Rebound material for die cutting

Abstract

The present invention provides a die-cutting resilience material that allows for full flexibility of the contact area and prevents the protrusion from easily coming out of the fitting hole even when the size of the fitting hole is smaller than that of conventional dies. [Solution] The die-cutting rebound material 1 of the present invention is made of a plastic elastic member and comprises a substantially rectangular parallelepiped contact portion 2 having two recesses 2e each on a first side surface 2c and a second side surface 2d that are parallel to each other, and a pair of semi-cylindrical projections 3, 3 that are provided on the lower surface 2b of the contact portion 2 so as to protrude downward.

Description

Technical Field

[0001] The present invention relates to a resilient material installed in a die for the purpose of enhancing the mold release property of a product when punching is performed using the die. In particular, the present invention relates to a resilient material for a die in which a contact portion is easily deformed and the size of a fitting hole provided in the die can be made smaller than in the conventional case.

Background Art

[0002] Regarding dies used for punching sheet materials such as paper and cardboard and foams such as urethane, in addition to the Thomson type (flat type), a rotary type used for a rotary die cutter is known. As shown in FIG. 8(a), a die 50a called a Thomson type (flat type) has a resilient material made of urethane, sponge, etc. disposed along a metal cutting blade 52a embedded in a groove (not shown) formed in a base 51a made of a veneer board, resin board, metal board, etc. Then, when this die 50a moves the base 51a in a direction away from the sheet material after a portion of the sheet material that abuts against the cutting edge of the cutting blade 52a is punched in the shape of the cutting blade 52a as the resilient material is compressed and deformed, the sheet material is detached from the cutting blade 52a by the shape of the resilient material elastically recovering. Further, as shown in FIG. 8(b), a die 50b used for a rotary die cutter (not shown) having a die cylinder and an anvil cylinder installed in parallel and rotating in opposite directions to each other is made of a veneer board, resin board, metal board, etc., and has a structure in which a metal cutting blade 52b is embedded in a groove (not shown) formed in a base 51b having an arc-shaped cross section. [[ID=I8]]

[0003] The resilient material has a function of enhancing the mold release property of the product and is indispensable for the dies 50a and 50b. However, since the conventional resilient material was attached to the surfaces of the bases 51a and 51b using double-sided tape or the like, it was difficult to remove the resilient material from the dies 50a and 50b and reuse it after use. To address these challenges, for example, Patent Document 1 discloses an invention related to a die-cutting rebound material, titled "Die-cutting rebound material and die in which the same is used," which has appropriate elasticity, is less likely to cause dents or deformation to sheet materials and foams such as urethane, is easy to attach to and detach from the base, and can be reused by removing it from the base after use of the die-cutting. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Patent No. 7223383 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The invention relating to the die-cutting rebound material disclosed in Patent Document 1 has a structure comprising a contact portion made of an elastic material such as polyethylene foam, urethane, or elastomer resin, and a cylindrical projection provided on the lower surface of the contact portion so as to protrude downward and to be removablely fitted into the fitting hole of the die. Although the die-cutting rebound material can be easily removed from the die by removing the projection from the fitting hole, there was a problem that if the diameter of the projection was reduced in order to reduce the size of the fitting hole of the die, the projection would easily come out of the fitting hole. Furthermore, in this invention, depending on how the recesses on the side surfaces of the contact portion are provided, the flexibility of the contact portion may not be fully exhibited. The present invention has been made to address these problems, and aims to provide a die-cutting rebound material that allows for sufficient flexibility of the contact portion and prevents the protrusion from easily coming out of the fitting hole even when the size of the fitting hole is smaller than that of a die-cutting die using the conventional die-cutting rebound material disclosed in Patent Document 1. [Means for solving the problem]

[0006] To achieve the above objective, the first invention is a die-cutting rebound material made of a plastic elastic member, which is installed on a die along a cutting blade in a die in which a cutting blade is embedded in a groove formed in a plate-shaped base, and comprises a contact portion whose upper surface is formed flat so as to be parallel to the mounting surface that contacts the base, and a recess provided on the side surface between the mounting surface and the upper surface, and a pair of projections on the mounting surface of the contact portion which project downward and are formed to be fitted into a fitting hole provided in the die, and which are semi-cylindrical or semi-cylindrical in shape, wherein the projections have a first projection side surface whose cross-sectional contour line is arc-shaped and a second projection side surface whose cross-sectional contour line is straight, and the die is characterized in that a fitting hole is provided in the base such that the cross-section is elongated, and a thin plate-shaped engaging portion projects laterally from the first projection side surface and is provided so that the projection can be fitted into the fitting hole by elastic deformation. Furthermore, in the first invention, "a pair of semi-cylindrical or semi-cylindrical projections" also includes "a pair of projections that are roughly semi-cylindrical or roughly semi-cylindrical."

