Polishing method of press die

Abstract

To provide a polishing method of a press die in which a plurality of punches and a plurality of dies can be efficiently polished.SOLUTION: A polishing method of a press die includes a punch conveyance step and a punch polishing step. In the punch conveyance step, a punch plate 32 in which a plurality of punches 33 are fixed is conveyed to a polishing device 50. In the punch polishing step, in a state where the plurality of punches 33 are fixed to the punch plate 32, distal ends of the plurality of punches 33 are polished by the polishing device 50 such that the distal ends are located on the same plane.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a method for polishing a press die. [Background technology]

[0002] Patent Document 1 describes an apparatus for manufacturing a laminated core. The manufacturing apparatus described in Patent Document 1 includes a lower holder, an upper holder located above the lower holder and configured to be able to rise and fall, and a press die provided between the lower holder and the upper holder. The press die includes a die plate fixed to the upper surface of the lower holder, a plurality of dies fixed to the die plate, a punch plate fixed to the lower surface of the upper holder, and a plurality of punches fixed to the punch plate and provided at positions corresponding to the die holes. The die has a die hole penetrating the die in the vertical direction. With a strip-shaped thin steel sheet placed on the upper surface of the die plate, the tip of the punch enters the inside of the die hole as the upper holder descends, thereby punching out an iron core sheet from the strip-shaped thin steel sheet.

[0003] In addition, in such press dies, the opening edge of the die hole and the tip of the punch wear due to friction with the workpiece, which dulls the sharpness of the die and punch. Therefore, the upper surface of the die and the tip of the punch are periodically polished.

[0004] Conventionally, for example, in the press die of a progressive press machine, there is a press die in which a plurality of dies are fixed to one die plate, and in the press die of a progressive press machine, there is a press die in which a plurality of punches are fixed to one punch plate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2023-083475 A Summary of the Invention [Problem to be solved by the invention]

[0006] In a press die, the upper surface of each die is polished with the dies removed from the die plate. Also, the tips of each punch are polished with the punches removed from the punch plate. Therefore, when polishing the dies and punches, it is time-consuming to remove the dies and punches from the die plate and punch plate, respectively, and to attach the dies and punches to the die plate and punch plate, respectively. [Means for solving the problem]

[0007] A polishing method for a press die to solve the above-mentioned problems is applied to a press die including a die plate to which a plurality of dies having die holes are fixed, and a punch plate to which a plurality of punches are fixed that punch out a workpiece in cooperation with the dies and that can move forward and backward relative to the die plate, and the method for polishing the punches includes a transporting step of transporting the punch plate with the plurality of punches fixed thereto to a polishing device, and a polishing step of polishing the tips of the plurality of punches by the polishing device with the plurality of punches fixed to the punch plate so that they are positioned on the same plane.

[0008] According to this method, multiple punches are transported to a grinding device while fixed to a punch plate. Also, while the multiple punches are fixed to the punch plate, the multiple punches are ground by the grinding device so that their tips are positioned on the same plane. This eliminates the need to remove the punches from the punch plate and to attach the punches to the punch plate. This allows multiple punches to be ground efficiently.

[0009] In addition, a polishing method for a press die to solve the above-mentioned problems is applied to a press die including a die plate to which a plurality of dies having die holes are fixed, and a punch plate to which a plurality of punches are fixed that punch out a workpiece in cooperation with the dies and which can move forward and backward relative to the die plate, and the polishing method for polishing the dies includes a transporting step of transporting the die plate with the plurality of dies fixed thereto to a polishing device, and a polishing step of polishing the die plate with the polishing device so that the tip surfaces of the plurality of dies and the die plate are positioned on the same plane with the plurality of dies fixed to the die plate.

[0010] According to this method, multiple dies are transported to a polishing device while being fixed to a die plate. Also, while the multiple dies are fixed to the die plate, they are polished by the polishing device so that the tip faces of the multiple dies and the die plate are positioned on the same plane. This eliminates the need to remove the dies from the die plate and to attach them to the die plate.

