How to adjust the height of the punching blade for a sheet-like workpiece punching die

Abstract

To provide a method for adjusting a punching blade height which enables the simple and short-time adjustment of a punching blade height according to the thickness or material of a sheet-like work to a rule blade and makes a punching work efficient.SOLUTION: A reference or throw-away blade is mounted on a die plate at a low height corresponding to the plastic deformation amount of a fragile site as compared with the mount height of a punching blade, and a rule blade is mounted low as compared with the mount height of the reference blade by a factor of a rule groove depth formed in a product sheet. Before the punching work of the product sheet, the fragile part is plastically deformed to adjust the height of the punching blade by moving the die plate mounted on a machine platen in a direction of approaching a surface plate to make the punching blade perform pressure-welding to a position where the reference blade contacts the surface plate with respect to the surface plate, and simultaneously the height adjustment of the rule blade with respect to the punching blade is executed.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a method for adjusting the height of a punching blade of a sheet-like workpiece punching die attached to a punching device for punching product sheets from sheet-like workpieces such as paper, cardboard, and plastic sheets. [Background technology]

[0002] In the case of a punching blade provided on a punching die attached to the base plate (upper platen) of a sheet-like workpiece punching device, in order to punch out a product sheet in the product unfolded shape from a sheet-like workpiece without leaving any uncut areas and without damaging the blade tip, it is necessary to adjust the height so that the height from the template is constant and so that the entire tip of the punching blade is evenly pressed against the face plate (lower platen) on which the seed-like workpiece is set.

[0003] In Patent Document 1, the applicant proposed a punching blade whose base end (the side opposite the cutting edge) is easily deformed and whose height can be adjusted in accordance with the deformation, in order to eliminate unevenness in the overall height of the punching blade protruding from a flat wooden mold, so as to cut the product sheet from the sheet-like workpiece without leaving any uncut product sheet and without damaging the cutting edge.

[0004] However, with the punching blade of Patent Document 1, although the height of the entire punching blade can be easily adjusted, it is necessary to adjust the height in relation to the scoring blade.

[0005] That is, in the case of the scoring grooves that become the creases when the product sheet is folded and assembled into a product, the groove depth, and therefore the height of the scoring blade relative to the punching blade, must be adjusted according to the material and thickness of the sheet. For example, to form shallow scoring grooves, the distance between the cutting edge of the punching blade and the tip of the scoring blade must be adjusted to be wide, and conversely, to form deep scoring grooves, the distance between the cutting edge of the punching blade and the tip of the scoring blade must be adjusted to be narrow.

[0006] Furthermore, if the score grooves are too deep for the sheet-like workpiece, spine cracks may occur, deteriorating the product quality, whereas if they are too shallow, it becomes difficult to effectively fold the product sheet.

[0007] To solve this problem, in the past, before starting the punching operation, trial punches were repeatedly made to adjust the height of the punching blade relative to the scoring blade to the optimum distance depending on the thickness and material of the sheet workpiece. However, this adjustment work took time and effort, making the punching operation less efficient. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 7064729 Summary of the Invention [Problem to be solved by the invention]

[0009] The problem to be solved is that in order to adjust the height of the punching blade relative to the scoring blade to a specified distance according to the thickness and material of the sheet-like workpiece, trial punches must be repeated before starting the punching operation to adjust the height of the scoring blade relative to the punching blade, and this adjustment work is time-consuming and labor-intensive, making the punching operation less efficient. [Means for solving the problem]

[0010] The most important feature of the invention according to claim 1 is that a reference blade is attached to a template at a lower height than the mounting height of the punching blade depending on the amount of plastic deformation of the weak portion, and a scoring blade is attached lower than the mounting height of the reference blade by the depth of the scoring groove to be formed in the product sheet, and when the template attached to the base plate is moved toward the face plate of the sheet-like workpiece punching device to perform a test punch prior to the punching operation of the product sheet, the punching blade is pressed against the face plate to a position where the reference blade abuts the face plate, thereby plastically deforming the weak portion and adjusting the height of the punching blade and at the same time adjusting the height of the scoring blade relative to the punching blade.

