JP2022515265A - Multi-layer precision punching process for manufacturing metal parts and precision punching equipment for performing such processes - Google Patents

Abstract

The present invention relates to a process for simultaneously punching metal parts from a multi-layered basic material (51) composed of mutually stacked, preferably essentially identical individual layers (50). Prior to such punching of metal parts, the multilayer basic material (51) is connected between the press lock punch (101) and the anvil (103) by local plastic deformation of the multilayer basic material (51). (1) is provided so that the individual layers (50) are fixed to each other in all three spatial dimensions. According to the present invention, the connecting portion (1) is provided on the multilayer basic material (51) outside the (virtual) contour of the metal part (10) to be punched.

Description

The present disclosure relates to a process for punching metal parts, in particular a multi-layer precision punching process. The precision punching process itself is generally known and is widely applied in the manufacture of metal parts, especially for cutting metal parts from basic materials in strip or plate shape. In a known precision punching process, at least a two-dimensional contour of a metal part is formed by pressing a punching punch of the corresponding shape against the base material and penetrating it, which base material is used with the punching die and blank holder of the punching device. It is clamped in between. The punching die and its blank holder define each cavity shaped to accommodate the punching punch. The edges of the punching die, which demarcate the cavity of the punching die, carve into the basic material as such basic material is gradually pushed into the cavity by the movement of the punching punch relative to the punching die, and eventually completely. Cut through. The precision punching process is more distinguished from the conventional punching process in that it has a counter punch located opposite the punching punch and the counter punch pushes the opposite side of the punching punch of the basic material.

In order to increase the production rate of the former known punching process, the art applies to layered basic materials, i.e., two or more layers of basic material prior to actual punching, i.e. cutting of the basic material. It is proposed to stack each other. In this case, a plurality of metal parts corresponding to the number of layers of the layered basic material can be formed by one punching stroke using a single punching punch. Japanese Patent Application Laid-Open No. 57-156657 teaches an early example of such a multi-layer punching process, particularly the conventional modification that does not include a counter punch for precision punching. According to this document, a three-layer stack consisting, in particular, two metal strips and a third strip of insulating material sandwiched between them is supplied to the punching device, followed by two mutually insulated. Rotor parts are simultaneously punched from such layered basic material by punching punches. Further, Japanese Patent Application Laid-Open No. 57-156657 teaches that the layered basic material is provided with protrusions protruding through all three layers of the layered basic material in a direction perpendicular to the length direction of the strip. These known protrusions are provided to prevent the individual layers of the layered basic material from sliding relative to each other as the layered basic material advances intermittently within the punching device during each punching stroke. There is. In particular, each such known protrusion is formed by bending the edge area of the layered strip downward, which is defined between two relatively close cuts into the side edges of the layered strip. To.

The multi-layer punching process is particularly relevant for the production of relatively thin thickness metal parts, such as individual thin plates for electric motor stator laminates or rotor laminates, by using such thin thickness basic materials. do. In particular, the application of such a layered basic material can increase the production rate of the punching process, which is essentially proportional to the number of layers applied to the layered basic material. A variant of the multi-layer precision punching process for multi-layer punching has recently been released internationally to handle thinner metal parts, i.e., to handle thinner layers of basic material than are possible with conventional punching processes. It is proposed in No. 2017/174215.

According to the present disclosure, known layered basic materials can be improved in view of their application in multi-layer precision punching processes. In particular, according to the present disclosure, known protrusions of layered basic materials may not function well in precision punching processes, as in conventional punching processes.

The present disclosure deviates from the insight that known projections provide connections within the plane of their main planes of stacked layers, ie strips of layered basic material, but not perpendicular to that plane. And it depends on it. In other words, the known protrusions prevent the individual layers of the layered base material from sliding each other in their length and width directions, but separate the individual layers in their height, i.e., thickness direction. There is no prevention. Further, the present disclosure is a particular feature of the precision punching process, i.e., after a metal part has been cut by a punching punch, the layered base material and punching die create a gap between the layered base material and the punching die. Consider that the metal parts are then moved apart for this gap and then removed from the precision punching device. In particular, due to such movement of the layered basic material with respect to the punching die, the layered basic material is no longer supported in its height direction, and typically by said intermittent advancement of the layered basic material, for example, the layered basic material. Vibration also occurs in the material in its height direction. As a result, the mutual alignment of the individual layers of the layered base material may not be optimally maintained as a result.

