JP2024057694A - Layered product and manufacturing method for layered product - Google Patents

Abstract

To provide a layered product in which the bonding strength between a metal plate member as an upper layer and a metal plate member as a lower layer is enhanced, and to provide a method for manufacturing the layered product with high production efficiency.SOLUTION: A layered product 1 is constituted by integrally layering metal plate members W. Each of the metal plate members W has a recessed part 13 formed on a front surface 11 and a projecting part 14 formed on a rear surface 12 and capable of being fitted in the recessed part 13 by half-blanking. The projecting part 14 has a plurality of cut-out parts 21 formed inward from a side of a circumference 20 or quadrangle 23 in a plan view and is integrated by fitting the recessed part 13 of one metal plate member W onto the projecting part 14 of the other metal plate member W. This makes it possible to enhance the bonding strength between the metal plate member W as an upper layer and the metal plate member W as a lower layer.SELECTED DRAWING: Figure 2

Description

The present invention relates to a laminated product and a method for manufacturing a laminated product.

Laminated products are made by stacking and integrating a certain number of metal plate members. Each layer of metal plate member has a circular recess formed on one surface by half-punching part of the metal plate member, and a circular protrusion formed on the reverse surface. Laminated products are made by repeatedly fitting the protrusion of the upper metal plate member into the recess of the lower metal plate member, integrating multiple metal plate members.

However, simply fitting the circular convex and concave portions together may result in weak bonding strength (adhesion strength) when the laminated metal plate members are thin, such as 0.5 mm, and the upper and lower metal plate members may peel off or float. To increase the bonding strength of the metal plate members, a method for manufacturing a laminated product has been disclosed in which the convex portion of the upper layer is fitted into the concave portion of the lower metal plate member to integrate them, and then the tip of a punch is pressed against the concave portion of the upper metal plate member (see, for example, Patent Document 1).

Similarly to Patent Document 1, Patent Document 2 discloses a laminated product in which a part of a metal plate member is subjected to half-punching to form a circular recess on one surface and a circular protrusion on the back surface, and multiple metal plate members are integrated by repeatedly fitting the protrusion of the upper metal plate member into the recess of the lower metal plate member. The planar shapes of the protrusions and recesses of this metal plate member are not limited to circles, and examples include triangular, rectangular, square, or track shapes.

Patent Document 3 also discloses the formation of recesses and protrusions that have a trapezoidal cross-sectional shape and a rectangular planar shape, known as a mountain shape.

JP 2000-125519 A JP 2004-324760 A JP 2020-22255 A

The manufacturing method of a laminated product described in Patent Document 1 is to fit the convex part of the upper layer into the concave part of the lower metal plate member to integrate them, and then press the tip of a punch into the concave part of the upper metal plate member. According to this manufacturing method, the part compressed by the tip of the punch moves in the outer circumferential direction, thereby increasing the degree of bonding between the convex part of the upper metal plate member and the concave part of the lower metal plate member. However, if the tip of the punch is simply pressed, the amount of movement of the convex part in the outer circumferential direction is small, and there is a risk that sufficient bonding strength cannot be obtained. In addition, since the tip of the punch is pressed into the concave part of the upper metal plate member after the convex part of the upper layer is fitted into the concave part of the lower metal plate member to integrate them, the number of processing steps is increased, and therefore productivity cannot be said to be good. In order to increase the bonding strength, pressing with a punch is required in each layer, which further increases the number of processing steps.

In the laminated product described in Patent Document 2, the convex and concave shapes are circular, triangular, rectangular, square, or track-shaped. However, even with these shapes, if the convex and concave parts have the same external size, the contact area between the convex and concave parts is not significantly larger than when they are circular, so no improvement in bonding strength can be expected.

The laminated product described in Patent Document 3, like the laminated product described in Patent Document 1, is manufactured by fitting the convex portion of the upper layer into the concave portion of the lower metal plate member to integrate them, and then pressing the tip of a punch (called a push punch) into the concave portion of the upper metal plate member, and moving the portion compressed by the tip of the punch toward the inclined side of the mountain shape. However, when the metal plate member is a thin plate, it is difficult to obtain sufficient bonding strength because the pressing force generated when pressing with the punch escapes on the inclined surface. Also, like Patent Document 1, there is an issue that the process of pressing the concave portion with the punch is added.

Methods other than the manufacturing method of the laminated product described in the above patent document include side welding and bonding of metal plate members, but these methods have the problem of increasing the number of processes and costs.

Therefore, the present invention has been made to solve these problems, and aims to realize a laminated product with improved bonding strength between the upper metal plate member and the lower metal plate member, and a highly productive manufacturing method for the laminated product.

[1] The laminated product of the present invention is a laminated product formed by laminating and integrating metal plate members, and the metal plate members have a recess formed on the front surface of the metal plate member by half-punching, and a protrusion formed on the back surface that can fit into the recess, and the protrusion has a number of cuts formed inward from the circumference or sides of a polygon in plan view, and are integrated by fitting the protrusion of one metal plate member into the recess of the other metal plate member.

[2] In the laminated product of the present invention, when the recess of the lower metal plate member and the protrusion of the upper metal plate member are fitted together, it is preferable that a tightening margin is provided around the entire circumference of the contacting side surfaces of the recess and the protrusion.

"3" In the laminated product of the present invention, it is preferable that multiple cuts are provided at equal intervals along the circumference.