[0011] Here, in the case of a method in which the tip surfaces of the multiple dies are polished in a state in which the dies are removed from the die plate, the height of the dies becomes smaller than the height of the die plate by polishing the dies, and therefore a height-adjusting shim is placed on the base end side of the die to prevent a step from occurring between the die plate and the tip surfaces of the dies.

[0012] In this regard, according to the above-mentioned method, the tip faces of the dies and the die plate are polished so as to be located on the same plane, so that the height of the dies is not smaller than the height of the die plate, and therefore the above-mentioned step of arranging the shims is not required.

[0013] Therefore, polishing of a plurality of dies can be performed efficiently. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view of a press machine equipped with a press die according to one embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing a punch transport process. [Diagram 3] FIG. 3 is a cross-sectional view showing a punch polishing process. [Figure 4] FIG. 4 is a cross-sectional view showing a die polishing step. [Diagram 5] FIG. 5 is a cross-sectional view showing a punch polishing step in the modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, one embodiment of a method for polishing a press die will be described with reference to FIGS. First, with reference to FIG. 1, the configuration of a press machine equipped with a press die will be described. The press device 10 is a progressive press device that performs a plurality of punching steps on a thin-plate strip-shaped workpiece W that is intermittently conveyed.

[0016] The press device 10 includes a fixed base 11, a movable base 12 that is movable toward and away from the fixed base 11, and a press die 13 that is provided between the fixed base 11 and the movable base 12. <Fixed stand 11, movable stand 12> As shown in FIG. 1, the fixing base 11 is fixed onto a fixing surface (not shown).

[0017] The movable base 12 is disposed above the fixed base 11 and is configured to be movable up and down by a driving force applied from a driving device (not shown). <Press mold 13> As shown in FIG. 1, the press die 13 includes a die set 14 , a fixed die 15 , and a movable die 16 .

[0018] (Die Set 14) As shown in FIG. 1, the die set 14 includes a fixed die set 20 and a movable die set 30 .

[0019] The fixed die set 20 has a substantially rectangular plate shape, and is fixed to the upper surface of the fixed base 11 . The fixed die set 20 is provided with a plurality of first through holes 20a that vertically penetrate the fixed die set 20. The multiple first through holes 20a are provided at intervals from one another in the conveying direction of the workpiece W (the left-right direction in FIG. 1).

[0020] A plurality of second through holes 20b are provided in the periphery of the fixed die set 20. Note that one second through hole 20b is shown in Fig. 1 . A guide bush 26 is press-fitted into the second through hole 20b.

[0021] The movable die set 30 is fixed to the lower surface of the movable table 12 . The movable die set 30 is provided with a plurality of through holes 30b that pass through the movable die set 30 in the up-down direction at positions that correspond to the plurality of second through holes 20b, respectively.

[0022] A guide post 36 is inserted into the through hole 30b. The guide post 36 is fixed to the movable die set 30 by a bolt (not shown). The lower end of the guide post 36 is inserted into the guide bush 26. The guide post 36 and the guide bush 26 guide the reciprocating movement of the guide post 36 in the axial direction, i.e., the up-down direction, that is, the lifting and lowering of the movable die set 30 relative to the fixed die set 20.

[0023] (Fixed type 15) As shown in FIG. 1, the fixed mold 15 includes a fixed-side backing plate 21, a die plate 22, a die 23, and a fixed-side end block 25.

[0024] The fixed-side backing plate 21 has a generally rectangular shape in a plan view, and is disposed on the upper surface of the fixed-side die set 20 . The fixed-side backing plate 21 is provided with a plurality of through holes 21a that vertically penetrate the fixed-side backing plate 21. The plurality of through holes 21a are provided at positions that respectively correspond to the plurality of first through holes 20a.

[0025] The die plate 22 has a generally rectangular shape in a plan view, and is disposed on the upper surface of the fixed backing plate 21 . The fixed backing plate 21 and the die plate 22 are fixed to the fixed die set 20 by bolts (not shown).

[0026] The die plate 22 has a plurality of through holes 22a that are provided at positions corresponding to the plurality of first through holes 20a and that penetrate the die plate 22 in the up-down direction. A die 23 having a die hole 23a is press-fitted into the through hole 22a. The die hole 23a passes through the die 23 in the vertical direction and communicates with the through hole 21a.