[0007] The second invention is characterized in that, in the first invention, the pair of protrusions are such that the side surface of one second protrusion is positioned close to the first tangent plane of the other first protrusion side surface, and the side surface of the other second protrusion is positioned close to the second tangent plane of the one first protrusion side surface.

[0008] The third invention is characterized in that, in the first invention, the pair of projections are connected to each other via a connecting member at the base end sides of the first projection.

[0009] The fourth invention is characterized in that, in the third invention, the connecting member is formed to be insertable into a fitting hole together with a pair of protrusions.

[0010] The fifth invention is characterized in that, in any of the first to fourth inventions, the side surface of the rectangular parallelepiped contact portion has a first side surface and a second side surface that are parallel to each other, the recess consists of a first recess provided on the first side surface and a second recess provided on the second side surface, and when the contact portion is viewed from the top side in a state in which the contact portion is cut across the first recess and the second recess by a virtual plane parallel to the top surface, the first recess and the second recess are arranged alternately. [Effects of the Invention]

[0011] In the first invention, compared to the case where a die-cutting rebound material equipped with a cylindrical or cylindrical projection is used, the width of the fitting hole provided in the die can be reduced by approximately half. Therefore, even in locations where it was previously not possible to provide a fitting hole for inserting a cylindrical or cylindrical projection due to the narrow spacing between the two grooves into which the cutting blade is embedded and the risk of the base cracking if a fitting hole for inserting a cylindrical or cylindrical projection was provided, it is now possible to provide a fitting hole with approximately half the width to create a contact area. Furthermore, since the pair of protrusions in the first invention correspond to a conventional cylindrical or cylindrical protrusion divided in half, the number of engaging portions provided on them remains the same as in the case of a conventional cylindrical or cylindrical protrusion. Therefore, according to the first invention, the width of the fitting hole to be provided in the die can be set narrower without reducing the engaging force of the protrusions with respect to the fitting hole in the die.

[0012] Even when the two second protrusions of a pair of protrusions are arranged in the same plane, the width of the fitting hole to be provided in the die can be set to be narrower than the diameter of the protrusion. However, in this case, the engaging portion provided on each of the pair of protrusions will engage with only one of the pair of inner wall surfaces of the fitting hole, and the engagement state between the protrusion and the fitting hole may not be stable. In contrast, in the second invention, when the pair of protrusions are inserted into the fitting hole of the die, the two second protrusions are positioned close to the pair of inner wall surfaces of the fitting hole, and each engaging portion engages with the pair of inner wall surfaces of the fitting hole. Therefore, in addition to the effects of the first invention, the second invention provides the effect of stabilizing the engagement state between the protrusion and the fitting hole.

[0013] When a pair of protrusions are inserted into the fitting hole of the die, if deformation occurs such that their tips tilt toward each other, the engagement between the fitting hole of the die and the protrusions becomes insufficient, and there is a risk that the protrusions may easily come out of the fitting hole. In contrast, in the third invention, the sides of the first protrusions at the base end of the pair of protrusions are connected to each other via a connecting member, and the connecting member acts to prevent the above-mentioned deformation. Therefore, according to the third invention, in addition to the effects of the first invention, the protrusions engage sufficiently with the fitting hole of the die.

[0014] In the fourth invention, when the pair of projections are inserted into the fitting hole, the connecting member also engages with the fitting hole together with the engaging portion, thus further enhancing the effect of the third invention, in which the projections engage sufficiently with the fitting hole of the die.

[0015] In the fifth invention, when the contact portion is cut by a virtual plane parallel to the upper surface, the portion of the contact portion that does not have the first recess and the second recess acts as a rib that generates resistance to deformation. This rib is composed of a first rib parallel to the first and second sides of the contact portion and a second rib extending from this first rib. On the other hand, when the first recess and the second recess are not alternately provided with respect to the first side surface and the second side surface like the contact portion in the conventional ejection mold cushion material, a portion where the above-described first rib and the second rib cross to form a cross occurs. And since this portion acts to increase the resistance against deformation of the contact portion, it becomes difficult for the contact portion to deform. Conversely, in the fifth invention, since the contact portion is more easily deformed than the contact portion in the conventional ejection mold cushion material, the buffering effect of the contact portion is sufficiently exhibited.