[4] In the laminated product of the present invention, it is preferable that the bottom of the cut portion, the top of the protrusion formed between adjacent cut portions, and the position connecting the cut portion and the top are formed as arcs.

[5] In the laminated product of the present invention, it is preferable that the depth of the recess from the front surface is greater than the height of the protrusion from the back surface.

[6] The method for manufacturing a laminated product of the present invention includes the steps of forming a through hole in a metal sheet material that is to be the bottom layer, the step of punching out a metal sheet member that is to be the bottom layer from the metal sheet material, the step of forming the convex portion having a substantially U-shaped cut portion formed from a circumference or a side of a polygon toward the inside and a protrusion portion formed between adjacent cut portions by half punching, and the step of forming a recess having a shape that is to be the convex portion and into which the convex portion can be fitted, and the step of punching out a metal sheet material in which the concave portion and the convex portion have been formed, the step of punching out a metal sheet member that is to be the bottom layer immediately above the bottom layer. The method includes a process of punching out the outer shape of the metal plate member to be formed and fitting the convex portion into the through hole, a process of forming the concave portion and the convex portion of the metal plate member that is a layer above the metal plate member that is to be the upper layer in the metal plate material, and a process of punching out the outer shape of the metal plate member that is a layer above the metal plate member that is to be the upper layer and fitting the convex portion of the upper layer into the concave portion of the lower layer, and is characterized in that the process of forming the concave portion and the convex portion and the process of punching out the outer shape of the metal plate member to be the upper layer and fitting the convex portion of the upper layer into the concave portion of the lower layer are repeated until a predetermined number is reached.

The laminated product of the present invention is integrated by fitting the protrusion of the upper metal sheet member into the recess of the lower metal sheet member. The protrusion has a cut portion formed from the circumference or the side of a polygon toward the inside, and a protrusion formed between adjacent cut portions. The recess and protrusion have the same shape in a plan view because they are formed by half-punching. Therefore, the length of contact between the protrusion and the recess when they are fitted into each other, i.e., the contact area of the outer peripheral side, is larger than when the recess and protrusion are simply circular or rectangular in shape, making it possible to increase the bonding strength between the upper metal sheet member and the lower metal sheet member.

However, in the case of the conventional technology in which the recesses and protrusions are simply circular or rectangular, when the protrusion of the upper metal plate member is fitted into the recess of the lower metal plate member, the compressive force generated on the mutual contact side faces may be directed toward the outside of the recess, causing the outer periphery of the recess of the unregulated metal plate member to deform in the planar direction or expand in the thickness direction, and sufficient bonding strength may not be obtained. In the laminated product of the present invention, the recesses and protrusions formed on the metal plate member are composed of multiple cuts and protrusions. Therefore, when the protrusion of the upper metal plate member is fitted into the recess of the lower metal plate member, the compressive force generated on the mutual contact side faces acts to sandwich each protrusion, making it possible to obtain sufficient bonding strength. In addition, the contact area of the outer periphery of the recesses and protrusions is increased, making it possible to increase the bonding strength.

In addition, the manufacturing method of the laminated product of the present invention forms recesses and protrusions by half-punching, punches out the outer shape of a metal plate member from the metal plate material with the recesses and protrusions formed, and integrates the recesses of the lower metal plate member by fitting the protrusions of the upper metal member into the recesses of the lower metal plate member. These steps can be performed continuously, for example, using a progressive die. In addition, this method is more productive than conventional side welding and bonding of metal plate members, and furthermore, since sufficient bonding strength can be obtained without the pressing step using a punch (push punch) as in the conventional technology described above, it is possible to increase productivity.

As a result of the above, the present invention makes it possible to provide a laminated product with improved bonding strength between the upper metal plate member and the lower metal plate member, and a highly productive method for manufacturing the laminated product.

FIG. 2 is a diagram showing an example of a configuration of a laminated product 1. 3 is a diagram showing a schematic configuration of a recess 13 and a protrusion 14 according to a first example. FIG. FIG. 4 is a plan view showing a detailed configuration of a protrusion 14 according to the first example. 13A and 13B are diagrams illustrating a configuration of a convex portion 14 according to a second example. 13A and 13B are diagrams illustrating a configuration of a protrusion 30 according to a third example. 13A and 13B are diagrams illustrating a configuration of a convex portion 40 according to a fourth example. 13A and 13B are diagrams illustrating a configuration of a convex portion 40 according to a fifth example. 13A and 13B are diagrams illustrating a configuration of a convex portion 50 according to a sixth example. FIG. 2 is a process flow diagram showing a method for manufacturing the laminated product 1.

The laminated product 1 and the manufacturing method of the laminated product 1 according to the embodiment of the present invention will be described below with reference to Figures 1 to 9.

(Configuration of laminated product 1)
FIG. 1 is a diagram showing one configuration example of a laminated product 1. FIG. 1(a) is a plan view, and FIG. 1(b) is a cross-sectional view taken along the line A-A in FIG. 1(a). The laminated product 1 is formed by laminating a plurality of metal plate members W and joining them at a joining portion 10. The metal plate member W shown in FIG. 1(a) has a substantially U-shape, but the shape is not limited thereto. In the metal plate member W, the material of the metal plate member W used in this example is, for example, pure iron or electromagnetic steel plate, and the laminated product 1 is a terminal of a laminated current sensor, a core of a motor, or the like. The thickness T0 (see FIG. 2(c)) of the metal plate member W used in this way is generally a thin plate having a thickness of 0.3 mm to 0.5 mm, and the width of the metal plate member W in this example is 1.5 mm. However, the laminated product 1 can also be applied to iron-based materials other than pure iron and electromagnetic steel plate, copper-based materials, and the like. It should be noted that the connecting portions 10 shown in FIG. 1( a ) represent one example of an arrangement, and the number and arrangement of the connecting portions 10 are appropriately set according to the overall size, width and shape of the metal plate member W.