[0011] The most important feature of the invention according to claim 2 of the present invention is that a stamper blade for dividing a scrap sheet, from which a product sheet has been punched out of a sheet-like workpiece, into at least two pieces is attached to the template at a lower height than the mounting height of the punching blade depending on the amount of plastic deformation of the weak portion, and a crease blade for forming a crease groove in the product sheet is attached at a lower mounting height than the mounting height of the reference blade by the depth of the crease groove to be formed in the product sheet, and when the template attached to the base plate is moved toward the face plate of the sheet-like workpiece punching device to perform a test punch prior to the punching operation of the product sheet, the punching blade is pressed against the face plate until the stamper blade abuts the face plate, thereby plastically deforming the weak portion and adjusting the height of the punching blade and at the same time adjusting the height of the crease blade relative to the punching blade. Effect of the Invention

[0012] The present invention can easily and quickly adjust the height of the scoring blade relative to the punching blade according to the thickness and material of the sheet work, thereby making punching operations more efficient. [Brief description of the drawings]

[0013] [Figure 1] 1 is a bottom view of a sheet-like workpiece punching die attached to a sheet-like workpiece punching device, as viewed from below. FIG. [Diagram 2] FIG. [Diagram 3]FIG. 4 is an explanatory diagram showing the interrelationship of heights of a punching blade, a reference blade, and a scoring blade. [Figure 4] FIG. 11 is an explanatory diagram showing a state in which the punching blade is in partial contact with the face plate. [Diagram 5] 10 is an explanatory diagram showing a state in which the height of the punching blade is adjusted by plastic deformation of the weak portion. FIG. [Figure 6] FIG. 11 is an explanatory diagram showing a state in which the height of the scoring blade is adjusted relative to the punching blade. [Figure 7] FIG. 4 is an explanatory diagram showing the punching state of a sheet workpiece and the formation of score grooves. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] In the best embodiment, a reference blade or stamping blade is attached to the template at a lower height corresponding to the amount of plastic deformation of the weak portion relative to the mounting height of the punching blade, and the scoring blade is attached lower than the mounting height of the reference blade by the depth of the scoring groove to be formed in the product sheet, and when the template attached to the base plate is moved toward the face plate of the sheet-like workpiece punching device to perform a test punch prior to the punching operation of the product sheet, the punching blade is pressed against the face plate to a position where the reference blade abuts the face plate, plastically deforming the weak portion to adjust the height of the punching blade and simultaneously adjusting the height of the scoring blade relative to the punching blade. EXAMPLES

[0015] A method for adjusting the height of a cutting blade in a punching die for a sheet-like workpiece according to the present invention will be described below with reference to the drawings. First, an overview of the punching die attached to a base plate 1b of a sheet-like workpiece punching device (not shown) as shown in Figures 1 to 3 will be given. The punching die 1 is fitted with a flat wooden die 1a serving as a template made of plywood or the like, a punching blade 7 which is formed by folding and bending to match the developed shape of a product sheet (not shown) to be punched out from a sheet-like workpiece 3 such as paper, cardboard or a plastic sheet, a cutting blade 9 which cuts and fragments scrap sheets (punch waste sheets, skeletons, not shown) which are left over from the sheet-like workpiece 3 after the product sheet has been punched out, a reference blade 11 for adjusting the height of the punching blade 7, and a scoring blade 13 which forms grooves corresponding to the folds in the product sheet 5.

[0016] The punching blade 7 (shown by a solid line in FIG. 1) is formed from a strip-shaped steel plate having a length (height) L1 (width perpendicular to the longitudinal direction) of 24 mm and a thickness of 0.7-1.5 mm, with a blade portion 7a at the tip that has been hardened by quenching, and a weak portion 7b at the base end. The weak portion 7b is tapered so that the base end of the punching blade 7 gradually narrows at a predetermined angle toward the base end, and is formed so that, for example, when the blade thickness is 0.7 mm, the base end surface thickness is 0-0.6 mm, when the blade thickness is 0.9 mm, the base end surface thickness is 0-0.8 mm, and when the blade thickness is 1.4 mm, the base end surface thickness is 0-1.3 mm.

