Punching jig and method

Abstract

Provided is a blanking jig capable of blanking taking into account roundness and capable of being easily adjusted to a target shape at the time of manufacture, maintenance, and the like of the blanking jig. A blanking jig (1) forms a member (3) having a circular blanking portion from a steel sheet (W), wherein a punch (5) and a die (7) into which the punch (5) enters to enable blanking of the member (3) are provided, and at least one of an outer shape of the punch (5) and an inner shape of the die (7) is a different diameter shape having two or more right circular arc portions (9) and right circular arc portions (11) having different radii of curvature.

Description

Technical Field

[0001] This invention relates to a punching fixture and method for punching out components with circular punched portions, such as ferrite chips for use in rotary electric motors and laminated iron cores. Background Technology

[0002] As with conventional blanking fixtures, such as Patent Document 1, it was found that the roundness of the iron chip blanking produced by a perfectly round die is determined by the elongation of the steel plate, and a blanking fixture was disclosed that makes the iron chip perfectly round by adjusting the roundness of the die.

[0003] However, for dies that require roundness adjustment, roundness adjustment needs to be performed simultaneously at multiple locations during fixture fabrication and maintenance. Therefore, in conventional blanking fixtures, there is a problem that time and effort are spent on adjusting the fixture to the target shape during fixture fabrication and maintenance.

[0004] Such problems arise extensively when parts with circular die-cut portions are produced.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 10-24333 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The problem to be solved is that, when roundness is taken into account in the blanking process, it takes effort to adjust the shape of the blanking fixture.

[0010] Solution for solving the problem

[0011] The present invention provides a blanking fixture for blanking parts having circular blanking portions from steel plates. The fixture includes: a punch; and a die into which the punch enters to perform blanking of the part. At least one of the external shape of the punch and the internal shape of the die is a unequal-diameter shape having two or more circular arc portions with different radii of curvature.

[0012] The present invention provides a punching method for punching out a component having a circular punched portion from a steel plate. In this method, the circumferential positions of two or more circular arc portions with different radii of curvature are set according to the anisotropy of the steel plate, on at least one of the external shape of the punch and the internal shape of the die. The punch enters the die and the component is punched out from the steel plate between the punch and the die.

[0013] Invention Effects

[0014] The present invention enables punching that takes roundness into account and allows for easy adjustment of the shape of the punching fixture. Attached Figure Description

[0015] Figure 1 This is a schematic cross-sectional view of the punching fixture of Embodiment 1 of the present invention.

[0016] Figure 2 It is Figure 1 The top view shows the overlapping of the die and punch of the blanking fixture.

[0017] Figure 3 This is a top view showing the iron core of the stator core and the rotor core.

[0018] Figure 4 This is a top view of an iron chip, illustrating an example of the anisotropy of a steel plate.

[0019] Figure 5 This is a top view showing the internal shape of the die and the external shape of the punch of the blanking fixture in the modified example of Embodiment 1.

[0020] Figure 6 This is a top view showing the internal shape of the die and the external shape of the punch of the blanking fixture in other variations of Embodiment 1.

[0021] Figure 7 This is a top view showing the internal shape of the die and the external shape of the punch of another variation of the blanking fixture in Embodiment 1.

[0022] Figure 8 This is a top view showing the internal shape of the die and the external shape of the punch of another variation of the blanking fixture in Embodiment 1.

[0023] Figure 9 This is a top view of a steel plate showing another variation of Embodiment 1.

[0024] Figure 10 This is a top view showing the internal shape of the die and the external shape of the punch of the blanking fixture of Embodiment 2 of the present invention superimposed.

[0025] Figure 11 This is a top view showing the internal shape of the die and the external shape of the punch of the blanking fixture in the modified example of Embodiment 2.