As shown in FIG. 1(b), the laminated product 1 is composed of eight layers of metal plate members W, which are designated as metal plate members W1, W2, W3, W4, W5, W6, W7, and W8 from the top to the bottom. In the following description, when it is possible to commonly describe the metal plate members W1 to W8, they may be collectively referred to as metal plate members W. The number of metal plate members W is not limited to eight, and it is possible to have a smaller number or a larger number. The configuration of the metal plate member W will be described using the metal plate member W1 as a representative example. In the metal plate member W1, a recess 13, which is a depression, is formed from one surface 11 at the position of each joint 10, and a protrusion 14 is protruded from the other back surface 12. The recess 13 and the protrusion 14 are formed by half-punching the metal plate member W1 using a press die. Therefore, the planar shape of the recess 13 is the same as the planar shape of the protrusion 14, although they are in a concave-convex relationship. In addition, when the metal plate member W is a thin plate with a thickness T0 (see FIG. 2C) of 0.3 mm to 0.5 mm, as in this example, half-punching can also be considered an extrusion process.

Metal plate members W2 to W7 have the same configuration as metal plate member W1, and the convex portion 14 of the upper metal plate member W1 can be fitted into the concave portion 13 of the lower metal plate member W2. The convex portion 14 is larger than the shape of the concave portion 13 by an amount corresponding to the tightening margin. In other words, the metal plate members W1 and W2 are joined by fitting (pressing) the convex portion 14 of the upper metal plate member W1 into the concave portion 13 of the lower metal plate member W2. Similarly, the metal plate members W2 and W3, the metal plate members W3 and W4, the metal plate members W4 and W5, the metal plate members W5 and W6, and the metal plate members W6 and W7 are configured so that the convex portion 14 of the upper layer can be fitted into the concave portion 13 of the lower layer.

The lowermost metal plate member W8 has a through hole 15 formed therein, which has the same planar shape as the recess 13. The metal plate members W7 and W8 are joined by fitting the protrusion 14 of the upper metal plate member W7 into this through hole 15. The laminated product 1 is constructed by sequentially joining the lowermost metal plate member W8 to the upper metal plate members W7 to W1. Note that if it is acceptable for the protrusion 14 to protrude from the rear surface 12 of the lowermost metal plate member W8, it is possible for all of the metal plate members W1 to W8 to have the same configuration. The recess 13 and protrusion 14 can be adapted to various shapes, which will be explained using the first to sixth examples.

(First Example)
FIG. 2 is a diagram showing a schematic configuration of the recess 13 and the protrusion 14 according to the first example. FIG. 2(a) is a perspective view of the recess 13 seen from the front surface 11 side, FIG. 2(b) is a perspective view of the protrusion 14 seen from the back surface 12 side, and FIG. 2(c) is a cross-sectional view cut along the cutting line A-A in FIG. 2(a). As shown in FIG. 2(a), the recess 13 is a recessed portion formed on the front surface 11 of the raw metal plate material W0. As shown in FIG. 2(b), the protrusion 14 is a portion protruding from the back surface 12 of the metal plate material W0, and the recess 13 has the same shape (similar shape) as the protrusion 14 in a plan view. However, the outer peripheral shape of the protrusion 14 is formed larger over the entire outer peripheral shape of the recess 13 by an amount corresponding to the tightening margin. After forming the recess 13 and the protrusion 14 in the metal plate material W0 by half-punching, or after forming the through hole 15, the metal plate members W1 to W8 are formed by punching out the outer shape.

2(c), the depth T1 of the recess 13 from the surface 11 of the recess 13 and the height T2 of the protrusion 14 from the back surface 12 are approximately 1/2 the thickness T0 of the metal plate member W. However, the depth T1 of the recess 13 is formed to be deeper than the height T2 of the protrusion 14, for example, by about 0.05 mm. In this way, by making the depth T1 of the recess 13 deeper than the height T2 of the protrusion 14, when the upper metal plate member W and the lower metal plate member W are joined, a gap is formed in the thickness direction between the recess 13 and the protrusion 14, so that the upper and lower metal plate members W can be closely attached to each other. In addition, when the protrusion 14 is fitted (pressed) into the recess 13, cutting chips and the like may be generated, but the generated cutting chips and the like can be absorbed by this gap. Note that the remaining thickness T3 when the recess 13 is formed is the difference between the thickness T0 of the metal plate material W0 and the depth T1 of the recess 13, so the depth T1 is determined so that the balance between the strength of the remaining thickness portion and the required joining strength is favorable. In addition, in the first to sixth examples described below, the cross-sectional structure of the metal plate member W can be described in the same way, so the description of the cross-sectional shape may be omitted.