Brief Description of Drawings

[0016] [Figure 1] It is an external perspective view of an ejection mold cushion material according to an embodiment of the present invention. [Figure 2] (a) is a front view of the ejection mold cushion material shown in FIG. 1, and (b) is a cross-sectional view taken along the line A-A in FIG. (a). [Figure 3] (a) is a front view of an ejection mold cushion material according to the prior art, and (b) is a cross-sectional view taken along the line B-B in FIG. (a). [Figure 4] (a) and (b) are views of the lower surface of the contact portion in the ejection mold cushion material shown in FIG. 1 and a modified example thereof as seen from the side of the protrusion. [Figure 5] (a) and (b) are each a plan view showing a part of an ejection mold (Thomson type) in which the ejection mold cushion material shown in FIGS. 2(a) and 3(a) is installed. [Figure 6] (a) and (b) are respectively a view taken in the direction D in FIG. 3(a) and a view taken in the direction C in FIG. 2(a). [Figure 7] (a) and (b) are each an external perspective view of an ejection mold (Thomson type and rotary type) in which the ejection mold cushion material shown in FIG. 1 is installed. [Figure 8] (a) and (b) are each an external perspective view of an ejection mold called Thomson type (flat type) and rotary type.

Embodiments for Carrying Out the Invention

[0017] <元素符号: The structure of the ejection mold rebound material of the present invention, as well as the functions and effects exerted based thereon, will be specifically described while referring to FIGS. 1 to 7. In addition, since the ejection mold rebound material of the present invention is attached to the base of the ejection mold used for punching sheet materials and foams such as urethane, in the following description, the side in contact with the sheet material and the side in contact with the base in the state of being attached to the base are respectively expressed as the "upper surface" and the "lower surface", and the base side is expressed as the "lower side".

Example

[0018] The ejection mold rebound material of the present invention will be described with reference to FIGS. 1 and 2. In FIG. 1, in order to avoid complication of the figure, only some engaging portions 4 are labeled. As shown in FIGS. 1, 2(a) and 2(b), the ejection mold rebound material 1 of the present invention is made of an elastic member made of plastic such as a polyethylene foam, urethane, or an elastomer resin, and has a substantially rectangular parallelepiped-shaped contact portion 2 provided with two concave portions 2e each with respect to the first side surface 2c and the second side surface 2d that are parallel to each other, and a pair of protruding portions that are provided so as to protrude downward from the lower surface 2b of the contact portion 2 and have a semi-cylindrical shape.

[0019] On the upper surface 2a of the contact portion 2 that is formed flat so as to be parallel to the lower surface 2b, minute irregularities 2f are provided to reduce the frictional force generated between the contact portion 2 and the sheet material and make it easier for the sheet material to separate during mold release. In addition, on the first protruding portion side surface 3a of the protruding portion 3 whose cross-sectional contour line is arc-shaped, a thin plate-shaped engaging portion 4 is provided so as to protrude sideways, and on the second protruding portion side surface 3b of the protruding portion 3 whose cross-sectional contour line is linear, a rod-shaped reinforcing portion 5 having a predetermined length along the axial direction of the protruding portion 3 is provided. Further, the pair of protruding portions are connected to each other via a plate-shaped connecting member 6 on the first protruding portion side surfaces 3a on the proximal end side (the side closer to the lower surface 2b of the contact portion 2). In addition, the engaging portion 4 is composed of three flange portions 4a to 4c provided at a predetermined interval in the axial direction of the protruding portion 3 with respect to the first protruding portion side surface 3a.

[0020] As shown in Figure 2(b), the recess 2e consists of a first recess 16a provided on the first side surface 2c of the contact portion 2 and a second recess 16b provided on the second side surface 2d. In the die-cutting resilience material 1, when the contact portion 2 is viewed from the upper surface 2a side in a state where the contact portion 2 is cut across the first recess 16a and the second recess 16b by a virtual plane parallel to the upper surface 2a, the first recess 16a and the second recess 16b are arranged alternately, and the portion of the contact portion 2 in which the first recess 16a and the second recess 16b are not provided functions as a rib that generates resistance to deformation. As shown in Figure 2(b), the ribs described above consist of a first rib 2g parallel to the first side surface 2c and the second side surface 2d, and a second rib 2h extending from the first rib 2g. However, unlike the first rib 8f and the second rib 8g described later, there is no intersection between the first rib 2g and the second rib 2h.