[0026] Figure 12 This is a top view showing the internal shape of the die and the external shape of the punch of the blanking fixture of Embodiment 3 of the present invention superimposed. Detailed Implementation

[0027] In one embodiment, a blanking fixture 1 cuts out a component 3 having a circular blanking portion from a steel plate W. The blanking fixture 1 includes a punch 5 and a die 7 into which the punch 5 enters to perform blanking of the component 3. At least one of the external shape of the punch 5 and the internal shape of the die 7 is a non-circular shape having two or more circular arc portions 9, 11, 15, 17, 21, 23 with different radii of curvature.

[0028] The external shape of punch 5 and the internal shape of die 7 can be arbitrarily set according to the anisotropy of steel plate W.

[0029] In one embodiment, one of the external shape of the punch 5 and the internal shape of the die 7 can be made into different diameters, and the other of the external shape of the punch 5 and the internal shape of the die 7 can be made into a single perfect circle.

[0030] As another implementation, the external shape of the punch 5 and the internal shape of the die 7 can both be made to have different diameters.

[0031] Two or more circular arc portions 9, 11, 21 and circular arc portions 15, 17, 23 can be configured in a concentric shape.

[0032] The adjacent circular arc portions 9, 11, 21 and 15, 17, 23 in the circumferential direction can also be continuous in the circumferential direction via non-circular arc portions 13, 19.

[0033] In the blanking method, based on the anisotropy of the steel plate W, the circumferential positions of two or more circular arc portions 9, 11, 15, 17, 21, 23 with different radii of curvature are set on at least one of the external shape of the punch 5 and the internal shape of the die 7, so that the punch 5 enters the die 7 and the part 3 is blanked out from the steel plate W between the punch 5 and the die 7.

[0034] The steel plate W can be set in a way that the transverse bending direction is a predetermined direction, and the component 3 can be punched out from the steel plate W.

[0035] Example 1

[0036] [Punching Fixture]

[0037] Figure 1 This is a schematic cross-sectional view of the punching fixture of Embodiment 1 of the present invention. Figure 2 It is Figure 1 The top view shows the overlapping of the die and punch of the blanking fixture. Figure 3 This is a top view showing the iron core of the stator core and the rotor core.

[0038] Figure 1The blanking fixture 1 is a blanking fixture for cutting iron blanks 3, which are components with circular blanking portions, from steel plates W. The iron blanks 3 are used for the laminated iron cores of rotating electric motors. The laminated iron cores can be either stator cores or rotor cores. It should be noted that the component with the circular blanking portion is not limited to the iron blank 3; any component with a circular external or internal shape is acceptable.

[0039] In this embodiment, Figure 3 The iron chip 3A of (A) is the iron chip of the stator core, which is a ring-shaped plate with a circular internal and external shape of the stamped part. Figure 3 The iron chip 3B of (B) is the iron chip of the rotor core, which is a ring-shaped plate with a circular internal and external shape and a central hole 6.

[0040] It should be noted that, in Figure 3 In (A) and (B), only the approximate shapes of iron chip 3A and iron chip 3B are shown. The circular inner shape of the stator core iron chip 3A is the shape of the imaginary circle where the front end of the tooth 4 is located. In the following description, for ease of explanation, iron chip 3A and iron chip 3B will be collectively referred to as iron chip 3. In addition, unless specifically required, the circular inner and outer shapes of iron chip 3A and the circular inner and outer shapes of iron chip 3B will be referred to as the punched portion.

[0041] In this embodiment, the blanking fixture 1 is a blanking fixture for forming the iron chip 3 from the steel plate W, which reduces (increases) the roundness of the blanked portion of the iron chip 3. In the case of the external shape of the iron chip 3, roundness refers to half the difference between the maximum and minimum outer diameters. Similarly, the roundness of the internal shape of the iron chip 3 refers to half the difference between the maximum and minimum inner diameters.

[0042] The blanking fixture 1 includes a punch 5 and a die 7. The punch 5 is used by mounting an upper die, etc., and the die 7 is used by mounting a lower die, etc. By bringing the punch 5 and the die 7 relatively close together, the punch 5 enters the hole 7a of the die 7, and the blanking of the iron chip 3 can be performed. The blanking of the iron chip 3 here refers to the blanking of the internal and external shapes of the iron chip 3A and the external shape of the iron chip 3B.

