Punching chip extrusion tool and sheet trimming mold using the same

Abstract

To provide a punching chip extrusion tool capable of being simplified in a structure, and achieving punching processing such as, forming of an extremely narrow slender hole and a slender notch and the like on a sheet, the tool being used for a sheet trimming mold.SOLUTION: A punching chip extrusion tool comprises: a movable member 11 which is arranged in an interior gap 4 of a punching blade 3 in a sheet trimming mold T in a manner of capable of moving in a blade height direction; a spring member 12 which is continuous to the movable member, protrudes in a blade thickness direction so as to freely deform elastically in the blade height direction, and is loosely fitted to a side hole 3b which is provided by drilling, on a side face of the punching blade 3; and a terminal member 13 continuous to the spring member, and extends to the interior gap 4 of the punching blade 3 in a manner of extending from the side hole 3b to a blade root direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a scrap pusher that is installed in the inner gap of a punching blade when punching a sheet such as cardboard, and that pushes scraps that have entered the inner gap of the punching blade when the punching blade cuts into the sheet during the punching operation back to the original position on the sheet when the punching blade separates from the sheet in preparation for the next punching operation, and a sheet punching die using the same. [Background technology]

[0002] When the next punching operation is performed while the scraps generated in the punching operation remain in the inner gap of the punching blade, new scraps get into the inner gap of the punching blade. If this process is repeated, the punching blade will be subjected to a large lateral pressure in the outward direction by the scraps, and will be easily deformed or damaged, making it difficult to stably perform precise punching operations.

[0003] To solve the above problem, it is widely known to dispose a scrap pusher made of an elastic plate member such as sponge rubber in the inner gap of the punching blade at a height that protrudes slightly from the tip of the punching blade. According to the above-mentioned conventional technology, when the punching blade cuts into the sheet during the punching operation, the scrap pusher comes into contact with the sheet surface that becomes the scrap and is pressed, compressing and deforming in the blade height direction, and the scrap is temporarily stuck in the inner gap of the punching blade, but when the punching blade separates from the sheet, the scrap pusher is deformed back to its original height, and the scrap that was stuck in the inner gap of the punching blade is pushed back to its original sheet position.

[0004] However, according to the above-mentioned conventional technology, when performing punching to form a very narrow elongated hole or elongated cut of about 2 to 3 mm in a sheet, a punching scrap pusher made of a very thin elastic plate member is used so that it can be placed in the very narrow inner gap of the punching blade, but it is difficult to place such a thin elastic plate member in the narrow inner gap of the punching blade. Even if the thin elastic plate member can be placed, the elastic force to push the punching scrap back to the original sheet position due to its restoring deformation is insufficient and the adjustment of the elastic force is difficult. On the other hand, if a thick elastic plate member is forcibly placed in the narrow inner gap to solve the lack of elastic force, the punching blade will be deformed or broken due to the large lateral pressure during the elastic deformation.

[0005] To alleviate the above-mentioned problems, a punched cushion member (Patent Document 1) has been reported in which elastic plate members made of a relatively hard porous rubber material have elastically deformable drum-shaped protrusions at a required pitch on the top side edge thereof, preventing the member from bulging in the thickness direction even when compressed and deformed.

[0006] However, even with the above technology, it is not possible to adequately handle punching processes such as extremely narrow elongated holes or elongated notches, as mentioned above, and problems remain with respect to the ease of attachment to the inner gap of the punching blade, ensuring elasticity, durability, etc. In any case, if an elastic plate member made of sponge rubber, porous rubber, or the like is used for the punched waste pusher, the elastic plate member, due to its physical properties, is unavoidable from deterioration, wear, reduced durability, etc. due to repeated punching operations, which in turn leads to the punched waste remaining and staying in the inner gap of the punching blade, which applies a large lateral pressure to the punching blade, as mentioned above.