[0021] Next, an example of the structure of a conventional die-cutting rebound material will be explained using Figures 3(a) and 3(b). As shown in Figures 3(a) and 3(b), the conventional die-cutting rebound material 7 is made of an elastic plastic member such as polyethylene foam, urethane, or elastomer resin, and comprises a substantially rectangular parallelepiped contact portion 8 with four recesses 8e each on a first side surface 8c and a second side surface 8d that are parallel to each other, and a cylindrical projection 9 that is provided on the lower surface 8b of the contact portion 8 so as to protrude downward. Furthermore, the upper surface 8a of the contact portion 8 is formed flat so as to be parallel to the lower surface 8b, and a thin plate-shaped engaging portion 10 is provided on the side surface 9a of the projection 9 so as to protrude laterally. The engaging portion 10 is composed of three flange-shaped portions 10a to 10c, which are provided on the side surface 9a of the projection 9 at predetermined intervals in the axial direction.

[0022] As shown in Figure 3(b), the recess 8e consists of a first recess 17a provided on the first side surface 8c of the contact portion 8 and a second recess 17b provided on the second side surface 8d. In the die-cutting rebound material 7, when the contact portion 8 is viewed from the upper surface 8a side in a state where the contact portion 8 is cut by a virtual plane parallel to the upper surface 8a so as to cross the first recess 17a and the second recess 17b, the first recess 17a and the second recess 17b are not arranged alternately, and the portion of the contact portion 8 that does not have the first recess 17a and the second recess 17b functions as a rib that generates resistance to deformation of the contact portion 8. As shown in Figure 3(b), the ribs described above are composed of a first rib 8f parallel to the first side surface 8c and the second side surface 8d, and a second rib 8g perpendicular to it. However, the first rib 8f and the second rib 8g intersect in a cross shape, and this portion acts to increase the resistance to deformation of the contact portion 8. Therefore, the contact portion 8 is less prone to deformation than the contact portion 2. Conversely, it can be said that the contact portion 2 of the die-cutting rebound material 1 is more easily deformed than the contact portion 8 of the die-cutting rebound material 7. As a result, the cushioning effect of the contact portion 2 is fully realized in the die-cutting rebound material 1 compared to the contact portion 8 of the die-cutting rebound material 7.

[0023] The shape of the pair of protrusions 3, 3 will be explained in more detail using Figures 4(a) and 4(b). Figure 4(a) is a view in the direction of arrow C in Figure 2(a), and Figure 4(b) is a view of the die-cutting rebound material 1a, which is a modified example of the die-cutting rebound material 1, from the same direction as Figure 4(a). The thick dashed lines shown in Figures 4(a) and 4(b) represent the outlines of the fitting holes 11 and 11a of the die, in which the die-cutting rebound materials 1 and 1a are installed, respectively. As shown in Figures 4(a) and 4(b), the contour lines of the fitting holes 11 and 11a are elongated holes in which the ends of the two long sides constituting a rectangle are connected to each other via semicircles. Therefore, the fitting holes 11 and 11a have a pair of inner wall surfaces 12a, 12a that are parallel to each other (see Figure 7(a)) and a pair of inner wall surfaces 12b, 12b whose contour lines are semicircular (see Figure 7(a)).

[0024] As shown in Figure 4(a), the pair of protrusions 3, 3 of the die-cutting rebound material 1 are arranged such that the second protrusion side surface 3b of one protrusion 3 is positioned close to the first tangent plane 14a of the first protrusion side surface 3a (see Figure 2(a)) of the other protrusion 3, and the second protrusion side surface 3b of the other protrusion 3 is positioned close to the second tangent plane 14b of the first protrusion side surface 3a (see Figure 2(a)) of the one protrusion 3. In conventional die-cutting rebound material 7, the width of the fitting hole (the diameter of the fitting hole 11b shown in Figure 5(b)) must be wider than the diameter of the projection 9. However, in the die-cutting rebound material 1 with the above structure, the distance L1 between the first tangent surface 14a and the second tangent surface 14b is approximately half the diameter of the projection 3. Therefore, the width W1 of the fitting hole 11 (the distance between the pair of inner wall surfaces 12a, 12a) can be made narrower than the diameter of the projection 3. As a result, when the diameters of the projection 3 and the projection 9 are the same, the width W1 of the fitting hole 11 in the die in which the die-cutting rebound material 1 is installed is narrower than the width of the fitting hole in the die in which the conventional die-cutting rebound material 7 is installed (the diameter of the fitting hole 11b shown in Figure 5(b)). Furthermore, even if the second projection sides 3b, 3b of the pair of projections 3, 3 are arranged in the same plane, the width W1 of the fitting hole 11 (the distance between the pair of inner wall surfaces 12a, 12a) can be set to be narrower than the diameter of the projection 3. However, in this case, the engaging parts 4 provided on each of the pair of projections 3, 3 will engage with only one of the pair of inner wall surfaces 12a, 12a of the fitting hole 11, which may result in an unstable engagement state between the projection 3 and the fitting hole 11, and is therefore undesirable. In contrast, in the die-cutting rebound material 1, when the pair of projections 3, 3 are inserted into the fitting hole 11 of the die, the second projection sides 3b of both are positioned close to the pair of inner wall surfaces 12a, 12a of the fitting hole 11, and each engaging part 4 engages with the pair of inner wall surfaces 12a, 12a of the fitting hole 11. Therefore, the die-cutting rebound material 1 has the unique effect of stabilizing the engagement state between the projection 3 and the fitting hole 11.