[0043] At least one of the external shape of the punch 5 and the internal shape of the die 7 is a non-circular shape with two or more circular arc portions 9 and 11 having different radii of curvature within the range where the punch 5 enters the hole 7a of the die 7. In this embodiment, the internal shape of the die 7 is a non-circular shape with two circular arc portions 9 and 11. Circular arc portions 9 and 11 refer to arc-shaped portions that are part of a perfect circle. A perfect circle refers to a circle having the roundness required for the iron chip 3 in this embodiment.

[0044] The number, position, diameter, and center position of the circular arcs are determined based on the anisotropy of the steel plate W. The anisotropy of the steel plate W refers to the property and direction of the blank 3 as it extends relative to the circle when the external shape of the punch 5 and the internal shape of the die 7 are punched into a circle, with regard to the blank 3. Figure 4 An example of anisotropy is shown. In Figure 4 In the middle, the punched iron chip 3 is conveyed along the steel plate W in the direction of transport ( Figure 1 , Figure 2 as well as Figure 4 (Extends in the left and right directions).

[0045] Accordingly, in this embodiment, as described above, two types of circular arc portions 9 and 11 are provided in the die 7. Specifically, the smaller-diameter circular arc portion 9 is located on both sides of the hole portion 7a of the die 7 in the conveying direction of the steel plate W, and the larger-diameter circular arc portion 11 is located in the width direction of the steel plate W, which is orthogonal to the conveying direction. Figure 1 orthogonal direction of the paper Figure 2 and Figure 4 The two sides of the hole 7a of the punch 7 in the vertical direction.

[0046] The two circular arc portions 9 and 11 are arranged concentrically, but they can also be offset from each other. The circular arc portions 9 and 11 adjacent in the circumferential direction are continuous in the circumferential direction via a non-circular arc portion 13. The non-circular arc portion 13 refers to a straight or curved portion that is not part of a perfect circle. In this embodiment, the non-circular arc portion 13 is a straight portion along the radial direction. It should be noted that the non-circular arc portion 13 is preferably arranged in a centrally symmetrical manner.

[0047] [Cutting methods, etc.]

[0048] In the blanking method of this embodiment, the positions of the circular arc portions 9 and 11 in the circumferential direction of the inner diameter of the die 7 are first set according to the anisotropy of the steel plate W. The anisotropy of the steel plate W can be confirmed by blanking the steel plate W with the external shape of the punch 5 and the internal shape of the die 7 set to perfect circles in advance. Then, the circular arc portions 9 and 11 of the die 7 are formed at the circumferential positions corresponding to the anisotropy. However, the circumferential positions of the already formed circular arc portions 9 and 11 of the die 7 can also be adjusted by rotation or the like.

[0049] With this setting, for example, the circular arc portions 9 and 11... Figure 2 In this case, it is located on both sides of the conveying direction and on both sides of the width direction. However, depending on the anisotropy of the steel plate W, the circular arc portion 9 may not be located in the conveying direction, but on both sides in a direction inclined relative to the conveying direction. Correspondingly, the circular arc portion 11 may not be located in the width direction, but on both sides in a direction inclined relative to the width direction.

[0050] With the circular arc portions 9 and 11 set as described, the iron chip 3 is punched out from the steel plate W. That is, the punch 5 descends and enters the die 7, thereby punching out the punched portion of the iron chip 3 from the steel plate W between the die 7 and the punch 5. As described above, the punching of the iron chip 3 is performed relative to the internal or external shape in the case of the stator core, and relative to both the internal and external shapes in the case of the rotor core.

[0051] The roundness of the punched portion of the iron chip 3 is improved by suppressing elongation deviation. For example, the punched portion of the iron chip 3 suppresses the elongation at the point where the gap between the punch 5 and the die 7 becomes smaller, thereby improving the roundness of both the internal and external shapes of the iron chip 3. It should be noted that the improvement in roundness is given as an example based on the gap, but it can be achieved by suppressing and promoting elongation locally, based on the external shape of the punch 5 and the internal shape of the die 7.