[0007] On the other hand, a sheet punching die (Patent Document 2) has been reported in which an elastic force is applied from the outside of the punching blade to a hard pushing tool arranged in the inner gap of the punching blade. In the sheet punching die, a protruding arm is connected from the outside of the punching blade to a pushing tool slidably provided in the inner gap of the punching blade via an arm insertion part formed of a hole or the like in the punching blade, and an elastic force is applied to the pushing tool by the protruding arm.

[0008] According to the above-mentioned conventional technology, by providing an elastic body that imparts elastic force to the pushing tool on the outside of the punching blade, the elastic body is not limited by the shape or size of the punching blade, and a large elastic body with a large elastic force can be used. Also, according to the above-mentioned conventional technology, as the pushing tool provided in the inner gap of the punching blade, a hard material that has excellent abrasion resistance and durability due to contact with the sheet can be arbitrarily selected instead of a conventional elastic plate member of a synthetic rubber material.

[0009] However, according to the above-mentioned conventional technology, the required elastic force is applied to a hard push-out tool that is slidably mounted in the inner gap of the punching blade by a protruding arm from the outside of the punching blade through an arm insertion part consisting of a hole or the like, which results in problems such as an excessively complex structure with many parts and connecting parts, and an increased size. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2001-347489 A [Patent Document 2] Japanese Patent Application Publication No. 10-217195 Summary of the Invention [Problem to be solved by the invention]

[0011] In view of the above-mentioned problems of the prior art, an object of the present invention is to provide a punched scrap pusher which is small-scale and simple in structure, can be installed in the extremely narrow inner gap of a punching blade even when performing punching processing to form extremely narrow elongated holes or elongated cuts in a sheet, and can push the punched scraps back to their original position on the sheet with the required elastic force.

[0012] Furthermore, another object of the present invention is to provide an excellent sheet punching die which enables highly accurate punching by using the above-mentioned punching chip pusher in punching processes such as extremely narrow slots and slot cuts. [Means for solving the problem]

[0013] The punching dust pusher according to the present invention is a punching dust pusher that is installed in the inner gap of the punching blade when punching a sheet with a sheet punching die having a punching blade implanted in a base plate along a required planned punching shape, and that pushes back the punching dust that has entered the inner gap of the punching blade when the punching blade cuts into the sheet during the punching operation to its original position on the sheet when the punching blade separates from the sheet. The punching dust pusher is movable in the blade height direction within the inner gap of the punching blade, and before the punching blade cuts in, its top protrudes a required length beyond the tip of the punching blade. the rear end of the spring member and is disposed in an inner gap of the punching blade so as to extend from the side hole in the direction of the blade root, and when the spring member elastically deforms, the rear end of the spring member or the end member connected thereto is supported via a pressure receiving surface in the side hole of the punching blade or in the inner gap of the punching blade connected thereto.

[0014] In the above-mentioned configuration, when the punch blade cuts into the sheet during the punching operation, the pressing force of the cut causes the movable member to resiliently press the sheet surface, which becomes the punched waste at the top, toward the blade tip under the compressive deformation of the spring member, and at the same time, the movable member is pushed toward the blade base direction by the reaction force into the inner gap of the punch blade and retreats from its original protruding position, whereby the punched waste enters the inner gap of the punch blade. Note that the movable member may be movable in the blade height direction while sliding in the inner gap of the punch blade, if necessary.

[0015] The spring member is compressed and deformed in a state where the rear end of the spring member or the end member connected thereto is supported by the side hole of the punching blade or the inner gap of the punching blade connected thereto via a pressure receiving surface. For the pressure receiving surface in the side hole of the punching blade, for example, the edge of the side hole located in a position where it is easy to abut and engage with the rear end of the spring member or the vicinity of the connection part between the spring member and the end member can be suitably used as the pressure receiving surface. Furthermore, for the pressure receiving surface in the inner gap of the punching blade, for example, a base plate or its holder that can be exposed near the blade root located in a position where it is easy to abut and engage with the end member arranged in the inner gap can be used as the pressure receiving surface. In addition, in order to abut and engage with the end member arranged in the inner gap of the punching blade, a fixed object having a pressure receiving surface can be interposed in the inner gap, or the punching blade constituting the inner gap can be processed so that it forms a pressure receiving surface. In either case, the rear end of the spring member or the terminal member connected thereto is supported via a pressure-receiving surface in the side hole of the punching blade or in the inner gap of the punching blade connected thereto when the spring member undergoes elastic deformation such as compression deformation, so that the installation structure of the punching scrap pusher is extremely small and simple and does not spread outwardly away from the punching blade and its inner gap.