[0025] Thus, with the die-cutting rebound material 1, compared to the case where a die-cutting rebound material equipped with a cylindrical or cylindrical projection (for example, see die-cutting rebound material 7 shown in Figure 3(a)) is used, the width of the fitting holes provided in the die 50a, 50b (see Figures 8(a) and 8(b)) can be reduced by approximately half (for example, corresponding to the distance between the pair of inner wall surfaces 12a, 12a shown in Figure 7(a)). Therefore, as will be described later using Figures 5(a) and 5(b), the cutting blades 52a, 52b (see Figures 8(a) and 8(b)) can be reduced by approximately half. Even in locations where it was previously impossible to provide fitting holes for inserting the aforementioned protrusions, such as the narrow spacing between the two grooves 15 (see Figure 5(a) or Figure 5(b)) into which the protrusions are embedded, and the risk of the bases 51a and 51b (see Figures 8(a) and 8(b)) cracking if fitting holes for inserting the cylindrical or cylindrical protrusions were provided, it is now possible to provide fitting holes 11 with approximately half the width of the original fitting holes to install the contact portion 2. Furthermore, since the pair of protrusions 3, 3 correspond to a conventional cylindrical or cylindrical protrusion divided in half, the number of engaging portions 4 provided on them remains the same as in the case of a conventional cylindrical or cylindrical protrusion. Therefore, with the die-cutting rebound material 1, the width of the fitting hole 11 to be provided in the die can be set narrower without reducing the engagement force of the protrusions 3 with respect to the fitting hole 11 of the die.

[0026] Furthermore, if deformation occurs in which the tips of the pair of protrusions 3, 3 tilt toward each other when the pair of protrusions 3, 3 are inserted into the fitting hole 11 of the die, the engagement between the fitting hole 11 of the die and the protrusions 3 will be insufficient, and the protrusions 3 may easily come out of the fitting hole 11. In contrast, in the die-cutting rebound material 1, as already explained, the first protrusion sides 3a on the base end side (the side closer to the lower surface 2b of the contact portion 2) of the pair of protrusions 3, 3 are connected to each other via a connecting member 6. Therefore, as shown in Figure 4(a), when the pair of protrusions 3, 3 are inserted into the fitting hole 11 of the die, deformation in which the tips of the pair of protrusions 3, 3 tilt toward each other is prevented by the connecting member 6. Thus, the die-cutting rebound material 1 has the effect of ensuring that the protrusions 3 engage sufficiently with the fitting hole 11 of the die. Furthermore, as shown in Figure 4(a), the connecting member 6 is formed to be insertable into the fitting hole 11 together with the pair of projections 3, 3. Therefore, in the die-cutting rebound material 1, when the pair of projections 3, 3 are inserted into the fitting hole 11, the connecting member 6 engages with the fitting hole 11 together with the engaging portion 4. This increases the engagement force of the projections 3 with respect to the fitting hole 11, thereby further enhancing the effect of the projections 3 engaging sufficiently with the fitting hole 11 of the die.

