 11a faces the predetermined opening portion 5 of the plate 2, which is horizontally fixed by the clamping fixture and becomes the opening portion 3 when it is completed as a plate-shaped product 4.

[0034] Then, when the sliding body moves downward in the sliding direction, the pressing part 11 of the forging tool 10 abuts the conical front end 11a against a portion 2a of the upper surface of the plate 2, and pushes the predetermined opening portion 5 from above.

[0035] The pressing part 11, which is formed into a cone shape with a tapered tip, pushes the metal material of the predetermined opening portion 5 from the radial center toward the outer diameter direction. The pushed-out portion 2b has a higher density than other parts of the sheet 2 and thus undergoes work hardening (base material hardening).

[0036] Around the periphery of the predetermined opening portion 5, the radial dimension c2 of the work-hardened portion is larger than the radial dimension c1 of the pressing portion 11 (c1 < c2).

[0037] Furthermore, an annular flat portion 12 is provided around the pressing portion 11 in this embodiment. The flat portion 12 is provided parallel to the plate 2 mounted on the clamping fixture. Moreover, when the plate 2 is forged by the pressing portion 11, the flat portion 12 abuts against the periphery of the predetermined opening portion 5 from above.

[0038] The flat portion 12 abuts against the periphery of the predetermined opening portion 5, and the clamping fixture supported below pushes the plate 2 downward from the out-of-plane direction. As a result, the metal material at the periphery of the predetermined opening portion 5 is prevented from moving upward in the out-of-plane direction, promoting work hardening.

[0039] like Figure 2 As shown, the metal processing apparatus 1 of this embodiment includes a blanking tool 20 for a blanking process. The blanking tool 20 blanks to form an opening 3 in a predetermined opening portion 5 in the sheet metal 2.

[0040] The blanking tool 20 integrally includes: a cylindrical insertion portion 22 located on the front end (lower end) side, having a diameter approximately equal to the radial dimension c1 of the pressing portion 11 of the forging tool 10; a base end portion 24 on the base end (upper end) side, having a diameter larger than that of the insertion portion 22, mounted on a sliding moving body and moving together with sliding movement in the vertical direction; and a shoulder portion 26 continuously provided between the insertion portion 22 and the base end portion 24 above the sliding direction (vertical direction) of the insertion portion 22.

[0041] Among them, the tilt angle α2 of shoulder 26 is compared with Figure 1 The tilt angle α1 of the pusher portion 11 shown is small (α1 > α2). In this embodiment, α1 is set to approximately 45 degrees and α2 to approximately 10 degrees.

[0042] like Figure 8 As shown, a curved surface 28 is formed on the shoulder portion 26 in this embodiment. The curved surface 28 is formed to expand outward as it moves from the insertion portion 22 toward the base portion 24.

[0043] The expansion ratio of the curved surface 28 (the increased radius dimension r / sliding dimension h) is set to gradually increase as it moves from the insertion part 22 toward the base end part 24.

[0044] For example, if the dimensions in the sliding direction of each part on the curved surface 28 are made equal (h1 = h2 = h3), then the increase in the radius direction of each part gradually increases (r1 < r2 < r3).

[0045] Therefore, the expansion ratio of the curved surface 28 is minimized on the connecting portion side connected to the insertion portion 22, and is flush with the side surface of the insertion portion 22. Furthermore, the expansion ratio of the curved surface 28 is maximized on the connecting portion side connected to the base end portion 24.

[0046] like Figure 2 As shown, the punching tool 20 punches the opening 3 by bringing the insertion portion 22 abutting against the work-hardened portion of the opening predetermined portion 5. At this time, the opening 3 is preferably housed within the work-hardened area of ​​the opening predetermined portion 5.

[0047] The insert 22 of the punching tool 20 punches the sheet metal 2 on the lower surface side by inserting it in the sliding direction, while retaining the work-hardened metal material with increased density around it.

[0048] When the shoulder 26 of the punching tool 20 comes into contact with the inner side 16 of the opening of the opening 3, it expands the peripheral metal material in the direction of increasing diameter and is about to be extruded upwards from the opening 3.

[0049] As a result, the metal material at the periphery that was being dragged by the punching tool 20 and was about to move downward in the sliding direction is stopped in place, thus preventing the collapse of the edge and the retraction of the material at the periphery of the opening 3.

[0050] In addition, such as Figure 3 As shown, the metal processing apparatus 1 of this embodiment includes a striking tool 30 for a striking process. The striking tool 30 slides together with a sliding moving body in the vertical direction and strikes the fine protrusions 6 generated around the opening 3 from above to flatten them.

[0051] For example, when punching the opening 3 using the punching tool 20, depending on the insertion amount of the shoulder 26, sometimes as Figure 2 As shown, a fine protrusion 6 protrudes upwards at the periphery of the opening 3.