[0016] When the punching blade separates from the sheet after punching the sheet, the movable member is pushed out from the inner gap of the punching blade toward the blade tip and advances to its original protruding position while elastically pressing the surface of the punched scrap toward the blade tip at its top under the restoring deformation of the spring member, thereby pushing the punched scrap back to its original sheet position from the inner gap of the punching blade. As in the case of the compressive deformation, the restoring deformation of the spring member is performed in a state in which the rear end of the spring member or an end member connected thereto is supported via a pressure receiving surface by the side hole of the punching blade or the inner gap of the punching blade connected thereto.

[0017] The end member is disposed in the inner gap of the punching blade extending from the side hole in the blade root direction, and therefore, in combination with the installation of the movable member in the inner gap of the punching blade, the punching chip pusher is stably installed in the inner gap of the punching blade with the spring member protruding from the side hole of the punching blade. Note that the state in which the spring member protruding in the blade thickness direction is loosely fitted into the side hole of the punching blade also contributes to preventing the punching chip pusher from falling out of the inner gap of the punching blade and stably arranging the punching chip pusher in the inner gap of the punching blade.

[0018] The movable member, the spring member and the end member may be made of different materials, for example, a spring member having a required elasticity may be joined to the movable member and the end member, but in order to be able to be smoothly installed in the very narrow inner gap of the punching blade, it is preferable to integrally form them from a metallic spring material such as cold rolled steel for springs or stainless steel.

[0019] The spring member is not particularly limited in shape, structure, etc., and various shapes and structures that allow elastic deformation in the blade height direction can be used, but protruding members that are curved, for example, in an arc shape, semicircular shape, U-shape, etc., or bent and protruding in a mountain shape, V-shape, etc., are preferably selected because they are easy to effectively elastically deform and simple. The elastic force of the spring member can be appropriately adjusted by, for example, changing the width, thickness, shape, protruding length, etc. of the spring member and selecting the constituent material.

[0020] The spring member may protrude from a side hole of one of the punching blades, but may also protrude alternately on both sides in the blade thickness direction so as to be elastically deformable in the blade height direction, if necessary, and may be loosely fitted into side holes formed on each side of the punching blades on both sides sandwiching an inner gap, so that elastic deformation can occur in the side holes on both sides.

[0021] By installing the scrap extrusion tool of the above configuration in the inner gap of the punching blade of a sheet punching die such as a Thompson die in which the punching blade is implanted into a base plate along the required planned punching shape, it becomes possible to punch out extremely narrow elongated holes, elongated notches, etc. with high precision.

[0022] There is no limitation on the punching mode of the sheet punching die. For example, the sheet may be placed below the edge of the punching blade so as to face the sheet, or conversely, the sheet may be placed above the edge of the punching blade so as to face the sheet, and in these cases, the punching blade may move toward the sheet during punching, or conversely, the sheet may move toward the punching blade. Effect of the Invention

[0023] The scrap pusher of the present invention has a small-scale and simple structure, and can be installed in the extremely narrow inner gap of the punching blade even when performing punching processing to form extremely narrow, elongated holes or elongated cuts in a sheet, and can push the scraps back to their original sheet position with the required elastic force.It also has excellent abrasion resistance due to contact with the sheet, durability during repeated punching, and ease of adjusting the elastic force.