Figure 3 is a plan view showing the detailed configuration of the convex portion 14 according to the first example. Note that the metal plate members W1 to W7 have the same configuration, and therefore will be described as the metal plate member W. Also, as shown in Figure 2, the concave portion 13 and the convex portion 14 have a concave-convex relationship (inverted relationship), but have the same shape when viewed in plan from the back surface 12 side, and therefore the detailed configuration will be described using the convex portion 14. In other words, the cut portion 21 of the convex portion 14 is a protruding portion of the concave portion 13, and the protruding portion 22 of the convex portion 14 is a cut portion of the concave portion 13. The convex portion 14 has a substantially U-shaped cut portion 21 that faces inward from the circumference 20. The cut portions 21 are provided at four equal intervals along the circumference 20. However, the cut portions 21 do not necessarily have to be geometrically exactly equal intervals. The protruding portion 22 is formed between adjacent cut portions 21. The bottom 21a of the cutout 21 is formed by a circular arc R1, and the top 22a of the protrusion 22 is formed by a circular arc R2. In the example shown in FIG. 3, the circular arcs R1 and R1 are directly connected. However, the protrusion 22 may be shaped so that the circular arcs R1 and R2 are connected by a straight line. The circumference 20 is sometimes referred to as the circumscribing circle 20 because it is the circumscribing circle of the four tops 22a. In FIG. 3, the symbol P is the centroid of the protrusion 14.

The relationship between the cutout 21 and the protrusion 22 will be described with reference to FIG. 3. In the first example, the minimum width H1 of the cutout 21 is approximately the same as the minimum width H2 of the protrusion 22, and the cutout depth D of the cutout 21 is formed to be approximately the same as the minimum width H1. In this example, the minimum width H1 of the cutout 21 corresponds to the diameter of the arc R1. As shown in FIG. 3, in the first example, the top 22a of the protrusion 22 and the bottom 21a of the cutout 21 are each formed by four arcs R1 and R2. In this way, the convex portion 14 has a shape including the arc R2 that constitutes the four tops 22a and the arc R1 that constitutes the bottoms 21a of the four cutouts 21. Therefore, in the areas where the arcs R1 and R2 are formed, the meshing force with the recess 13, i.e., the compressive stress, is high, and the contact area of the outer peripheral side surface is larger than when the protrusion 14 is a simple circle, thereby increasing the bonding strength between the upper metal plate member W and the lower metal plate member W.

As shown in FIG. 3, the convex portion 14 can be said to be formed with a rectangle 23 as its base shape. In this example, the rectangle 23 is a square. In other words, the cut-outs 21 are formed on each of the four sides 24 of the rectangle 23, and the four apex angles are formed into an inscribed circle (arc R2) to form the protrusion 22. In the laminated products described in Patent Documents 1 and 2, the outer shapes of the concave portion 13 and the convex portion 14 are formed into a simple circle, triangle, or rectangle. In contrast, in this example, by providing the cut-outs 21, the contact length of the concave portion 13 and the convex portion 14, that is, the contact area of the outer peripheral side surface, can be increased even if the base shape is a rectangle.

In the example shown in FIG. 3, the minimum width H2 of the protrusion 22 on the convex portion 14 side is approximately the same as the thickness T0 of the metal plate member W. In this way, the cross-sectional shape when cut at the position of the minimum width H2 is a square. Therefore, the strength of the protrusion 22 in the thickness direction and the strength in the lateral direction are approximately the same, and there is no bias in strength between the thickness direction and the lateral direction. However, the minimum width H1 of the cutout portion 21, the minimum width H2 of the protrusion 22, and the cut depth D of the cutout portion 21 do not necessarily have to be the same as long as the side contact area is made larger than the circumference 20 or the outer periphery length of the rectangle 23 (side contact area). The minimum width H2 of the protrusion 22 can be made as small as the height T2 of the protrusion 22 from the back surface 12.

(Second Example)
FIG. 4 is a diagram showing the configuration of the convex portion 14 according to the second example. The concave portion 13 and the convex portion 14 shown in FIG. 4 are modified examples in which the number of the protrusions 22 in the first example shown in FIG. 3 is increased from four to six. The metal plate members W1 to W7 have the same configuration, and the cross-sectional shape can be described in the same way as in FIG. 2(c), so illustration is omitted. In addition, the concave portion 13 and the convex portion 14 have a concave-convex relationship (inverted relationship), but have the same shape when viewed in plan from the back surface 12 side, so the configuration of the convex portion 14 will be described as an example. In other words, the cut portion 21 of the convex portion 14 is a protrusion portion of the concave portion 13, and the protrusion portion 22 of the convex portion 14 is a cut portion of the concave portion 13. The convex portion 14 has the cut portion 21 extending inward from the circumference 20. The cut portions 21 are provided at six equal intervals along the circumference 20. However, the cut portions 21 do not necessarily have to be geometrically exactly equal intervals. The protrusion portion 22 is between the adjacent cut portions 21. The bottom 21a of the cutout 21 is formed by a circular arc R1, and the top 22a of the protrusion 22 is formed by a circular arc R2. In the example shown in Fig. 4, the circular arcs R1 and R1 are directly connected. However, the protrusion 22 may be shaped so that the circular arcs R1 and R2 are connected via a straight line. The circumference 20 is a circumscribing circle of the six tops 22a, and is therefore sometimes referred to as the circumscribing circle 20.