According to the present disclosure, a layered basic material is locally plastically deformed to create a connection between the individual layers of the layered basic material in all of its length, width, and height directions. This is done prior to the area of the layered basic material having such a connection being advanced between the punching die and the blank holder or between the punching punch and the counter punch of the precision punching device. The connection is formed outside the virtual contour of the metal part to be punched from the base material, which degrades the mechanical and / or electrical properties of these metal parts due to the plastic deformation associated with the press lock. There is an advantage of not doing it. Further, in this case, the coating provided on each layer of the layered basic material, such as an electrically insulating coating, is retained intact at the position of the metal part. These latter aspects of the present disclosure are particularly relevant to the stator and rotor lamellae of electric motors.

It should be noted that such a method of connecting by plastic deformation itself is generally known to be for connecting two sheet metal layers in all three dimensions, and is hereinafter referred to as press lock. In the art, such press-locking methods and / or variants thereof are also referred to as clinching. Due to the excessive (plastic) deformation that would be required for that known application, press locking of more than two sheet metal layers is not performed. However, according to the present disclosure, in certain situations of multi-layer precision punching, press locks have surprisingly been found to be suitable for joining and connecting three or more layers of sheet metal. , That is, these layers have a total thickness in the range of 0.2 mm to 1.2 mm, and their individual thicknesses are in the range of 0.1 mm to 0.3 mm, preferably 0. This is the case when it does not exceed 2 mm.

Known press-lock methods are press-lock punches and anvils located on opposite sides of the layered base material, and the layered base material between them is plastically deformed into a keyed connection, referred to herein as a connection. Requires press lock punches and anvils that are pressed together to allow. In combination with the known multi-layer precision punching process, the known press-locking method has the advantage that the movement of the press-lock punch with respect to the anvil can be advantageously harmonized with the movement of the blank holder or punching punch with respect to the punching die, i.e. opening and closing the punching device. Has. Preferably, these relative movements are not only harmonized with each other, but also triggered together. In other words, the press joint can be advantageously integrated into the multi-layer precision punching process and thus the novel multi-layer precision punching process according to the present disclosure can be carried out.

Further, according to the present disclosure, a plurality of simultaneously actuated press-lock punches and anvil pairs are used to simultaneously create a plurality of connections. This has the advantage that the connection of the individual layers of the layered basic material is more stable without compromising the production rate of the punching process and / or punching equipment.

The multilayer precision punching process and apparatus according to the present disclosure will be further described below with reference to the drawings by way of exemplary embodiments.
It is a schematic plan view of a typical punched metal part, the punched metal part is a single sheet made of electrical steel for a stack of sheets for a rotor of an electric motor, i.e. for a laminate. It is a schematic diagram illustrating a multi-layer punching device and a process for forming a metal part. It is a schematic diagram illustrating a multi-layer punching device and a process for forming a metal part. It is a schematic diagram illustrating a multi-layer punching device and a process for forming a metal part. It is a schematic diagram illustrating a multi-layer punching device and a process for forming a metal part. It is a schematic diagram illustrating a multi-layer punching device and a process for forming a metal part. It is a schematic diagram illustrating a multi-layer punching device and a process for forming a metal part. It is sectional drawing which outlines the layered basic material used in a multi-layer punching process, and this layered basic material is provided with the connecting part between the individual layers thereof. It is a schematic diagram illustrating a simplified press lock device and process for connecting individual layers of a layered basic material. It is a schematic diagram illustrating a simplified press lock device and process for connecting individual layers of a layered basic material. FIG. 6 is a perspective view schematically depicting an alternative embodiment of a connection between individual layers of a layered basic material. It is a schematic representative diagram of a new multi-layer punching process including a press lock process step.

FIG. 1 provides an example of a metal part 10 that can be successfully produced using a punching process, in particular the multi-layer punching process discussed herein. In this example, the metal component 10 takes the form of an individual rotor disk 11 for a rotor laminate, i.e., a stack of rotor disks for an electric motor. In this particular example, the rotor disk 11 is provided with a primary hole or a central hole 12, and a plurality of secondary holes 13 arranged along the perimeter of the rotor disk 11. The outer contour of the rotor disk 11, i.e. the boundary, and the contour of the central hole 12 and the secondary hole 13 of the rotor disk 11 are formed, i.e., from the basic material, especially the electrical steel, at the same time in one cut, i.e. the punching device 90. It is cut out with a single stroke of, or with multiple partial cuts performed sequentially at different stages of the punching process. In the electric motor, the central hole 12 of the rotor disk 11 (stack) accommodates the rotor shaft, and the secondary hole 13 of the rotor disk 11 (stack) accommodates the magnet. In many cases, in order to reduce so-called eddy current loss, an electrically insulating layer is provided between the individual rotor disks 11 in the rotor stack, and this electrically insulating layer may be used for the rotor disk 11 before punching. It is a form of an electrically insulating coating applied to at least one side of the basic material of.