[0024] When the movable member, spring member and end member are integrally formed from a metallic spring material, it is possible to use a metallic spring material that is extremely thin, for example 0.3 mm thick. This allows the material to be smoothly installed in the extremely narrow inner gap of the punching blade, and makes it possible to punch out extremely narrow elongated holes or elongated notches having a width of approximately 1 to 2 mm. Moreover, it is possible to efficiently obtain a scrap extrusion tool that has improved resistance to wear due to contact with the sheet, durability during repeated punching, and ease of adjustment of elastic force.

[0025] Furthermore, if the spring member is curved or bent in the blade thickness direction and projects out, a scrap push-out tool having a spring member with the required elasticity can be easily obtained.

[0026] Furthermore, in a sheet punching die in which the punching blades are implanted into a base plate along the required planned punching shape, a scrap pusher as described above is installed in the inner gap of the punching blade, and this, combined with the excellent action and effect of the scrap pusher, enables highly accurate punching of extremely narrow elongated holes, elongated notches, etc. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a perspective view of a scrap pusher according to an embodiment of the present invention, in which (A) shows the spring member in its natural length with no elastic deformation, and (B) shows the spring member in its compressed and elastically deformed state. [Diagram 2] FIG. 2 is a cross-sectional view of a key part showing over time the operating state of a sheet punching die using the scrap pusher shown in FIG. 1, in which (A) shows the state before the punching operation in which the punching blade is waiting to make a cut, (B) shows the state in which the tip of the punching blade cuts inward from the surface of the sheet, the scrap is punched out of the sheet, and the top of the movable member is pushed into the inner gap of the punching blade, (C) shows the state after punching is completed in which the tip of the punching blade has left the sheet surface and the top of the movable member has been pushed out to the position of the blade tip while pressing against the surface of the scrap, and (D) shows the state in which the tip of the punching blade has moved away from the sheet surface, the top of the movable member has returned to its original protruding position, and the scrap has been pushed back to its original sheet position from the inner gap of the punching blade. [Diagram 3]FIG. 3 is a cross-sectional view of a key part similar to FIG. 2, showing over time the operating state of a sheet punching die using a scrap pusher having a different pressure-receiving surface during elastic deformation from that shown in FIG. 2. FIG. 3(A) shows the state before the punching operation in which the punching blade is waiting to make a cut. FIG. 3(B) shows the state in which the tip of the punching blade cuts inward from the surface of the sheet, the scrap is punched out of the sheet, and the top of the movable member is pushed into the inner gap of the punching blade. FIG. 3(C) shows the state after punching is completed in which the tip of the punching blade has left the sheet surface and the top of the movable member has been pushed out to the position of the tip while pressing against the surface of the scrap. FIG. 3(D) shows the state in which the tip of the punching blade has left the sheet surface, the top of the movable member has returned to its original protruding position, and the scrap has been pushed back to its original sheet position from the inner gap of the punching blade. [Figure 4] FIG. 4 is a cross-sectional view of a main portion of an embodiment of a sheet punching die using a scrap extrusion tool having a spring member with a different shape from those shown in FIGS. 1 to 3, in which (A) shows the spring member in its natural length with no elastic deformation, and (B) shows the spring member in its compressed and elastically deformed state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] The present invention will be described below with reference to examples. As shown in Figures 1(A) and (B), one example of a scrap pusher G according to the present invention comprises a substantially rectangular, thin plate-like movable member 11, a thin plate-like spring member 12 that is curved in a semicircular shape and connected to a base 11b of the movable member 11, and a thin plate-like end member 13 that is connected to a rear end 12b of the spring member 12. In this example, the movable member 11, the spring member 12 and the end member 13 are integrally formed from a metallic spring material.

[0029] In the scrap extrusion tool G, the spring member 12 is normally in a natural length state with no elastic deformation as shown in FIG. 1A, but is compressed and deformed as shown in FIG. 1B by the pressure from the movable member 11. EXAMPLES

[0030] When punching a sheet S, the scrap pusher G is used by being placed in an inner gap 4 of a punching blade 3 in a sheet punching die T in which the punching blade 3 is implanted into a base plate 1 along a required planned punching shape, as shown in Figs. 2(A) to (D).