The relationship between the cut portion 21 and the protrusion portion 22 will be described with reference to FIG. 4. The minimum width H1 of the cut portion 21 is approximately the same as the cut depth D, and the minimum width H2 of the protrusion portion 22 is greater than the cut depth D and the minimum width H1 of the cut portion 21. In this example, the minimum width H1 of the cut portion 21 corresponds to the diameter of the arc R1. However, the minimum width H2 of the protrusion portion 22 may be formed to be approximately the same as the cut depth D and the minimum width H1 of the cut portion 21. For example, as in the first example, the minimum width H2 of the protrusion portion 22 can be reduced to the same extent as the height T2 of the protrusion portion 22 from the back surface 12. In this way, the convex portion 14 has a shape including the arc R2 constituting the six tops 22a and the arc R1 constituting the bottoms 21a of the six cut portions 21. Therefore, the contact area of the outer peripheral side surface can be made larger than in the first example shown in FIG. 3, and the number of protrusions 22 increases, so the interlocking force with the recesses 13 is stronger, and the bond strength between the upper metal plate member W and the lower metal plate member W is stronger than in the first example.

As shown in FIG. 4, the convex portion 14 can be said to be formed based on a hexagon 25. In other words, the cut portions 21 are formed on each of the six sides 26 of the hexagon 25, and the six apex angles are formed by the arc R2, which is an inscribed circle. The number of cut portions 21 and protrusions 22 is not limited to six, and may be increased or decreased to five or eight. In other words, it is also possible to provide a cut portion 21 on each side of a polygon such as a pentagon or octagon.

(Third Example)
FIG. 5 is a diagram showing the configuration of the convex portion 30 according to the third example. The concave portion 31 and the convex portion 30 are in a concave-convex relationship (inside-out relationship), so the configuration of the convex portion 30 will be described. The third example is a modified example of the second example already described, and the shape of the protrusion portion 32 is different. The same reference numerals as in FIG. 4 are used to describe parts that can be commonly described with FIG. 4. Note that the recessed portion that is paired with the convex portion 30 is the concave portion 31. The convex portion 30 has a substantially U-shaped cut portion 21 formed from the circumference 20 toward the inside. The cut portions 21 are provided at six equally spaced locations along the circumference 20. The portions between the adjacent cut portions 21 form the protrusion portions 32. The bottom portion 21a of the cut portion 21 is formed by a circular arc R1.

Here, among the protrusions 32, the protrusions 32a and 32b arranged diagonally are composed of the arc R1 of the bottom 21a, the straight line portion 32c extending the tangent of the arc R1 until it intersects with the circumference 20, and the outer periphery 33 which is a part of the circumference 20 in the area sandwiched between the two straight lines 32c. The intersection of the outer periphery 33 and the straight line portion 32c is connected by the arc R3. The other protrusions 32 other than the protrusions 32a and 32b are also composed in the same manner. The protrusions 32 are formed by the outer periphery 33 of the protrusions 32, the straight line portion 32c, and 12 small diameter arcs R3. In this way, the convex portion 14 has a shape including a large number of small diameter arcs R3 and the arc R1 of the bottom 21a of the cut portion 21. In the third example, the number of protrusions 32 is the same as in the second example, and the contact area of the side is also the same, but the number of arcs R3 at the tips of the protrusions 32 is greater than in the second example. Therefore, in the area where the arcs R3 are formed, the meshing force with the recesses 13 is high, making it possible to increase the bonding strength between the upper metal plate member W and the lower metal plate member W.

Next, the fourth and fifth examples will be described with reference to Figures 6 and 7. The fourth and fifth examples are examples in which the outer shapes of the protrusions 40 and 50 are substantially rectangular.

(Example 4)
FIG. 6 is a diagram showing the configuration of the convex portion 40 according to the fourth example. Although not shown, the recessed portion that is paired with the convex portion 40 is a recessed portion 41. The convex portion 40 and the recessed portion 41 are in a convex-concave relationship (inside-out relationship), so the configuration of the convex portion 40 will be described. The convex portion 40 has a substantially U-shaped cut portion 43 formed from the center of the four sides 42 of a quadrangle (a square in this example) toward the inside. The cut portion 43 is provided in the center of each side 42. The space between the adjacent cut portions 43 becomes a protrusion portion 44. The protrusion portion 44 is provided at the four corners of the quadrangle, and the planar shape of the protrusion portion 44 is substantially quadrangular. The bottom portion 43a of the cut portion 43 is formed by a circular arc R1, and the top portion 45 and other corner portions 46 of the protrusion portion 44 are formed by a circular arc R4. The four top portions 45 of the protrusion portion 44 are in contact with a circumscribed circle 47.

The relationship between the cut portion 43 and the protrusion portion 44 will be described with reference to FIG. 6. The minimum width H1 of the cut portion 43 is smaller than the cut depth D, and the minimum width H2 of the protrusion portion 44 is larger than the minimum width H1 of the cut portion 43 and smaller than the cut depth D. The minimum width H1 of the cut portion 43, the minimum width H2 of the protrusion portion 44, and the cut depth D of the cut portion 43 may be the same or different in size as long as they are larger than the peripheral length (contact area of the side surface) of a simple rectangle, and can be set appropriately. For example, the minimum width H2 of the protrusion portion 44 can be made as small as the height T2 of the protrusion portion 44 from the back surface 12. In one protrusion portion 44, the top portion 45 and the corner portion 46 are each connected by an arc R4. In this way, the protrusion 44 is formed in a shape that includes many small-diameter arcs R4 and the arc R4 of the bottom 43a of the notch 43, which increases the engagement force with the recess 13, and also increases the contact area of the outer peripheral side surfaces of the recess 41 and the protrusion 40 compared to when the external shape is a simple rectangle, making it possible to increase the connection strength.