[0017] In addition, the fragile portion 7b is formed with a number of notches (slits) 7c at appropriate intervals in the longitudinal direction. The notches 7c are formed, for example, to have a depth from the base end face of 0.05-3 mm, a width in the longitudinal direction of 0.1-5 mm, and an arrangement number of 4-130 per inch in the longitudinal direction. In addition to the above-mentioned configuration, the weakened portion 7b may be formed by tempering the base end portion of the punching blade 7 or by forming it into a tapered shape to reduce the hardness so as to be deformable. For detailed explanations of the punching blade 7 and modified embodiments, the description in Patent Document 1 (Japanese Patent No. 7064729) is cited, and the cited explanations are described below.

[0018] As shown in FIG. 3, the punching blade 5 is made of a strip-shaped steel plate having a height of, for example, 23.6 mm and a thickness of 0.7 mm, and has a blade portion 5a at its tip end with a predetermined blade height and blade angle (for example, 40° to 50°), and a tapered portion 5b at its base end with a predetermined taper angle (for example, 10° to 20°) and length, the thickness of which gradually decreases to a base end thickness of 0 to 0.6 mm. The taper angle and base end thickness of the tapered portion 5b are selected arbitrarily depending on the plastic deformation characteristics of the punching blade 5. Although the above base end surface thickness is shown as a value when the blade thickness of the punching blade 5 is 0.7 mm, when the blade thickness is 0.9 mm, the base end surface thickness may be selected in the range of 0 to 0.8 mm, and when the blade thickness is 1.4 mm, the base end surface thickness may be selected in the range of 0 to 1.3 mm. In addition, the tapered portion 5b may have a linear shape in which the thickness gradually decreases toward the base end as shown in the figure, or may have a shape in which the thickness gradually decreases in a curved manner toward the base end as shown in Figure 4, or a shape in which the thickness gradually decreases in a stepped manner toward the base end as shown in Figure 5. The height and thickness of the punching blade 5 are not limited to those described above, but are selected arbitrarily depending on the thickness of the sheet-like workpiece to be punched and the number of stacked sheet-like workpieces (the number of sheet-like workpieces to be punched in one punching operation). The tip portion including the blade portion 5a of the punching blade 5 is hardened by high-frequency heating or the like to increase its hardness. On the other hand, the base end portion including the tapered portion 5b is not hardened and has lower hardness than the tip portion, resulting in metal properties that make it prone to plastic deformation. The tapered portion 5b has a number of notches 15 formed at predetermined intervals in the longitudinal direction. Each notch 15 has a depth (depth from the base end) of 0.05 to 3 mm, a longitudinal width of 0.1 to 5 mm, and is formed at intervals of 4 to 130 notches per inch in the longitudinal direction. The taper angle, length and base end thickness of the tapered portion 5b, as well as the depth, longitudinal width and number per unit of the notches 15 formed in the tapered portion 5b, are appropriately set within a range in which the force that allows the tapered portion 5b to plastically deform is higher than the shear force applied to the sheet-like workpiece and lower than the force that can damage the cutting edge.

[0019] The above-mentioned steel blade 9 (shown by a short dashed line in FIG. 1) has, for example, a blade portion at its tip, and is formed from a strip-shaped steel plate having a thickness of 0.7-1.5 mm and a short length (height) L2 corresponding to the deformation length of the weak portion 7b when the cutting edges of all the punching blades 7 are pressed against the face plate 1c relative to the above-mentioned punching blades 7, and is attached at a location located outside the punching holes in the product sheet in the sheet-like workpiece 3, where it will divide the scrap sheet 5a into several pieces.

[0020] In addition, the reference blade 11 (shown by a long dashed line in Figure 1) has a blade portion at the tip if necessary, and is formed from a strip of steel plate with a length (height) L2 matching that of the above-mentioned steel blade 9 and a thickness of 0.7-1.5 mm.When punching out two product sheets from one sheet-like workpiece 3, for example, the reference blade 11 is attached so as to extend in the longitudinal direction and in the direction perpendicular to the longitudinal direction at equal intervals between the product sheets in the sheet-like workpiece 3, preferably at multiple points in the longitudinal center of the sheet-like workpiece 3.