[0031] In FIG. 2(A), the movable member 11 constituting the punching chip pusher G is arranged in the inner gap 4 of the punching blade 3 so as to be movable in the blade height direction, and before the punching blade 3 cuts, the top part 11a is arranged to protrude from the blade tip 3a of the punching blade 3 by a required length d. The spring member 12 connected to the base part 11b of the movable member 11 and curved and protruded in a substantially semicircular shape in the blade thickness direction is loosely fitted into the side hole 3b drilled in the side of the punching blade 3 so as to be elastically deformable in the blade height direction. In order to enable the spring member 12 to protrude from the side hole 3b of the punching blade 3 and the spring member 12 to elastically deform in the side hole 3b, a cavity 1a is drilled in the base plate 1 around the outer periphery of the side hole 3b. The end member 13 connected to the rear end 12b of the spring member 12 is arranged to extend from the side hole 3b in the blade root direction in the inner gap 4 of the punching blade 3.

[0032] On the other hand, a face plate 2 is disposed opposite the base plate 1 on which the punching blade 3 is attached, and a sheet S to be punched is supplied onto the face plate 2, with the back surface of the base plate 1 being supported by a holder H. Before the punching operation, as shown in FIG. 1A, the cutting edge 3a of the punching blade 3 and the top portion 11a of the movable member 11 protruding from the inner gap 4 of the punching blade 3 are held apart from the sheet S on the face plate 2.

[0033] Next, as shown in FIG. 2(B), when the punching blade 3 moves in the direction of the blade tip toward the face plate 2 and cuts into the sheet S on the face plate 2, a punched scrap Sa is punched out of the sheet S, and the movable member 11, under the compressive deformation of the spring member 12, resiliently presses the surface of the punched scrap Sa in the direction of the blade tip with its apex 11a, and at the same time, the movable member 11 is pushed in the direction of the blade base into the inner gap 4 of the punching blade 3 by the reaction force and retreats, whereby the punched scrap Sa enters the inner gap 4 of the punching blade 3.

[0034] As the movable member 11 retracts, the spring member 12 is compressed and deformed in the blade height direction within the side hole 3b of the punching blade 3 while the vicinity of the connection between the rear end 12b of the spring member 12 and the terminal member 13 is supported in a state in which its pressure-receiving surface P is in contact or engaged with the edge of the side hole 3b of the punching blade 3, more specifically, the edge toward the blade base.

[0035] After punching of the sheet S is completed, as shown in Figures 2(C)-(D), the punching blade 3 moves toward the blade base, and as the punching blade 3 separates from the sheet S and the cutting edge 3a of the punching blade 3 moves away from the surface of the sheet S on the face plate 2, the movable member 11, under the restoring deformation of the spring member 12, resiliently presses the surface of the punched scrap Sa in the cutting edge direction with its apex 11a, and is pushed out from the inner gap 4 of the punching blade 3 in the cutting edge direction and advances to its original protruding position, whereby the punched scrap Sa is pushed back from the inner gap 4 of the punching blade 3 to its original position on the sheet S.

[0036] As the movable member 11 advances forward, the spring member 12, which was compressively deformed in the process shown in Figure 2(B), is deformed back to its original natural length in the blade height direction within the side hole 3b of the punching blade 3, while the vicinity of the connection between the rear end 12b of the spring member 12 and the terminal member 13 is supported in a state of abutment or engagement with the edge of the side hole 3b of the punching blade 3 at its pressure-receiving surface P.

[0037] In the scrap extrusion tool G, when the spring member 12 undergoes elastic deformation such as compressive deformation and restoring deformation, the vicinity of the connection between the rear end 12b of the spring member 12 and the terminal member 13 is supported by its pressure-receiving surface P on the edge of the side hole 3b of the punching blade 3, and the spring member 12 presents a curved and protruding shape in a substantially semicircular shape in the blade thickness direction, but other embodiments can also be implemented. EXAMPLES

[0038] 3(A) to 3(D), an end member 13 connected to a rear end 12b of a spring member 12 is disposed in the inner gap 4 of the punching blade 3 from the side hole 3b toward the blade base with a length sufficient to reach the base plate 1. Note that in this embodiment, unlike the first embodiment, the base plate 1 is disposed in the inner gap 4 of the punching blade 3 near the blade base.