(Fifth Example)
FIG. 7 is a diagram showing the configuration of the convex portion 40 according to the fifth example. The fifth example is a modified example of the fourth example (see FIG. 6), and differences from the fourth example will be described. The same reference numerals as in FIG. 6 are used for the parts that can be commonly described with the fourth example. The convex portion 40 of the fifth example is different in that a second cut portion 48 is provided at the position of the apex 45 of the fourth example, and small protrusions 44a, 44b are formed on both sides of the second cut portion 48. That is, the protrusion 44 is composed of two small protrusions 44a, 44b. Therefore, while the convex portion 50 of the fourth example has four protrusions 44, the fifth example has eight small protrusions 44a, 44b. The small protrusions 44a, 44b have corners formed by circular arcs R4.

The fifth example configured in this manner does not differ significantly from the fourth example in the contact area of the outer peripheral side surface between the convex portion 40 and the concave portion 41, but the engagement force of the eight small protrusions 44a, 44b with the concave portion 41 is increased, making it possible to increase the bonding strength between the upper metal plate member W and the lower metal plate member W more than in the fourth example.

(Example 6)
FIG. 8 is a diagram showing the configuration of the convex portion 50 according to the sixth example. Although not shown, the recessed portion that is paired with the convex portion 50 is a recessed portion 51. The convex portion 50 and the recessed portion 51 are in a convex-concave relationship (inside-out relationship), so the configuration of the convex portion 50 will be described. The convex portion 50 has a substantially U-shaped cut portion 53 formed from each of the four sides 52 toward the inside. The cut portion 53 is formed at a position biased in the same direction from the center of each side. In the example shown in FIG. 8, the cut portion 53 is biasedly arranged at a position among the four sides 52 that leaves the minimum width H2 of the protrusion portion 54. The space between the adjacent cut portions 53 becomes the protrusion portion 54. The protrusion portion 54 is provided at four places, the bottom portion 53a of the cut portion 53 is formed by an arc R5, and the top portion 55 of the protrusion portion 54 is formed by an arc R6. The top portions 55 of the four corners of the protrusion portion 54 are in contact with the circumscribed circle 57.

In the example shown in FIG. 8, the arcs R5 and R6 are the same size. The minimum width H2 of the protrusion 54 is formed to be the same as the minimum width H1 of the cut 53, and is smaller than the cut depth D of the cut 53. The minimum width H1 of the cut 53, the minimum width H2 of the protrusion 54, and the cut depth D of the cut 53 may be formed to be the same or different, and can be set appropriately, as long as they are larger than the outer periphery length (contact area of the side surface) of a simple rectangle. For example, the minimum width H2 of the protrusion 54 can be reduced to the same extent as the height T2 of the protrusion 54 from the back surface 12. In the example shown in FIG. 8, the width of the protrusion 44 is smaller than that of the protrusion 44 in the fourth example, so that when the tightening margin is the same, the compressive stress when the protrusion 50 is fitted into the recess 51 is higher, and further, the contact area of the outer periphery side surface between the protrusion 50 and the recess 51 can be made larger than that of a simple rectangle, so that the joining strength can be increased.

Next, the manufacturing method of the laminated product 1 will be explained with reference to the process flow diagram shown in Figure 9.

Figure 9 is a process flow explanatory diagram showing the manufacturing method of the laminated product 1. The first to fifth examples described above can be manufactured in the same process, although they have different shapes, so they will be explained with reference to Figure 1 along with the process flow explanatory diagram of Figure 8. Note that the manufacturing method of the laminated product 1 is a method in which each process is continuously performed by a progressive die. First, the through hole 15 of the metal plate member W8, which will be the bottom layer, is formed in the metal plate material W0, which is the raw material (step S1). Next, the outer shape of the metal plate member W8 of the bottom layer is punched out from the metal plate material W0 (step S2). Next, the recess 13 and the protrusion 14 of the metal plate member W7, which will be the upper layer of the metal plate member W8, are formed by half-punching (step S3). Next, the outer shape of the metal plate member W7 is punched out, and the protrusion 14 of the metal plate member W7 is fitted into the through hole 15 of the metal plate member W8 (step S4). Note that, here, fitting refers to fitting the protrusion 14 into the through hole 15 and pressing it in.

In this way, the metal plate member W7 is laminated on the lowermost metal plate member W8. Next, the concave portion 13 and the convex portion 14 of the metal plate member W6, which is the layer above the metal plate member W7, are formed in the metal plate material W0 by half-punching (step S5). Next, the outer shape of the metal plate member W6 is punched out from the metal plate material W0, and the convex portion 14 of the metal plate member W6 is fitted into the concave portion 13 of the lower metal plate member W7 (step S6). The steps S5 and S6 are also repeated for the metal plate members W5 to W1, which are the layers above the metal plate member W6. That is, the metal plate members W5 to W1 are formed by sequentially forming the concave portion 13 and the convex portion 14 of each layer of the metal plate member W in the metal plate material W0, punching out the outer shape, and fitting the convex portion 14 of the upper layer into the concave portion 13 of the lower layer to integrate them (step S7). Then, in the next step, it is determined whether a predetermined number of metal plate members W have been fitted (step S8). The laminated product 1 is integrated by fitting together a predetermined number of metal plate members W. Steps S1 to S8 are then repeated until the predetermined number is reached.