[0027] In the case of a die-cutting rebound material 1a in which the second projection side surface 3b of one projection 3 is not positioned close to the first tangent plane 14a of the other first projection side surface 3a (see Figure 2(a)), for example, as shown in Figure 4(b), if the distance L2 between the first tangent plane 14a and the second tangent plane 14b is approximately equal to the diameter of the projection 3, then the width W2 (distance between the pair of inner wall surfaces 12a, 12a) of the fitting hole 11a of the die in which the die is installed will be approximately the same as the width of the fitting hole of the die in which a conventional die-cutting rebound material 7 is installed (the diameter of the fitting hole 11b shown in Figure 5(b)). As previously mentioned, the die-cutting rebound material 1 allows the width W1 of the die-cutting fitting hole 11 (see Figure 4(a)) to be narrower than the width of the die-cutting fitting hole in the conventional die-cutting rebound material 7 (the diameter of the fitting hole 11b shown in Figure 5(b)).

[0028] Next, the advantages of narrowing the width of the fitting hole in the die will be explained using Figures 5(a) and 5(b). Figures 5(a) and 5(b) are plan views showing a portion of the die 13 in which the die-cutting rebound material 1 is installed and a portion of the die 13a in which the conventional die-cutting rebound material 7 is installed, respectively. In die-cutting rebound material 1 and die-cutting rebound material 7, where the diameter of projection 3 and projection 9 are the same, as shown in Figures 5(a) and 5(b), if the spacing L3 between the pair of grooves 15, 15 into which the cutting blade 52a is embedded is the same in the die 13 in which die-cutting rebound material 1 is installed and in the die 13a in which die-cutting rebound material 7 is installed, then, as described above, the width W1 of the fitting hole 11 in die-cutting rebound material 13 (see Figure 4(a)) can be made narrower than the width of the fitting hole 11b in die 13a in which die-cutting rebound material 7 is installed (the diameter of the fitting hole 11b shown in Figure 5(b)). In Figure 5(b), in the area enclosed by the dashed line, a fitting hole 11b is provided near the groove 15 into which the cutting edge 52a is embedded. Therefore, in the die 13a, there is a risk that the base 51a may crack at that location. In contrast, in the die 13 shown in Figure 5(a), there is no fitting hole 11 near the groove 15 into which the cutting blade 52a is embedded, so there is no risk of the base 51a cracking near the groove 15. Therefore, with the die-cutting rebound material 1, even in places where it was previously not possible to provide a fitting hole 11b because the distance between the two grooves 15, 15 into which the cutting blade 52a is embedded in the die 13 is narrow and providing a fitting hole 11b of the conventional size would risk the base cracking, a fitting hole 11 can be provided and a contact portion 2 can be installed, thus providing greater design flexibility for the die 13.

[0029] The shapes of the engaging portion 10 of the die-cutting rebound material 7 and the engaging portion 4 of the die-cutting rebound material 1 will be explained using Figures 6(a) and 6(b). Figures 6(a) and 6(b) are views taken in the direction of arrow D in Figure 3(a) and in the direction of arrow C in Figure 2(a), respectively. As shown in Figure 6(a), the flange portions 10a to 10c that constitute the engaging portion 10 of the die-cutting rebound material 7 have a structure in which four circular notches are cut out when viewed perpendicular to the lower surface 8b of the contact portion 8, in order to facilitate deformation. Specifically, they have a shape that protrudes in four directions in a roughly cross shape. On the other hand, the flange portions 4a to 4c that constitute the engaging portion 4 of the die-cutting rebound material 1 are not simply cut in half by a plane containing the axis of the projection 9 of the die-cutting rebound material 7, but rather the projection 9 and flange portions 10a to 10c are cut in half by the aforementioned plane while flange portion 10b is rotated 90 degrees relative to flange portions 10a and 10c around the axis of the projection 9.

[0030] If the projection 3 and flange portions 4a-4c of the die-cutting rebound material 1 correspond to a structure in which the projection 9 and flange portions 10a-10c of the die-cutting rebound material 7 are simply cut in half by the plane, then when the projection 3 and flange portions 4a-4c of the die-cutting rebound material 1 are viewed perpendicular to the lower surface 2b of the contact portion 2, the notched portions of the flange portions 4a-4c will coincide. Therefore, when the projection 3 is inserted into the fitting hole 11 of the die, the engaging portion 4 may not engage sufficiently with the fitting hole 11. In contrast, if the projection 3 and flange portions 4a-4c of the die-cutting rebound material 1 correspond to a structure in which the flange portion 10b of the die-cutting rebound material 7 is rotated 90 degrees relative to the flange portions 10a and 10c around the axis of the projection 9, and the projection 9 and flange portions 10a-10c are cut in half by the plane, then as shown in Figure 6(b), when viewing the flange portions 4a-4c of the die-cutting rebound material 1 in a direction perpendicular to the lower surface 2b of the contact portion 2, the notched portions of flange portions 4a and 4c and flange portion 4b do not coincide, and the protruding portions of flange portions 4a and 4c are positioned at the notched portion of flange portion 4b. Therefore, in the die-cutting rebound material 1, when the projection 3 is inserted into the fitting hole 11 of the die, the engaging portion 4 engages sufficiently with the fitting hole 11.