[0039] In this embodiment, during elastic deformation such as the compressive deformation of the spring member 12 during punching of the sheet as shown in FIG. 1(B) and the restoration deformation of the spring member 12 after completion of punching of the sheet as shown in FIG. 1(C), the end member 13 is supported by its pressure receiving surface Q on the base plate 1 which is positioned between the inner gap 4 of the punching blade 3 and has its end portion 13b.

[0040] It should be noted that, when the spring member 12 elastically deforms, what can support the end member 13 in the inner gap 4 of the punching blade 3 is not limited to the pressure receiving surface Q on the base plate 1. Even if the base plate 1 is not disposed in the inner gap 4 as in the case of the first embodiment, it may be, for example, a holder H that abuts against or is fixed to the back surface of the base plate 1, or a movable plate of a press machine, which is exposed inside the inner gap 4, or further, it is also possible for the pressure receiving surface Q to be something that is processed so that the punching blade 3 can abut against and engage with the end member 13 in the inner gap 4. EXAMPLES

[0041] 4(A) and (B), the spring member 12 is bent in a substantially V-shape in the blade thickness direction and protrudes, and is loosely fitted into the side hole 3b of the punching blade 3. Like the curved and protruding spring members 12 in the above-described first and second embodiments, the spring member 12 in this embodiment is also elastically deformed in the blade height direction within the side hole 3b of the punching blade 3, as shown in FIG. 4(B), during sheet punching.

[0042] It goes without saying that the present invention is not limited to the above-described embodiment, and many other wide-ranging aspects can be implemented by various modifications, combinations, etc. that satisfy the requirements of the present invention. [Explanation of symbols]

[0043] H Holder T sheet punching die G Scrap ejector S Seat Sa: Scrap from sheet d Required protrusion length from the tip of the punching blade P: Pressure-receiving surface on the edge of the side hole of the punching blade Q Pressure bearing surface on base plate 1 Base plate 1a Base plate cavity 2 face plates 3 Punching blade 3a Cutting edge of punch blade 3b Side hole of punch blade 4. Inner gap of punch blade 11 Movable parts 11a Top of movable member 11b Base of movable member 12 Spring member 12b Rear end of spring member 13 End member 13b End of end member

Claims

1. A punching chip pusher is provided in an inner gap of the punching blade when punching a sheet using a sheet punching die having a punching blade implanted in a base plate along a required punching shape, and is used to push back punching chips that have entered the inner gap of the punching blade when the punching blade cuts into the sheet during a punching operation to the original position on the sheet when the punching blade separates from the sheet, the punching chip pusher being a movable member that is movable in the blade height direction in the inner gap of the punching blade and has a top that protrudes a required length from the tip of the punching blade before the punching blade cuts in. a spring member connected to the base of the movable member, protruding in the blade thickness direction so as to be elastically deformable in the blade height direction and loosely fitted into a side hole formed in the side of the punching blade, and an end member connected to the rear end of the spring member and extending from the side hole toward the blade base in an inner gap of the punching blade, wherein when the spring member elastically deforms, the rear end of the spring member or the end member connected thereto is supported via a pressure receiving surface in the side hole of the punching blade or in the inner gap of the punching blade connected thereto.

2. 2. The scrap pusher according to claim 1, wherein said movable member, spring member and end member are integrally formed from a metallic spring material.

3. 2. The scrap pusher according to claim 1, wherein the spring member is curved or bent in the blade thickness direction to protrude.

4. A sheet punching die configured by installing the scrap extrusion tool according to any one of claims 1 to 3 in an inner gap of a punching blade in a sheet punching die having a punching blade implanted in a base plate along a required planned punching shape.

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