If the predetermined number of metal plate members W are not fitted in step S8 (NO), the steps of forming recesses 13 and protrusions 14 in the metal plate members W, punching out the outer shape, and fitting the protrusions 14 of the upper layer into the recesses 13 of the lower layer are repeated until the predetermined number is reached (step corresponding to step S7).

In the manufacturing method of the laminated product 1 described above, each process is performed continuously by a progressive die. In the manufacturing method using a progressive die, it is possible to simultaneously perform the process of punching out the outer shape of the lowermost metal plate member W8 (step S2) and the process of forming the recesses 13 and protrusions 14 of the upper metal plate member W7 (step S3). It is also possible to simultaneously perform the process of punching out the outer shape of the metal plate member W7 and fitting the protrusions 14 of the metal plate member W7 into the through holes 15 of the metal plate member W8 (step S4), and the process of forming the recesses 13 and protrusions 14 of the upper metal plate member W6 (step S5). Even in the metal plate member W above the metal plate member W6, it is possible to simultaneously perform the process of punching out the outer shape, the process of fitting the protrusions 14 into the recesses 13, and the process of forming the recesses 13 and protrusions 14 that will become the upper metal plate member W.

The laminated product 1 of the first example described above is integrated by fitting the convex portion 14 of the upper metal plate member W into the concave portion 13 of the lower metal plate member W. The convex portion 14 has a plurality of cut portions 21 formed inward from the circumference 20 or the four sides 24 of the rectangle 23, and has a protrusion portion 22 formed between adjacent cut portions 21. In the case where the concave portion 13 and the convex portion 14 are simply circular or rectangular as in the conventional technology described above, when the convex portion 14 of the upper metal plate member W is fitted into the concave portion 13 of the lower metal plate member W, the compressive force generated on the mutual contact side surfaces when the convex portion 14 of the upper metal plate member W is fitted into the concave portion 13 of the lower metal plate member W, among the compressive forces generated, the compressive force directed from the centroid P toward the outside of the concave portion 13 causes the outer periphery of the unregulated concave portion 13 of the metal plate member W to deform in the planar direction or bulge in the thickness direction, and sufficient bonding strength may not be obtained.

In the laminated product 1 of the first example, the convex portion 14 is composed of a plurality of cut portions 21 and protrusions 22. When the convex portion 14 of the upper metal plate member W is fitted into the recessed portion 13 of the lower metal plate member W, the compressive force generated on the contacting side of the two acts to pinch each of the protrusions 22, so that a sufficient bonding force can be obtained. In addition, the length of contact between the two when the convex portion 14 is fitted into the recessed portion 13, that is, the contact area of the outer peripheral side, is larger than when the recessed portion 13 and the convex portion 14 are simply circular or rectangular. Therefore, it is possible to increase the bonding strength between the upper metal plate member W and the lower metal plate member W. In the second to sixth examples, it is possible to increase the bonding strength for the same reason as in the first example. However, in the third example, the number of protrusions 22 is increased compared to the first example, so that the bonding force is higher than that of the first example. In the fifth example, the small protrusions 44a and 44b are provided on the protrusion 44, so that the bonding force is higher than that of the fourth example. From the above, it can be said that by increasing the number of protrusions 22, 32, 44, 54 in each example, it is possible to increase the bonding strength between the upper metal plate member W and the lower metal plate member W.

In addition, when the recess 13 of the lower metal plate member W and the protrusion 14 of the upper metal plate member W are fitted together, a tightening margin is provided around the entire circumference of the contacting sides. As a result, the contact area of the outer peripheral sides of the recess 13 and the protrusion 14 is larger than in the case of a simple circle or square, and the total compressive force generated on the outer peripheral sides when the protrusion 14 is fitted into the recess 13 is larger. This makes it possible to increase the bonding strength between the upper metal plate member W and the lower metal plate member W.

As shown in Figs. 2 and 3, the convex portion 14 of the first example has four cuts 21 and protrusions 22 at equal intervals (90 degree intervals) along the circumference 20. In addition, the convex portions 14 and 30 of the second example (see Fig. 4) and the third example (see Fig. 5) have six cuts 21 and protrusions 22 at equal intervals (60 degree intervals) along the circumference 20. By adopting such a configuration, it is possible to suppress the variation in the compressive force generated at each location when the upper convex portion 14 is fitted into the lower concave portion 13, thereby suppressing distortion during fitting and suppressing warping of the metal plate member W. In the fourth and fifth examples, which have a rectangular outer shape, the respective protrusions 44, 54 are provided at equal intervals in the circumferential direction, and therefore the same effect as the first and second examples can be obtained.

In the first and second examples, the bottom 21a of the cutout 21 is formed by an arc R1, and the top 22a of the protrusion 22 is formed by an arc R2. In the third example, the bottom 21a of the cutout 21 is formed by an arc R1, and the intersection of the outer periphery 33 and the straight line 32c is formed by a small-diameter arc R3. In the fourth example, the bottom 43a of the cutout 43 is formed by an arc R1, and the top 45 and corner 46 of the protrusion 44 are formed by an arc R4. In the fifth example, the bottom 53a of the cutout 53 is formed by an arc R5, and the top 55 of the protrusion 54 and the intersection of the cutout 53 and the side 52 are formed by an arc R6. In this way, the corners of each of the protrusions in the first to sixth examples are rounded with one of the circular arcs R1 to R6, which makes it possible to suppress stress concentration that occurs at the corners when each of the protrusions in the upper layer is fitted into each of the recesses in the lower layer, thereby making it possible to suppress damage. Furthermore, although not shown in the figures, it is possible to suppress damage caused by corners in the punch and die of the metal mold used in half-punching.