[0052] The external shape of the punch 5 and the internal shape of the die 7 are respectively composed of a single perfect circle and a shape with different diameters formed by the arcs 9 and 11 of the perfect circle. Therefore, the shape is simple and can be easily adjusted to the target shape by grinding during fixture manufacturing and maintenance.

[0053] In addition, the outer shape of the punch 5 is a single perfect circle, which simplifies the construction.

[0054] In addition, the circular arc portions 9 and 11 are arranged in a concentric shape, making it easier to adjust the shape.

[0055] The adjacent circular arc portions 9 and 11 are continuous in the circumferential direction via the non-circular arc portion 13, so they can be provided only in the necessary locations. As a result, the shape adjustment at the non-circular arc portion 13 can be omitted, and the shape adjustment of the circular arc portions 9 and 11 can be made more easily.

[0056] Furthermore, in the blanking method of this embodiment, the circumferential positions of the circular arc portions 9 and 11 in the internal shape of the die 7 are set according to the anisotropy of the steel plate W, thereby reliably improving the roundness of the blanked iron chip 3.

[0057] It should be noted that the internal shape of the die 7 and the external shape of the punch 5 can also be reversed, with the external shape of the punch 5 being a non-circular shape and the internal shape of the die 7 being a perfect circle. Alternatively, both the internal shape of the die 7 and the external shape of the punch 5 can be made to be non-circular.

[0058] [Variation Example]

[0059] Figure 5 This is a top view showing the internal shape of the die and the external shape of the punch of the blanking fixture in the modified example of Embodiment 1.

[0060] exist Figure 5 In the modified example, the internal shape of the die 7 is the same as in Example 1, and the external shape of the punch 5 is also set to be of different diameters as the internal shape of the die 7. That is, the external shape of the punch 5 has two kinds of circular arc portions 15 and 17. The circular arc portion 15 with a relatively smaller diameter is located on both sides in the conveying direction of the steel plate W, and the circular arc portion 17 with a relatively larger diameter is located on both sides in the width direction of the steel plate W.

[0061] The circular arc portions 15 and 17 of the punch 5 are arranged parallel to the circular arc portions 9 and 11 of the die 7, respectively. The circular arc portions 15 and 17 of the punch 5 are continuous by a straight non-circular arc portion 19 extending in a direction inclined relative to the radial direction.

[0062] In this modified example, in addition to the internal shape of the die 7, the external shape of the punch 5 is also of different diameters, which allows for more flexible improvement of the roundness of the iron chip 3.

[0063] Figure 6 This is a top view showing the internal shape of the die and the external shape of the punch of a blanking fixture in other variations of Embodiment 1, superimposed. It should be noted that... Figure 6 In the middle, the non-circular arcs 13 and 19 are represented by thin dashed lines.

[0064] exist Figure 6 In a modified example, the gap between the punch 5 and the die 7 is constant. In this modified example, the circular arc portions 9 and 11 of the unequal diameter die 7 are separated in the circumferential direction, and the non-circular arc portion 13 is formed as a curve connecting the circumferential ends of the circular arc portions 9 and 11.

[0065] Similarly, the circular arc portions 15 and 17 of the punches 5 with different diameters are separated in the circumferential direction, and the non-circular arc portion 19 is formed as a curve connecting the circumferential ends of the circular arc portions 15 and 17. It should be noted that the non-circular arc portions 13 and 19 can also be formed as straight lines instead of curves.

[0066] In Figure 6 In the modified example, the shapes of the circular arc portions 9 and 11, as well as the circular arc portions 15 and 17, can be adjusted more easily. It should be noted that it is also possible to set either the internal shape of the die 7 or the external shape of the punch 5 to be of different diameters, and set the other to be circular.

[0067] Figure 7 This is a top view showing the internal shape of the die and the external shape of the punch of a blanking fixture in another variation of Embodiment 1, superimposed. It should be noted that... Figure 7 In the middle, the non-circular arcs 13 and 19 are represented by thin dashed lines.