[0031] The structure of the die (Thomson type and rotary type) on which the die-cutting rebound material 1 is installed will be explained using Figures 7(a) and 7(b). As shown in Figures 7(a) and 7(b), the die cutters 13 and 13b on which the die-cutting rebound material 1 is used have grooves (not shown) formed in the bases 51a and 51b, which are made of plywood, resin, metal, etc., by laser processing or the like. Metal cutting blades 52a and 52b, bent to the same shape as the grooves, are embedded in these grooves, and fitting holes 11 are provided along the cutting blades 52a and 52b for fitting the projections 3 of the die-cutting rebound material 1. Furthermore, the die-cutting rebound material 1 is designed so that the projection 3 can be inserted into the fitting hole 11 by the elastic deformation of the engaging portion 4. The engaging portion 4 elastically deforms to fill the gap between the first projection side surface 3a of the projection 3 and the inner wall surfaces 12a and 12b of the fitting hole 11, thereby generating a large frictional force between the projection 3 and the fitting hole 11. Therefore, with the die-cutting rebound material 1, there is no risk of the projection 3 unintentionally coming out of the fitting hole 11 of the base 51a and 51b after it has been installed in the die 13.

[0032] The contact portion 2 of the die-cutting rebound material 1 becomes a mounting surface where the lower surface 2b (see Figures 1(a) and 1(b)) contacts the bases 51a, 51b when it is installed on the die 13. At this time, the upper surface 2a (see Figure 1), which is formed flat so as to be parallel to the lower surface 2b, is parallel to the base 51a. In a die-cutting rebound material 1 with this structure, the upper surface 2a of the contact portion 2 with the sheet material is flat, and when installed in the die 13, the upper surface 2a of the contact portion 2 is parallel to the base 51a. As a result, when the sheet material is punched out by the die 13, the contact area between the upper surface 2a of the contact portion 2 and the sheet material is increased. This ensures that even if the surface of the sheet material is uneven, the pressing force from the die-cutting rebound material 1 to the sheet material is applied evenly during punching. Therefore, when the die-cutting rebound material 1 is used in the die 13, the punching force from the die 13 is not concentrated on a part of the sheet material, making it less likely for indentations to be left on the sheet material after punching. Furthermore, in the die-cutting rebound material 1, the elasticity of the contact area 2 can be changed by altering the shape, size, or number of recesses 2e. In other words, the die-cutting rebound material 1 has a structure that allows for easy adjustment of the elasticity of the contact area 2 by altering the shape, size, or number of recesses 2e, without changing the material of the contact area 2. Therefore, the die-cutting rebound material 1 can improve the release properties of the product by adjusting the elasticity of the contact area 2. Furthermore, the die-cutting rebound material 1 is fixed to the base 51a by inserting the projection 3 into the fitting hole 11, and this fixed state is released by pulling the projection 3 out of the fitting hole 11, thus making it easy to attach to and detach from the die-cutting die 13. The die-cutting rebound material 1 removed from the die-cutting die 13 can be reused.

[0033] As shown in Figure 7(b), the die 13b in which the die-cutting rebound material 1 is used in a rotary die cutter (not shown) equipped with a die cylinder and an anvil cylinder that are installed in parallel and rotate in opposite directions. The die 13b is made of plywood, resin plate, metal plate, etc., and has a base 51b with an arc-shaped cross-section in which a metal cutting blade 52b is embedded in a groove. A fitting hole 11a for inserting the projection 3 of the die-cutting rebound material 1 is provided along the cutting blade 52b. In other words, the die 13b has a structure in which the fitting hole 11a is provided where the die-cutting rebound material 1 is installed in the conventional die 50b (see Figure 8(b)). Furthermore, in the die-cutting rebound material 1, the projection 3 is structured to be insertable into the fitting hole 11a by the elastic deformation of the engaging portion 4. The engaging portion 4 has the effect of generating a large frictional force between the projection 3 and the fitting hole 11a by elastically deforming to fill the gap between the first projection side surface 3a of the projection 3 and the inner wall surfaces 12a and 12b of the fitting hole 11a. Therefore, in the die-cutting rebound material 1, there is no risk of the projection 3 unintentionally coming out of the fitting hole 11a of the base 51b after it has been installed in the die 13b. In addition, some fitting holes 11a have a circular cross-section. For such fitting holes 11a, it is desirable to use a die-cutting rebound material 1 in which the cross-section of the lower surface 2b of the contact portion 2 is arc-shaped.