[0021] Depending on the location of the reference blade 11, the step blade 9 may be used as the reference blade 11. The step blade 9, reference blade 11 and scoring blade 13 are hardened by quenching, so that their base ends are not particularly weakened. The height difference between the punching blade 7 and the step blade 9 and reference blade 11 is set to δ1.

[0022] The scoring blade 13 (shown by a short dotted line in Figure 1) has, for example, a flat, curved or hemispherical tip surface, and is formed from a strip of steel plate with a thickness of 0.7-1.5 mm and a shorter length (height) L3 than the steel blade 9 and reference blade 11, which is the difference δ2 between the depth D of the scoring groove 3a formed in the product sheet and the plate thickness, and is attached at a location opposite the scoring groove 3a.

[0023] The depth D of the score groove 3a is set arbitrarily within a range in which the spine does not crack depending on the material and thickness of the sheet-like workpiece 3, the bending angle, etc., and is generally within a range of less than 1 / 2 the thickness of the sheet-like workpiece 3.

[0024] That is, the lengths (heights) of the punching blade 7, the step blade 9, the reference blade 11 and the scoring blade 13 are attached to the flat wooden die 1a in the height relationship shown in FIG.

[0025] Next, a method for adjusting the height of the punching blade 7 using the punching die 1 constructed as above will be described.

[0026] Prior to punching a product sheet from a sheet-like workpiece using the punching die 1, a platen 1b to which the punching die 1 is attached is moved toward the face plate 1c of the punching device with or without the sheet-like workpiece 3 placed on the face plate 1c, and a test punching operation is performed to remove unevenness by pressing the cutting edge of the punching blade 7 against the upper surface of the face plate 1c.

[0027] When the punching die 1 is attached to the base plate 1a, the weakened portion 7b of the punching blade 7 is attached so that the base end surface thereof abuts against the base plate 1b in an undeformed state.

[0028] The above test punching work is performed to prevent punching defects or damage to the blade tip due to the pressing force of the punching blade 7 against the face plate 1b becoming uneven, which may occur when the height of the folded parts of the punching blade 7, which has been folded to correspond to the outer shape of the product sheet, becomes lower than the non-folded parts, or when the entire punching blade 7 cannot be pressed uniformly against the face plate 1c due to slight variations in the parallelism and flatness of the base plate 1b and face plate 1c, or when the punching blade 7 is attached to the flat wooden mold 1a (see Figure 4).

[0029] During this test punching operation, if there is an unevenness in height where some of the blades 7a are pressed excessively against the top surface of the face plate 1c, the weakened portions 7b of the punching blade 7 at the locations where the blades are pressed excessively against the face plate 1c will be plastically deformed by the force corresponding to the excessive pressing. At that time, since numerous notches 15 are formed in the weakened portions 7b, further weakening them, the weakened portions 7b will easily plastically deform before the blades 7a are damaged, lowering the height of the punching blade 7. (See FIG. 5)

[0030] Then, the base plate 1b is moved relative to the face plate 1c until the tip of the reference blade 11 or the stamping blade 9 is pressed against the face plate 1c while plastically deforming the weak portion 7b of the punching blade 7, thereby adjusting the overall height of the punching blade 7 to the height of the reference blade 11 or the stamping blade 9 so that the height of the entire punching blade 7 is uniform.

[0031] Furthermore, when the overall height of the punching blade 7 is adjusted to be the height of the reference blade 11 or the step blade 9, the difference in height between the reference blade 11 or the step blade 9 and the crease blade 13 is set to the depth D of the crease groove 3a to be formed by the crease blade 13, so the difference in height between the punching blade 7 and the crease blade 13 is set to be a constant difference δ2 (see FIG. 6).

[0032] When punching a product sheet from the sheet-like workpiece 3 placed on the face plate 1c using the punching blade 7, stamping blade 9 and ruling blade 13 which have been test cut and adjusted in height as described above, the product sheet can be punched out from the sheet-like workpiece 3 without any uncut portions by the punching blade 7 which has been adjusted in height so that the entire product sheet is evenly pressed against the face plate 1c as the base plate 1b moves relative to the face plate 1c.