[0027] The fixed end block 25 is fixed to the upper surface of the fixed die set 20 . The upper surface of the fixed end block 25, the upper surface of the die plate 22, and the upper end surface 23b of the die 23, that is, the tip surface, are located on the same plane.

[0028] The upper surface of the fixed end block 25, the upper surface of the die plate 22, and the upper end surface 23b of the die 23 are located above the upper end of the guide bush . (Movable type 16) As shown in FIG. 1, the movable die 16 includes a movable backing plate 31, a punch plate 32, a punch 33, a stripper plate 39, and a movable end block .

[0029] The movable backing plate 31 has a generally rectangular shape in a plan view, and is disposed on the lower surface of the movable die set 30 . The punch plate 32 has a generally rectangular shape in a plan view, and is disposed on the lower surface of the movable backing plate 31 .

[0030] The movable backing plate 31 and the punch plate 32 are fixed to the movable die set 30 by bolts (not shown). The punch plate 32 is provided with a plurality of mounting holes 32a at positions corresponding to the plurality of die holes 23a, respectively. The base ends of a plurality of punches 33 extending in the vertical direction are fitted and attached to the mounting holes 32a. As the movable table 12 descends, the punches 33 entering the die holes 23a cooperate with the die 23 to punch out the workpiece W.

[0031] The stripper plate 39 has a generally rectangular shape in a plan view. The stripper plate 39 is connected to the punch plate 32 via a plurality of biasing members 38 and stripper bolts (not shown). The biasing members 38 are, for example, coil springs.

[0032] The stripper plate 39 is provided with a plurality of through holes 39a that pass through the stripper plate 39 in the up-down direction. The plurality of through holes 39a are provided at positions corresponding to the plurality of die holes 23a, respectively. The plurality of punches 33 are inserted into the plurality of through holes 39a, respectively.

[0033] The movable end block 35 is fixed to the lower surface of the movable die set 30. The movable end block 35 is provided at a position corresponding to the fixed end block 25. The lower end of the movable end block 35 is located above the tip of the punch 33 in a natural state where no compressive force is acting on the biasing member 38.

[0034] Next, with reference to FIG. 3, a regulating jig 40 used in an attachment step to be described later will be described. <Control fixture 40> The regulating jig 40 includes a regulating plate 41 and a spacer 42 .

[0035] The regulating plate 41 has a generally rectangular shape in a plan view, and has a plurality of regulating holes 41a that vertically penetrate the regulating plate 41. The regulating holes 41a are provided corresponding to the plurality of punches 33, respectively, and the plurality of punches 33 are inserted through the regulating holes 41a.

[0036] The spacer 42 has a substantially rectangular parallelepiped shape and is disposed between the punch plate 32 and the regulating plate 41 . Next, a method for polishing the press die 13 will be described with reference to FIGS.

[0037] First, a method for polishing the punch 33 will be described. <How to polish Punch 33> The method for polishing the punch 33 includes a punch transport step, a mounting step, and a punch polishing step.

[0038] (Punch transport process) In the punch transport process, first, while the movable die set 30 is held by a crane of a transport device (not shown), the movable die set 30 is removed from the movable table 12. Then, the movable die set 30 is lifted by the crane, and the guide post 36 is removed from the guide bush 26.

[0039] Next, the guide post 36 is removed from the movable die set 30. Then, the biasing member 38, the stripper bolt, and the stripper plate 39 are removed from the punch plate 32. Next, the movable die set 30 in which the movable backing plate 31, the punch plate 32, the punch 33, and the movable end block 35 are fixed is transported to the polishing device 50.

[0040] As shown in FIG. 2, the movable die set 30 is placed on the mounting table 51 of the polishing device 50 with the tip of the punch 33 facing upward. (Installation process) Next, as shown in FIG. 3, in the attachment process, the regulating jigs 40 are attached to the punches 33.