[0034] The die-cutting rebound material of the present invention is not limited to the structure shown in the above-described embodiment. For example, instead of recesses 2e being provided on the first side surface 2c and the second side surface 2d of the contact portion 2, the die-cutting rebound material 1 may have a hole that penetrates from the first side surface 2c to the second side surface 2d, or it may have a structure in which recesses 2e are provided on only one of the first side surface 2c and the second side surface 2d, or it may have a structure in which recesses 2e are provided on sides other than the first side surface 2c and the second side surface 2d. Furthermore, the projection 3 can be a separate component from the contact portion 2, with the upper surface of the projection 3 joined to the lower surface 2b of the contact portion 2. In addition, the projection 3 may have a cylindrical shape instead of a columnar shape, or it may have a prismatic or rectangular tube shape. [Industrial applicability]

[0035] The die-cutting rebound material of the present invention is installed in die-cutting molds called Thomson type or rotary type, whose base is formed from plywood, resin plate, or metal plate, and can be used when die-cutting sheet materials such as paper and corrugated cardboard, as well as foams such as urethane. [Explanation of Symbols]

[0036] 1, 1a…Rebound material for die cutting 2…Contact part 2a…Top surface 2b…Bottom surface 2c…First side surface 2d…Second side surface 2e…Recess 2f…Rubber 2g…First rib 2h…Second rib 3…Protrusion 3a…Side surface of first protrusion 3b…Side surface of second protrusion 4…Engaging part 4a~4c…Flange part 5…Reinforcement part 6…Connecting member 7…Rebound material for die cutting 8…Contact part 8a…Top surface 8b…Bottom surface 8c…First side surface 8d…Second side surface 8e…Recess 8f…First rib 8g…Second rib 9…Protrusion 9a…Side surface 10…Engaging part 10a~10c…Flange part 11, 11a, 11b…Matching hole 12a, 12b…Inner wall surface 13, 13a, 13b…Die-cutting die 14a…First tangent plane 14b…Second tangent plane 15…Groove 16a, 17a…First recess 16b, 17b…Second recess 50a, 50b…Die-cutting die 51a, 51b…Base 52a, 52b…Cutting blade L1~L3…Spacing W1, W2…Width

Claims

1. A die-cutting rebound material made of an elastic plastic member, which is installed on the base along the cutting blade in a die-cutting die in which a cutting blade is embedded in a groove formed in the plate-shaped base, The upper surface is formed flat so as to be parallel to the mounting surface that contacts the base, and a recess is provided on the side surface between the mounting surface and the upper surface of the contact portion, The mounting surface of this contact portion is provided with a pair of projections that protrude downward and are formed to be insertable into fitting holes provided in the die, and are semi-cylindrical or semi-transparent in shape. The projection has a first projection side surface whose cross-sectional contour is arc-shaped, and a second projection side surface whose cross-sectional contour is straight. The aforementioned die has a fitting hole provided in the base such that its cross-section is elongated. The die-cutting rebound material is characterized in that a thin plate-shaped engaging portion protrudes laterally from the side surface of the first projection, and the projection is provided so as to be insertable into the fitting hole by elastic deformation.

2. The die-cutting rebound material according to claim 1, characterized in that the pair of projections are such that one side surface of the second projection is positioned close to the first tangent plane of the other side surface of the first projection, and the other side surface of the second projection is positioned close to the second tangent plane of the one side surface of the first projection.

3. The die-cutting rebound material according to claim 1, characterized in that the pair of projections are connected to each other via a connecting member at the base end of the first projection.

4. The die-cutting rebound material according to claim 3, characterized in that the connecting member is formed to be insertable into the fitting hole together with the pair of protrusions.

5. The side surfaces of the contact portion, which is shaped like a rectangular parallelepiped, have a first side surface and a second side surface that are parallel to each other. The recess consists of a first recess provided on the first side surface and a second recess provided on the second side surface. The die-cutting rebound material according to any one of claims 1 to 4, characterized in that when the contact portion is viewed from the upper surface side in a state in which the contact portion is cut across the first recess and the second recess by a virtual plane parallel to the upper surface, the first recess and the second recess are arranged alternately.

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