[0033] In this case, the distance between the cutting edge of the punching blade 7 and the tip of the scoring blade 13 becomes the difference δ2 in the scoring groove 3a, so the scoring groove 3a formed during the punching operation can always be formed to a constant depth D (sheet work thickness - δ2) that is preset according to the thickness and material of the sheet work 3, preventing spine cracks and the like and forming high-quality scoring groove 3a (see Figure 7).

[0034] In addition, during the above punching operation, the scrap sheet from which the product sheet 5 has been punched out is cut into multiple pieces and divided into small pieces by the stamper blade 9, the cutting edge of which is pressed against the face plate 1c, making it easy to remove the scrap sheet from the face plate 1c after the punching operation. [Explanation of symbols]

[0035] 1 Punching die 1a Flat wooden mold as a template 1b Surface plate 1c face plate 3 Sheet work 3a Crease groove 7 Punching blade 7a Blade part 7b Weak area 7c notch 9. Steady blade 11 Reference blade 13 Crease blade δ Deformation length L1, L2, L3 Length δ1, δ2 difference D Depth

Claims

1. In a punching die for punching a product sheet from a sheet-like workpiece, a die plate is attached to the base plate of a sheet-like workpiece punching device, the die plate having a punching blade for a strip steel plate, the punching blade having a blade portion at the tip end and a weak portion at the base end that can be plastically deformed by pressing against the base plate, A reference blade is attached to the template at a lower height than the mounting height of the punching blade in accordance with the length of plastic deformation of the weakened portion, and a crease blade is attached at a lower height than the mounting height of the reference blade by a depth of the crease groove to be formed in the product sheet, This punching blade height adjustment method, when a template attached to a fixed plate is moved toward the face plate of a sheet-like workpiece punching device to perform a test punch prior to the punching operation of a product sheet, presses the punching blade against the face plate until a reference blade abuts against the face plate, plastically deforming the weak part to adjust the height of the punching blade and simultaneously adjusts the height of the scoring blade relative to the punching blade.

2. In a punching die for punching a product sheet from a sheet-like workpiece, a die plate is attached to the base plate of a sheet-like workpiece punching device, the die plate having a punching blade for a strip steel plate, the punching blade having a blade portion at the tip end and a weak portion at the base end that can be plastically deformed by pressing against the base plate, A stamping blade for dividing a scrap sheet into at least two pieces, which is a product sheet punched out from a sheet-like workpiece, is attached to the template at a lower height than the mounting height of the punching blade in accordance with the amount of plastic deformation of the weak portion, and a crease blade for forming a crease groove in the product sheet is attached at a lower mounting height than the mounting height of the stamping blade by the depth of the crease groove to be formed in the product sheet, This punching blade height adjustment method, when a template attached to a fixed plate is moved toward the face plate of a sheet-like workpiece punching device to perform a test punch prior to the punching operation of a product sheet, presses the punching blade against the face plate until the stamping blade abuts against the face plate, plastically deforming the weak part to adjust the height of the punching blade and simultaneously adjusts the height of the scoring blade relative to the punching blade.

3. In any one of claims 1 and 2, The method for adjusting the height of a punching blade of a punching die for a sheet-like workpiece, wherein the weakened portion has been subjected to a tempering treatment to reduce hardness.

4. In any one of claims 1 and 2, A method for adjusting the height of a punching blade of a die for punching a sheet-like workpiece, wherein the weakened portion is a linearly inclined surface whose thickness gradually decreases toward the base end.

5. In any one of claims 1 and 2, The method for adjusting the height of a punching blade of a die for punching a sheet-like workpiece, wherein the weakened portion is a curved inclined surface whose thickness gradually decreases toward the base end.

6. In any one of claims 1 and 2, A method for adjusting the height of a punching blade of a die for punching a sheet-like workpiece, wherein the weakened portion is stepped so that its thickness gradually decreases toward the base end.

7. In any one of claims 3 to 6, A method for adjusting the height of a punching blade of a die for punching sheet-like workpieces, wherein notches of a predetermined depth are formed from the base end of the weakened portion at predetermined intervals in the longitudinal direction of the punching blade.

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