In addition, in the first to sixth examples, the depth T1 from the surface 11 of each recess is greater than the height T2 from the back surface 12 of each protrusion. With this configuration, when the upper metal plate member W and the lower metal plate member W are joined, a gap is created in the thickness direction between each recess in the lower layer and each protrusion in the upper layer, so that chips and the like generated during the fitting process can be absorbed by this gap, making it possible to closely adhere the upper metal plate member W and the lower metal plate member W.

The manufacturing method of the laminated product 1 is to first form a through hole 15 in the metal plate material W0, and punch out the metal plate member W8 that will be the bottom layer. Next, the concave portion 13 and the convex portion 14 of the upper layer metal plate member W7 are formed in the metal plate material W0, and then the outer shape of the metal plate member W7 is punched out, and the convex portion 14 of the metal plate member W7 is fitted into the through hole 15 of the bottom layer metal plate member W8. Then, for the metal plate members W6 to W1 that are above the metal plate member W7, the concave portion 13 and the convex portion 14 of the upper layer metal plate member W are formed in the metal plate material W0, the outer shape is punched out, and the convex portion 14 of the upper layer metal plate member W is fitted into the concave portion 13 of the lower layer metal plate member W. The laminated product 1 is formed by repeating the above process a predetermined number of times to integrate eight layers of metal plate members W.

According to this manufacturing method, the laminated product 1 is formed by a process of forming a through hole 15 in the bottom metal plate member W8, a process of half-punching the metal plate member W in the metal plate material W0, and a process of punching out the outer shape of the metal plate member W and fitting the convex portion 14 of the upper metal plate member W into the concave portion 13 of the lower metal plate member W. Each of these processes is composed of simple steps, and it is possible to significantly increase productivity compared to conventional manufacturing methods such as side welding or bonding of metal plate members, or manufacturing methods that include a reinforcement process using a punch or the like described in the patent document.

1...Laminated product, 10...Joint, 11...Surface, 12...Back, 13, 31, 41, 51...Concave, 14, 30, 40, 50...Convex, 15...Through hole, 20...Circumference (circumscribed circle), 21, 43, 53...Cut, 22, 32, 44, 54...Protrusion, 21a, 43a, 53a...Bottom of cut, 22a, 45, 55...Top of protrusion, 24, 42, 52...Side of rectangle, 25...Hexagon, 26...Hexagon Side, 32a, 32b...diagonal protrusion, 32c...straight line, 33...periphery, 42...side, 44a, 44b...small protrusion, 46, 56...corner, 47...circumscribed circle, D...depth of cut, 48...second cut, H1...minimum width of cut, H2...minimum width of protrusion, P...centre, R1-R6...circular arc, T0...thickness of metal plate member, T1...depth of recess (height of protrusion), W0...metal plate material, W, W1-W8...metal plate member

Claims (6)

A laminated product formed by laminating and integrating metal plate members,
the metal plate member has a recess formed on a front surface of the metal plate member by half-punching and a protrusion formed on a back surface of the metal plate member and capable of fitting into the recess,
the protruding portion has a plurality of cutouts formed inward from a circumference or a side of a polygon in a plan view,
The recess of one of the metal plate members is fitted into the protrusion of the other metal plate member to be integrated with the other metal plate member.
A laminated product characterized by: The laminated product according to claim 1,
when the recess of the metal plate member in the lower layer and the protrusion of the metal plate member in the upper layer are fitted together, a tightening margin is provided around the entire circumference of the contact side surfaces of the recess and the protrusion.
A laminated product characterized by: The laminated product according to claim 1,
A plurality of the cut portions are provided at equal intervals along the circumference.
A laminated product characterized by: The laminated product according to claim 1,
a bottom of the cutout, a top of a protrusion formed between adjacent cutouts, and a position connecting the cutout and the top are formed by a circular arc;
A laminated product characterized by: The laminated product according to claim 1,
The depth of the recess from the front surface is greater than the height of the protrusion from the back surface.
A laminated product characterized by: A step of forming a through hole having a shape conforming to the convex portion in a metal plate material that is to be the bottom layer;
punching out a metal plate member that will become the bottom layer from the metal plate material;
a step of forming, by half-punching, the convex portion having a substantially U-shaped notch portion formed inward from a side of a circumference or a polygon and a protrusion portion formed between adjacent notches, and a concave portion having a shape following the convex portion and into which the convex portion can be fitted;
punching out an outer shape of the metal plate member that will be the layer immediately above the bottom layer from the metal plate material on which the recesses and the protrusions are formed, and fitting the protrusions into the through holes;
forming the recesses and the protrusions of the metal plate member which is an upper layer of the metal plate member which is the upper layer on the metal plate material;
punching out the outer shape of the metal plate member of the further upper layer and fitting the convex portion of the upper layer into the concave portion of the lower layer,
forming the recesses and the protrusions until a predetermined number is reached; punching out the outer shape of the metal plate member that will become the upper layer, and fitting and integrating the protrusions of the upper layer into the recesses of the lower layer;
A method for producing a laminated product comprising the steps of:

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