[0052] The striking tool 30 has a flat striking surface 32 on the lower surface side facing the plate 2.

[0053] The striking surface 32 is arranged parallel to the upper surface 2c of the plate 2 fixed to the clamping fixture, and can evenly strike the fine protrusions 6 generated around the opening 3 by sliding the sliding body downwards, thus making it flat.

[0054] The blanking tool 20 is withdrawn from the opening 3. The fine protrusions 6 formed around the opening 3 are flattened to the same height as the upper surface 2c and become flat by the striking tool 30 striking them from above (see reference). Figure 4 ).

[0055] In this embodiment, such as Figure 5 As shown, 3×4 openings, totaling 12, are formed in a grid pattern on the plate-shaped product 4, with equal horizontal and vertical spacing.

[0056] In the blanking process, such as Figure 6 As shown, the insertion amount of the punching tool 20 into the opening 3 is adjusted by controlling the amount of movement in the sliding direction of each sliding body. Therefore, a device capable of fine-tuning the insertion dimension of the shoulder 26 is preferred. Furthermore, the positional accuracy of the sliding direction of the metal processing device is preferably ±1 / 100 to 1 / 1000 mm. This allows adjustment of the pushing force of the shoulder 26, which abuts against the inner surface 16 of the periphery of the opening 3, to suppress the generation of fine protrusions 6.

[0057] In contrast, Figure 7 This example illustrates a comparative case where an unworked sheet metal was processed using a conventional punching tool with a straight insert and no shoulder 26. In this comparative example, a burr was formed around the periphery of each opening 3a to 3c. The size of this burr (hereinafter also referred to as burr amount d1, d2, etc.) further increases in the areas forming multiple openings 3 (e.g., d1 < d2). Here, the burr amount d1 is approximately 0.1 mm, and d2 is approximately 0.15 mm.

[0058] Especially when the openings 3a to 3c are arranged in a straight line, the collapse amounts d1, d2... formed at the periphery of each opening 3a to 3c accumulate towards the center. Therefore, near the central opening 3b, material recedes downward by a specified dimension H compared to the surrounding upper surface 2c. Here, the specified dimension H is approximately 0.05 mm.

[0059] The effects of the metal processing apparatus and metal processing method described in the embodiments will be explained below.

[0060] In this embodiment, such as Figure 1 As shown, the predetermined opening portion 5 of the plate 2 is forged using a forging tool 10 to work harden it.

[0061] In detail, in the forging process using the forging tool 10 in this embodiment, firstly, the forging tool 10 is mounted on the sliding moving body. The front end 11a of the forging tool 10 is provided in a conical shape tapering at the tip, protruding on the radially central axis S, and is positioned directly above the center of the predetermined opening portion 5.

[0062] By moving the sliding body downwards in the sliding direction, the pressing part 11 moves downwards in a manner similar to the horizontally fixed plate 2. Then, the front end 11a abuts against the center of the predetermined opening portion 5 of the plate 2.

[0063] As the sliding body moves further downward in the sliding direction, the pushing part 11 of the forging tool 10 pushes the metal material away from the radial center abutted by the front end 11a in the outer diameter direction. The pushed-away part 2b has a higher density than the other parts of the plate 2 and thus undergoes work hardening (base material hardening).

[0064] Furthermore, since the pressing part 11 of this embodiment is provided with a conical front end 11a, the metal material that is pressed evenly in any direction from the central axis S to the outer diameter direction is pushed away.

[0065] Furthermore, in this embodiment, the conical pressing portion 11 of the forging tool 10 is designed to taper at its tip. Therefore, at the predetermined opening portion 5, when the metal material is evenly pushed aside, the metal material is compressed downwards towards the pressing portion 11. Additionally, since a greater amount of metal material is evenly pushed aside around the outer diameter, the generation of cracks and the like is suppressed. Thus, it is possible to obtain the predetermined opening portion 5 with a radial dimension c2 that is work-hardened, larger than the outer diameter c1 of the pressing portion 11.

[0066] Furthermore, during the forging process, a recessed portion that causes the upper surface to be recessed may be formed in the clamping fixture that holds the plate 2 in place. More preferably, the recessed portion is formed to align with the central axis S.

[0067] In the forging process using forging tool 10, the flat portion 12 prevents the metal material around the predetermined opening portion 5 from retracting upwards in the outward direction. Therefore, the efficiency of work hardening is good due to further compression.

[0068] like Figure 2 As shown, the insertion part 22 of the blanking tool 20 is inserted into the work-hardened portion of the predetermined opening portion 5 to form the opening portion 3. The blanking tool 20 causes the shoulder 26 to abut against the work-hardened portion remaining on the inner periphery of the opening portion 3 from the inner side 16.