[0041] In the attachment process, first, a plurality of spacers 42 are placed on the upper surface of the punch plate 32. The spacers 42 are placed on the peripheral edge of the punch plate 32 at intervals. Next, the punches 33 are inserted into the respective restricting holes 41a, and the restricting plate 41 is placed on the upper surface of the spacer 42. By attaching the restricting plate 41 to the punches 33 in this manner, the displacement of the punches 33 in the orthogonal direction perpendicular to the axial direction of the punches 33 is restricted.

[0042] (Punch polishing process) 3, in the punch polishing process, with a plurality of punches 33 fixed to the punch plate 32, the tips of the plurality of punches 33 are polished by a polishing device 50 so as to be positioned on the same plane. The polishing device 50 has a grindstone 52 that is rotated around a rotation axis C.

[0043] The portions of the punches 33 that protrude beyond the restriction holes 41a are ground by a grinding device 50 so as to be positioned on the same plane. Next, a method for polishing the die 23 will be described.

[0044] The method for polishing the die 23 includes a die transport step and a die polishing step. <Die transport process> 4, in the die transport process, first, the fixed-side die set 20 is removed from the fixed table 11. Then, the fixed-side die set 20 with the fixed-side backing plate 21, die plate 22, die 23, fixed-side end block 25, and guide bush 26 fixed thereto is lifted by a crane of a transport device (not shown) and transported to a polishing device 50.

[0045] <Die polishing process> Next, as shown by the dotted line in Figure 4, in the die polishing process, with multiple dies 23 fixed to the die plate 22, the upper end surfaces 23b of the multiple dies 23 and the upper surface of the die plate 22 are polished by a polishing device 50 so that they are positioned on the same plane.

[0046] When the die 23 and punch 33 after grinding are reattached to the press device 10, the movable range of the movable table 12 is reset so that the bottom dead center of the movable table 12 is lower than the bottom dead center of the movable table 12 before grinding, as the height of the die 23 and the height of the punch 33 after grinding decrease.

[0047] Next, the operation of this embodiment will be described. 2 and 3, the multiple punches 33 are transported to the grinding device 50 while being fixed to the punch plate 32. Furthermore, while the multiple punches 33 are fixed to the punch plate 32, they are ground by the grinding device 50 so that the tips of the multiple punches 33 are positioned on the same plane. This eliminates the need to remove the punches 33 from the punch plate 32 and to attach the punches 33 to the punch plate 32 (above, action 1).

[0048] 4, the multiple dies 23 are transported to the polishing device 50 in a state where they are fixed to the die plate 22. In addition, in a state where the multiple dies 23 are fixed to the die plate 22, they are polished by the polishing device 50 so that the upper end surfaces 23b of the multiple dies 23 and the die plate 22 are positioned on the same plane. Therefore, the effort of removing the dies 23 from the die plate 22 and the effort of attaching the dies 23 to the die plate 22 can be omitted.

[0049] Here, in the case of a method in which the upper end surface 23b of each of the dies 23 is polished in a state in which the multiple dies 23 are removed from the die plate 22, the height of the die 23 becomes smaller than the height of the die plate 22 by polishing the die 23. Therefore, a shim for adjusting the height is disposed on the base end side of the die 23 so that a step does not occur between the die plate 22 and the upper end surface 23b of the die 23.

[0050] In this regard, according to the above-mentioned method, the upper end faces 23b of the multiple dies 23 and the die plate 22 are polished so as to be located on the same plane, so that the height of the dies 23 is not smaller than the height of the die plate 22. Therefore, the above-mentioned step of arranging the shim is not required (above, effect 2).

[0051] Next, the effects of this embodiment will be described. (1) The polishing method for the press die 13 includes a punch transport step and a punch polishing step. In the punch transport step, the punch plate 32 to which the multiple punches 33 are fixed is transported to the polishing device 50. In the punch polishing step, with the multiple punches 33 fixed to the punch plate 32, the tips of the multiple punches 33 are polished by the polishing device 50 so as to be positioned on the same plane.