It should be noted that the exact size or contour of the rotor disk 11 illustrated in FIG. 1 is irrelevant within the context of the present disclosure. Rather, the present disclosure is applicable not only to rotor disks 11 of different shapes, but also to the stator ring components (not shown) of the stator laminates of electric motors, and further in the multi-layer precision punching process described below. As long as the component 11 is at least partially formed, it can also be applied to a general metal component 10.

2A-2F are schematic views illustrating a multi-layer punching process for producing a rotor disk 11 or a typical metal component 10. FIGS. 2A-2F are used to cut out such a metal component 10 from two or more (here, four) stacked layers, i.e., a layered basic material 51 with a strip 50 of the basic material, respectively. Represents a simplified cross section of the punching device 90. The punching device 90 includes a punching punch 30, a counter punch 40, a blank holder 70, and a punching die 80. The blank holder 70 and the punching die 80 define the respective cavities 71 or 81, respectively, and the punching punch 30 is housed in the cavity 71, the counter punch 40 is housed in the cavity 81, and these cavities 71 and 81 are metal parts. It is shaped to correspond to 10 (contour). This particular type of punching process / punching device 90 using the counter punch 40 is known as itself, ie precision punching.

In FIG. 2A, the punching device 90 is shown in the first open state, in which the punching punch 30 is completely retracted into the blank holder 70, the counter punch 40 is completely retracted into the punching die 80, and the blank. The holder 70 and the punching die 80 are used to insert and / or advance the layered basic material 51 with respect to the punching device 90 along the length direction of the layered basic material 51, as schematically indicated by the dashed arrow. They are separated from each other, at least enough.

FIG. 2B shows a punching device 90 after the blank holder 70 and the punching die 80 are moved toward each other and the layered basic material 51 is clamped between the blank holder 70 and the punching die 80. ..

FIG. 2C shows a punching device 90 after the punching punch 30 and the counter punch 40 are moved toward each other and the layered basic material 51 is clamped between the punching punch 30 and the counter punch 40. ..

In FIGS. 2D and 2E, a step of cutting out a metal component 10 from each strip 50 of a layered basic material 51 by a forced relative motion of a combination of punching punches 30 and counter punches 40 with respect to a punching die 80 is illustrated. In particular, FIG. 2D shows the punching device 90 during such cutting, and FIG. 2E shows the punching device 90 after the metal component 10 has been completely cut out, that is, after being separated from the layered basic material 51. As shown, these metal parts 10 remain held between the punching punch 30 and the counter punch 40.

In FIG. 2F, the punching device 90 is shown in the second open state, in which the punching punch 30 is completely retracted into the blank holder 70 and the counter punch 40 is the punched metal. After the component 10 is extruded upward from the cavity 81 of the punching die 80, it protrudes from the punching die 80, which enables the metal component 10 to be taken out from the punching device 90. After such removal, the punching device 90 returns to its first open state, as shown in FIG. 2A and the like.

As illustrated in FIG. 2F, in the second open state of the punching device 90, however, even in the first open state, the individual strips 50 of the layered basic material 51 are in their thickness direction. That is, the layered basic material 51 tends to separate from each other in the height direction H. As a result, the mutual alignment of the individual strips 50 in their length and width directions can be compromised, or at least for the punching device, the layered base material 51 is lifted from and / or punched from the punching die 80. Additional means (not shown) must be equipped to support and guide the layered base material 51 as it is advanced relative to the die 80. Further, in the second open state of the punching device 90, and as illustrated by the solid arrow in FIG. 2F, the punched metal parts 10 are taken out individually or at least individually, ie as loose parts. Is done.

According to the present disclosure, the former multi-layer punching process can be improved. In particular, synchronization and realignment of the individual strips 50 of the layered base material 51 is local to the strips 50 before the layered base material 51 is inserted between the punching punch 30 and the counter punch 40 of the punching device 90. By creating a connection 1 between the strips 50 by plastic deformation, ie by so-called press lock, these strips 50 are placed in all of their length, width, and thickness directions (ie, three spatial /). It can be advantageously realized by interconnecting (in all physical dimensions).