[0069] At this point, by adjusting the insertion depth of the punching tool 20, the force applied by the shoulder 26 to the inner side 16 is stopped just before the micro protrusion 6 is about to protrude upwards beyond the upper surface 2c. As a result, the periphery of the opening 3 is flush with the upper surface 2c, which improves the appearance quality.

[0070] In addition, depending on the insertion amount of the punching tool 20, the resulting fine protrusions 6 protrude upwards from the periphery of the opening 3.

[0071] In this embodiment, such as Figure 3 As shown, use a tapping tool 30 to tap the fine protrusions 6 that protrude from around the opening 3, as... Figure 4 As shown, it can form a flat surface that is flush with the upper surface 2c.

[0072] Therefore, based on the performance of the metal processing apparatus 1, even if the positional accuracy of the sliding direction of the sliding moving body is not high, edge collapse and material retraction can be reduced, and a plate-shaped product 4 with the desired appearance quality can be obtained without increasing manufacturing costs.

[0073] In addition, such as Figure 8 As shown, the expansion ratio (r / h) of the curved surface 28 of the shoulder 26 increases as it moves from the insertion portion 22 on the front end side to the base end portion 24 on the base end side.

[0074] That is, the diameter expansion ratio can be set to be small near the insertion part 22 on the front end side. Therefore, even if the metal processing device 1 is not a metal processing device with high positional accuracy in the sliding direction, the force of the shoulder 26 pressing against the inner surface 16 will not change abruptly. As a result, metal processing devices with lower positional accuracy in the sliding direction of the sliding moving body can be used, for example, metal processing devices with positional accuracy in the sliding direction of about 1 / 10 mm, and the increase in manufacturing cost is suppressed.

[0075] For example, by using a curved surface 28 with an expansion ratio r1 / h1 (or r2 / h2) smaller than the expansion ratio r2 / h2 (or r3 / h3), the change in the machining amount of the opening 3 due to the positional offset of the sliding direction is small.

[0076] Furthermore, the diameter expansion ratio on the base end portion 24 side of the shoulder 26 can be set to be larger than that on the insertion portion 22 side. Therefore, the change in cross-sectional area in the direction orthogonal to the central axis can be reduced at the connection between the shoulder 26 and the base end portion 24, thereby avoiding the portion being set as the starting point of bending. Therefore, the blanking tool 20 can improve the support rigidity of the insertion portion 22, and the machining of fine openings 3 can be easily performed.

[0077] In addition, such as Figure 3 As shown, the striking tool 30 brings the flat striking surface 32 into contact with the opening 3 and strikes the fine protrusions 6 around the opening 3 to flatten them.

[0078] Therefore, even if the positional accuracy of the sliding direction of the sliding body is not high, it can still achieve the same result. Figure 4 As shown, the area around the opening 3 is flush with the other upper surface 2c of the plate 2.

[0079] Therefore, a plate-shaped product 4 with reduced edge collapse and material shrinkage and the desired appearance quality can be obtained.

[0080] Figures 9A to 9CA modified example of the forging tool according to the embodiment is shown. Furthermore, for parts that are the same as or equivalent to the metalworking apparatus and metalworking method of the embodiment, the same reference numerals are used and descriptions are omitted.

[0081] Figure 9A A modified forging tool 40 is shown. The forging tool 40 has a flat end face 41 as a pressing surface. Moreover, the forging tool 40 forges the sheet metal 2 to work harden it.

[0082] Through work hardening, the predetermined opening portion 5 can be pushed open from the radial center toward the outer diameter direction with a larger area than in the embodiment, thereby increasing the density.

[0083] Other structures and effects are omitted from the description as they are the same as or equivalent to the metal processing apparatus and metal processing method described in the embodiments.

[0084] Figure 9B To use a pressing surface 51 with a conical shape tapering to a point at the front end, and to ensure that there are no flat portions around the pressing surface 51 (see reference). Figure 1 The forging tool 50 of the flat section 12) forges the plate 2 to work harden it by forging.

[0085] With the forging tool 50 constructed in this way, the predetermined opening portion 5 can be pushed open from the radial center toward the outer diameter direction, thereby increasing the density.

[0086] Other structures and effects are omitted from the description as they are the same as or equivalent to the metal processing apparatus and metal processing method described in the embodiments.

[0087] Figure 9C A forging tool 60, which has a chamfered inclined surface 62 formed on the outer periphery of the flat end face 61, is used to forge the sheet metal 2 to work harden it.

[0088] With the forging tool 60 constructed in this way, the outer peripheral portion of the predetermined opening 5 can be pushed open from the radial center toward the outer diameter direction, thereby increasing the density.