[0068] Figure 7The variation is in Figure 6 In a modified example, the centers of the circular arc portions 9 and 11 of the inner shape of the die 7 are offset from each other, and the centers of the circular arc portions 15 and 17 of the outer shape of the punch 5 are offset from each other.

[0069] It should be noted that the centers of the circular arc portions can be offset in either the internal shape of the die 7 or the external shape of the punch 5, while the circular arc portions are made concentric in the other direction. Alternatively, either the internal shape of the die 7 or the external shape of the punch 5 can be made with unequal diameters, while the other is made perfectly circular.

[0070] In this modified example, by staggering the positions of the centers of the circular arc portions 9, 11, 15, and 17, the roundness of the iron chip 3 can be improved more flexibly.

[0071] Figure 8 This is a top view showing the internal shape of the die and the external shape of the punch of another variation of the blanking fixture in Embodiment 1.

[0072] Figure 8 The variant example relative to Figure 6 In a modified example, the non-circular arc portions 13 and 19 are set to be arc-shaped in the opposite direction to the respectively continuous circular arc portions 9 and 11 and circular arc portions 15 and 17. In this modified example, welding grooves, radial protrusions, keys, etc., based on the shape of the non-circular arc portions 13 and 19 can be formed on the punched iron chip 3. Alternatively, the non-circular arc portions 13 and 19 can avoid the already formed welding grooves, radial protrusions, keys, etc. It should be noted that it is also possible to set only one of the internal shape of the die 7 and the external shape of the punch 5 to be of different diameters, and set the other to be circular.

[0073] Figure 9 This is a top view of a steel plate showing another variation of Embodiment 1.

[0074] like Figure 9 As shown, steel sheet W is coiled into a roll shape and placed on an uncoiler (not shown), and is sequentially fed out for punching. During its manufacturing process, this steel sheet W sometimes experiences what is known as transverse bending. For example... Figure 9 As indicated by the arrow, lateral bending is the bending of the steel plate W in the width direction with one side being the inside and the other the outside, respectively.

[0075] The transverse bending affects the anisotropy of the steel plate W depending on its direction. Therefore, in this modified example, the steel plate W is arranged such that the direction of the transverse bending of the steel plate W is a predetermined direction, and the iron chip 3 is punched out from the steel plate W with the transverse bending direction as a predetermined direction, as in the above embodiment.

[0076] Therefore, even if the steel plate W has lateral bending, the roundness of the punched part of the iron chip 3 can be reliably improved.

[0077] Example 2

[0078] Figure 10 This is a top view showing the internal shape of the die and the external shape of the punch of the blanking fixture in Embodiment 2, superimposed. It should be noted that... Figure 10 In the figures, non-circular arcs are represented by thin dashed lines. Furthermore, in Embodiment 2, the basic structure is the same as in Embodiment 1, and the same reference numerals are used to indicate structures identical or corresponding to those in Embodiment 1, with repeated descriptions omitted.

[0079] The blanking fixture 1 in Embodiment 2 is a blanking fixture with three types of circular arc portions 9, 21, 11 and 15, 23, 17, respectively, where the internal shape of the die 7 and the external shape of the punch 5 are respectively set to different diameters. It should be noted that it is also possible to set only one of the internal shape of the die 7 and the external shape of the punch 5 to be different diameters, and set the other to be circular.

[0080] The radii of curvature of the circular arc portions 9, 21, and 11 of the die 7 are set to relatively large, medium, and small, respectively. The circular arc portion 21 with a medium radius of curvature is located on both sides of the steel plate W in the conveying direction. The circular arc portions 9 and 11 with large and small radii of curvature are located on either side of the circular arc portion 21 with a medium radius of curvature, separated by a non-circular arc portion 13. The non-circular arc portion 13 can be curved, but it can also be straight.