A possible embodiment of such a connecting portion 1 is schematically illustrated in FIG. 3 in an enlarged cross-sectional view of the layered basic material 51. In this example of the connection, the connection 1 is formed as a dovetail-shaped joint 3 that is essentially circularly symmetric, so that the connection 1 prevents the strip 50 from moving relative to each other in all three dimensions. ..

4A and 4B schematically illustrate examples of press-locking methods, in particular the press-locking method for forming the connecting portion 1 of FIG. In the first step of this particular press-locking method (shown in FIG. 4A), the layered basic material 51 is inserted between the press-lock punch 101 having the protrusions 102 and the anvil 103 defining the recesses 104. To. In the second step of the press lock method (shown in FIG. 4B), the protrusion 102 of the press lock punch 101 is pushed into the layered basic material 51, whereby the recess 2 is formed in the layered basic material 51 (FIG. 3). The basic material 51 is displaced downward into the recess 104 of the anvil 103, thereby not only forming a protruding overhang 4 in the layered basic material 51 (see FIG. 3). It is also displaced laterally, thereby forming the dovetail-shaped joint 3.

In particular, it should be noted that the exact realization of the press-lock method is irrelevant within the context of this disclosure. Rather, the present disclosure provides any press that provides interconnection of the individual layers / strips 50 of the layered base material 51 in all three dimensions by targeted, i.e., local and controlled plastic deformation of the layered base material 51. Also related to the locking method. For example, a press-lock method utilizing a planar anvil is also known, in which the ring is placed around the press-lock punch with some radial clearance. In this realization of the press-lock method, in the second step thereof, the basic material 51 plastically flows laterally and upward between the press-lock punch and the ring, and between the press-lock punch and the ring. Form an annular overhang. It is also known that in a further process step of the press lock method, the overhanging portion 4 of the connecting portion 1 is removed by compressing the layered basic material 51 between the two flat surfaces at the position of the overhanging portion 4. ing. Further, the connecting portion 1 does not need to be formed in a circular symmetry, and may be formed mainly in an elliptical shape, a square shape, or a rectangular shape, for example. In particular, in the case of the rectangular connecting portion 1, the rectangular overhanging portion 4 is formed by bending the short side 6 while shearing the long side 5. In FIG. 5, such a rectangular connecting portion 1 is schematically illustrated in its cross-sectional view. In this realization of the connecting part 1, the relative movement of the individual layers 50; 50-T, 50-B in their thickness direction is the sheared length of the overhanging part 4 at the upper layer 50-T of the layered basic material 51. The side 5 is blocked by capturing the sheared long side 5 of the lower layer 50-B of the layered base material 51. In FIG. 5, the layered basic material is illustrated with two separate layers / strips 50-T, 50-B, the rectangular connecting portion 1 exemplified being three or more layers / strips 50. Suitable for joining.

Preferably, the press lock method described above is performed as part of a multi-layer precision punching process, i.e., as a process stage of a multi-layer precision punching process. In this case, the first press-lock step (FIG. 4A) is synchronized with the first multilayer precision punching step (FIG. 2A), whereas the second press-lock step (FIG. 4B) is preferably layered. Synchronized with the cutting out of the metal part 10 from the basic material 51 (FIG. 2D). Such a novel multi-layer punching process, including a press lock, is schematically illustrated in FIG. 6 in connection with the rotor disk 11 exemplified in FIG.

As illustrated in FIG. 6 in the plan view of the layered basic material 51, that is, when viewed downward in the height direction H of the layered basic material 51, the two connecting portions 1 (1a, 1b) are new multilayers. It is provided on the layered basic material 51 at the press lock stage of the punching process. Once formed, the connecting portion 1 is transferred to the punching stage together with the layered basic material 51 by the intermittent advancement of the layered basic material 51. In this punching stage, the metal part 10 (illustrated as the rotor disk 11 in FIG. 6) is entirely cut from the layered basic material 51 in one complete cut (not shown) or of the metal part 10. It is cut out by partial cutting performed two or more times in sequence depending on the complexity (of the contour). In particular, as illustrated in FIG. 6, in the first partial cut, the central hole 12 and the secondary hole 13 of the rotor disk 11 are formed, and then in the second partial cut, the rotor disk An outer circumference 14 is formed, whereby the rotor disk 11 is separated from the layered basic material 51, leaving a space 15 in the layered basic material 51. During these first and second partial cuts, between the first partial cut and the second partial cut, and after the first and second partial cuts, the layered basic material 51 The individual layers 50 of the above are advantageously held together together by the connecting portion 1. According to the present disclosure, the connecting portion 1 is formed on the outside of the outer circumference 14 of the metal component 10, and therefore, advantageously, the metal component 10 remains unaffected by the connecting portion 1.