[0089] Other structures and effects are omitted from the description as they are the same as or equivalent to the metal processing apparatus and metal processing method described in the embodiments.

[0090] As described above, the metal processing method using the metal processing apparatus 1 of this embodiment includes: a forging process in which the predetermined opening portion 5 of the sheet metal 2 is work-hardened by forging (see reference). Figure 1 ); and the punching process of forming the opening 3 by punching at the predetermined opening portion 5 of the forged plate 2 (see reference). Figure 2 ).

[0091] Therefore, the predetermined opening portion 5, which has undergone work hardening in the forging process, is punched in the blanking process to form the opening portion 3.

[0092] The metal material around the opening 3 is pushed outward from the radial center towards the outer diameter, thereby increasing its density. Therefore, it is possible to reduce edge collapse and material retraction around the opening 3.

[0093] In addition, the tapping process (see Figure 3 The micro-protrusions 6 generated around the punched opening 3 are flattened by striking the punching tool 30. Therefore, even if micro-protrusions 6 are generated during the punching process due to poor accuracy of the movement of the punching tool 20 in the sliding direction, they can be flattened by striking the micro-protrusions 6 with other upper surfaces 2c.

[0094] Thus, in the metal processing apparatus and metal processing method of this embodiment, edge collapse and material shrinkage can be reduced, and the appearance quality of the plate-shaped product 4 can be improved.

[0095] This invention is not limited to the embodiments described above, and various modifications are possible. The embodiments described above are illustrative for ease of understanding and are not necessarily limited to all the structures described. Furthermore, a portion of the structure of one embodiment can be replaced with the structure of another embodiment, and a structure of another embodiment can be added to the structure of one embodiment. Additionally, a portion of the structure of each embodiment can be deleted, or other structures can be added or replaced. Examples of modifications possible with the above embodiments are as follows.

[0096] In this embodiment, such as Figures 9A to 9C As shown, three variations of forging tools are illustrated, but the forging tools, punching tools, and striking tools are not limited to the tools of this embodiment. For example, the front end may also be hemispherical or the like. As long as the predetermined opening portion is work-hardened by forging, the shape, number, and material of the forging tools, punching tools, and striking tools are not particularly limited.

[0097] Explanation of reference numerals in the attached figures

[0098] 1 Metalworking equipment

[0099] 3. Opening

[0100] 5. Pre-determined opening location

[0101] 10 Forging Tools

[0102] 16. Inner side

[0103] 20. Cutting tools

[0104] 22 Insertion section

[0105] 24. Base end

[0106] 26. Shoulders.

Claims

1. A metal working apparatus characterized by comprising: Possessing: a forging tool that work-hardens an opening scheduled site of a workpiece by forging; and a blanking tool that forms an opening portion at the opening scheduled site, the blanking tool has an insertion portion of the same diameter as the opening portion and a shoulder portion that is continuously provided with the insertion portion and that expands in diameter toward the base end side of the blanking tool, when the opening portion is formed by blanking, the blanking tool is inserted to a position where the work-hardened site remaining on the inner periphery of the opening portion abuts against the inner side surface of the shoulder portion, and by adjusting the amount of insertion of the blanking tool, the force applied to the inner side surface from the shoulder portion is stopped before the fine protrusion at the periphery of the opening portion protrudes upward more than the upper surface of the workpiece.

2. The metal working apparatus according to claim 1, wherein the forging tool is provided with a push portion that pushes the opening scheduled site outward from the radial center.

3. The metal working apparatus according to claim 2, wherein the push portion is a conical shape with a tapered tip.

4. The metal working apparatus according to claim 2, wherein a flat portion that abuts against the periphery of the opening scheduled site at the time of forging is provided around the push portion.

5. The metal working apparatus according to claim 1, wherein the shoulder portion of the blanking tool has a curved surface with an expansion rate that increases toward the base end side.

6. The metal working apparatus according to claim 1, comprising: a tapping tool that taps the periphery of the opening portion to flatten it in a state where the opening portion is formed by blanking, the tapping tool has a tapping surface that taps the fine protrusion at the periphery of the opening portion that is generated by the insertion of the shoulder portion of the blanking tool to flatten it.

7. A metal working method characterized by, Possessing: a forging step that work-hardens an opening scheduled site of a workpiece by forging; and a blanking step that forms an opening portion at the forged opening scheduled site of the workpiece, in the blanking step, by adjusting the amount of insertion of the blanking tool, the force applied to the inner side surface from the shoulder portion of the blanking tool is stopped before the fine protrusion at the periphery of the opening portion protrudes upward more than the upper surface of the workpiece.

8. The metal working method according to claim 7, further comprising: a tapping step that taps the fine protrusion at the periphery of the formed opening portion to flatten it by a tapping tool.

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