[0081] The circular arc portions 15, 16, and 17 of the punch 5 are arranged in the same manner as the circular arc portions 9, 21, and 11 of the die 7. That is, the circular arc portion 23 with a radius of curvature of medium is located on both sides of the conveying direction of the steel plate W, and the circular arc portions 15 and 17 with radii of curvature of large and small are located on both sides of the circumference of the circular arc portion 23, separated by the non-circular arc portion 19. The non-circular arc portion 19 is curved, but it can also be straight.

[0082] Figure 11 This is a top view showing the internal shape of the die and the external shape of the punch of the blanking fixture in the modified example of Embodiment 2.

[0083] exist Figure 11In the modified example, only the external shape of the punch 5 has three circular arc portions 15, 23, and 17, while the internal shape of the die 7 is circular. Among the circular arc portions 15, 23, and 17 of the punch 5, the circular arc portion 15 with a relatively large radius of curvature and the circular arc portion 17 with a relatively small radius of curvature are located on both sides of the width direction and on both sides of the conveying direction, respectively. The circular arc portion 23 with a medium radius of curvature is located between the circular arc portions 15 and 17 with large and small radii of curvature in the circumferential direction, separated by a non-circular arc portion 19. The non-circular arc portion 19 is a straight line along the radial direction.

[0084] In this embodiment 2 and its variations, in addition to achieving the same effect as in embodiment 1, the roundness of the iron chip 3 can be improved more flexibly.

[0085] Example 3

[0086] Figure 12 This is a top view showing the internal shape of the die and the external shape of the punch of the blanking fixture in Embodiment 3. It should be noted that in Embodiment 3, the basic structure is the same as in Embodiment 1, and the same reference numerals are used to indicate the same or corresponding structures as in Embodiment 1, and repeated descriptions are omitted.

[0087] The blanking fixture 1 in Embodiment 3 is a blanking fixture with different diameters for the internal shape of the die 7 and the external shape of the punch 5, and has three different circular arc portions 9, 21, 11 and 15, 23, 17 arranged in the circumferential direction. It should be noted that it is sufficient to have two or more circular arc portions with different internal shapes of the die 7 and external shapes of the punch 5.

[0088] The circular arc portions 11, 9, and 21 of the die 7 are arranged clockwise along the circumference in the order of large, small, and medium radii of curvature. The circular arc portions 17, 23, and 15 of the punch 5 are arranged clockwise along the circumference in the order of large, medium, and small radii of curvature.

[0089] In this embodiment 3, in addition to achieving the same effect as in embodiment 1, the roundness of the iron chip 3 can be improved more flexibly.

[0090] Symbol Explanation

[0091] 1—Blanking fixture; 3—Iron chip (part); 5—Punch; 7—Die; 9, 11, 15, 17, 21, 23—Circular arc portion; 13, 19—Non-circular arc portion; W—Steel plate.

Claims

1. A blanking fixture for blanking components with circular blanking portions from steel plates, characterized in that, have: Punch; and The punch enters the die, enabling the blanking of the component. At least one of the external shape of the punch and the internal shape of the die is a shape with two or more circular arcs having different radii of curvature.

2. The blanking fixture according to claim 1, characterized in that, One of the external shape of the punch and the internal shape of the die is the non-diameter shape. The external shape of the punch and the internal shape of the die are both a single perfect circle.

3. The blanking fixture according to claim 1, characterized in that, Both the external shape of the punch and the internal shape of the die are of the different diameters.

4. The blanking fixture according to any one of claims 1 to 3, characterized in that, The two or more circular arc portions are arranged concentrically.

5. The blanking fixture according to any one of claims 1 to 3, characterized in that, The adjacent circular arc portions in the circumferential direction are continuous in the circumferential direction via non-circular arc portions.

6. A punching method for punching out a component with a circular punched portion from a steel plate, characterized in that, Based on the anisotropy of the steel plate, the circumferential position of two or more circular arc portions with different radii of curvature is set on at least one of the external shape of the punch and the internal shape of the die. The punch is brought into the die to punch the part out of the steel plate between the punch and the die.

7. The punching method according to claim 6, characterized in that, The steel plate is arranged such that its transverse bending direction is a predetermined direction, and the component is punched out from the steel plate.

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