The present disclosure relates to and includes all features of the appended claims, in addition to the whole of the above description and all the details of the accompanying drawings. The parenthesized references in the claims are not limiting in scope and each reference is provided as a non-binding example of the respective features. The separately claimed features may, in some cases, be applied separately to a particular product or a particular process, but it is also possible to apply any combination of two or more of such features at the same time.

The inventions represented by the present disclosure are not limited to the embodiments and / or examples expressly referred to herein, and those which can be conceived by those skilled in the art in particular. Also includes direct improvements, corrections, and practical applications of.

Claims (9)

A method for punching a metal part (10; 11) from a layered basic material (51) by a punching device (90), and each of the punching devices (90) has a blank holder defining a cavity (71; 81). (70) and a punching die (80) are provided, and the cavity (71; 81) is formed by using a punching punch (30) and a counter punch (40) housed in the cavity (71; 81). It has a circumferential shape corresponding to the circumferential shape of the metal part (10; 11) to be punched, on the one hand the blank holder (70) and the punching die (80), and on the other hand the punching punch (30). ) And the counter punch (40) are both movable with respect to each other and relative to each other, and the layered basic material (51) is, on the one hand, with the blank holder (70) and the punching die (80). On the other hand, the punched punch (30) is clamped between the punched punch (30) and the counter punch (40), and then the punched punch (30) is supported by the counter punch (40). Is moved through a series of layers (50) of the layered basic material (51), thereby enclosing a plurality of the metal parts (10; 11) from the basic material (51) to a single metal. In a method for punching a metal part (10; 11) from a layered basic material (51), which separates the parts (10; 11) into layers (50).
Prior to separating the metal part (10; 11), the layer (50) of the layered basic material (51) is the outer circumference of the metal part (10; 11) to be cut, ie, the contour (14). ) From the layered basic material (51) to the metal part (10; 11) A method for punching out. The layer (50) of the layered basic material (51) is characterized in that it has at least substantially equal thicknesses from each other, at least shares substantially the same material composition, or both. The method for punching a metal part (10; 11) from a layered basic material (51) according to claim 1. The layered basic material (51) comprises at least three layers (50) having a layer thickness of up to 0.3 mm and having a total thickness of the layered basic material (51) up to 1.2 mm. The method for punching a metal part (10; 11) from a layered basic material (51) according to claim 1 or 2. The metal from the layered basic material (51) according to claim 1 or 2, wherein the layer (50) of the layered basic material (51) is provided with a coating, particularly an electrically insulating coating. A method for punching out a part (10; 11). The one according to any one of claims 1 to 4, wherein each of the one or a plurality of the connecting portions (1) is provided with at least one recess (2) in the layered basic material (51). , A method for punching a metal part (10; 11) from a layered basic material (51). The blank holder (70) of the punching device (90) has at least one inserted into the at least one recess (2) of the connecting portion (1) during the separation of the metal component (10; 11). The method for punching a metal part (10; 11) from a layered basic material (51) according to claim 5, wherein one pin is provided. Each of the one or more connecting portions (1) comprises a substantially rectangular overhanging portion (4) of the layered basic material (51), wherein the overhanging portion (4) is a separated long side. It has (5) and a bent short side (6), and the width between the cut long sides (5) is the dimension of the recess (2) of each of the connecting portions (1) in the width direction. The method for punching a metal part (10; 11) from a layered basic material (51) according to claim 5 or 6, characterized in that it is larger than. The punching device (90) is provided with a blank holder (70) and a punching die (80) defining a cavity (71; 81), respectively, and the cavity (71; 81) is the cavity (71; 81; It has a circumferential shape corresponding to the circumferential shape of the metal part (10; 11) to be punched by using the punching punch (30) and the counter punch (40) housed in 81), while the blank holder (1). In the punching device (90), the punching die (80) and the punching die (80), on the other hand, the punching punch (30) and the counter punch (40) are both movable with respect to each other and relative to each other. ,
The punching device (90) is further provided with a press lock punch (101) that defines a protrusion (102) and an anvil (103) that is arranged to face each other and defines a recess (104). A punching device (90), characterized in that the punch (101) and the anvil (103) are mutually movable. The movement of the press lock punch (101) relative to the anvil (103) is the movement of the punch punch (30) or the movement of the blank holder (70) relative to the punch die (80). The punching device (90) according to claim 8, characterized in that it is associated with movement.

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