[0052] According to this method, since the above-mentioned effect 1 is achieved, the polishing of the plurality of punches 33 can be carried out efficiently. (2) The polishing method for the press die 13 includes an attachment step of attaching, to the plurality of punches 33, regulating plates 41 that regulate displacement of the punches 33 in a direction perpendicular to the axial direction of the plurality of punches 33, prior to the punch polishing step. In the punch polishing step, the portions of the plurality of punches 33 that protrude beyond the regulating holes 41a are polished by a polishing device 50 so as to be positioned on the same plane.

[0053] According to this method, the displacement of the punch 33 in the orthogonal direction is restricted by the restricting plate 41. Furthermore, by using the restricting plate 41, the portion of the punch 33 protruding from the restricting hole 41a of the restricting plate 41 can be polished and removed, so that the tips of the multiple punches 33 can be easily polished to be positioned on the same plane. This makes it possible to improve the polishing accuracy while polishing multiple punches 33 at once.

[0054] (3) In the mounting step, the spacer 42 is disposed between the punch plate 32 and the regulating plate 41. Repeated grinding of the punch 33 gradually reduces the height of the punch 33. For this reason, in the grinding process, it is necessary to prepare a plurality of regulating plates 41 having different heights according to the height of the punch 33.

[0055] In this regard, according to the above method, a plurality of spacers 42 having different heights are prepared, and a spacer 42 having a desired height is selected and placed between the punch plate 32 and the regulating plate 41, thereby making it possible to standardize the regulating plate 41. Alternatively, the spacer 42 having a desired height obtained by grinding the spacer 42 can be placed between the punch plate 32 and the regulating plate 41, thereby making it possible to standardize the regulating plate 41. In addition, the thickness of the regulating plate 41 can be reduced. Therefore, the equipment can be made smaller and simpler.

[0056] (4) The polishing method for the press die 13 includes a die transport step and a die polishing step. In the die transport step, the die plate 22 to which the multiple dies 23 are fixed is transported to a polishing device 50. In the die polishing step, with the multiple dies 23 fixed to the die plate 22, the upper end faces 23b of the multiple dies 23 and the die plate 22 are polished by the polishing device 50 so that they are positioned on the same plane.

[0057] According to this method, since the above-mentioned effect 2 is achieved, the polishing of the multiple dies 23 can be carried out efficiently. <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0058] In the present embodiment, the spacer 42 is disposed between the punch plate 32 and the regulating plate 41 in the attachment process, but the present invention is not limited to this. As shown in Fig. 5, a spacer 142 may be disposed between the upper surface of the movable die set 30 and the regulating plate 41.

[0059] Furthermore, spacers (not shown) may be disposed between the upper surface of the punch plate 32 and between the upper surface of the movable die set 30 and the regulating plate 41, respectively. Even in these cases, by selecting a spacer of a desired height and placing it between the movable die set 30 and the regulating plate 41, it is possible to obtain the same effect as the effect (3) of the above embodiment.

[0060] The spacer 42 may be omitted. In this case, a plurality of regulating plates 41 having different heights may be prepared, and the regulating plate 41 having a height corresponding to the height of the punch 33 may be used.

[0061] When grinding the punch 33, if there is no displacement of the punch 33 in the orthogonal direction by the grinding device 50, or if the displacement of the punch 33 in the orthogonal direction by the grinding device 50 is negligibly small, the regulating plate 41 can be omitted.

[0062] In the present embodiment, in the punch transport step, the punch plate 32 to which the multiple punches 33 are fixed is transported to the polishing device 50 by transporting the movable die set 30, but this is not limited to the above. The punch plate 32 to which the multiple punches 33 are fixed may be removed from the movable die set 30 and then transported to the polishing device 50.

[0063] Similarly, for the dies 23, in the die transport step, the fixed die set 20 is transported to transport the die plate 22 to which the multiple dies 23 are fixed to the polishing device 50, but this is not limiting. The die plate 22 to which the multiple dies 23 are fixed may be removed from the fixed die set 20 and transported to the polishing device 50. [Explanation of symbols]

[0064] 10...Pressing device 11...Fixed stand 12…Movable base 13... Press mold 14…Die set 15…Fixed type 16…Movable type 20…Fixed side die set 20a...1st through hole 20b…Second through hole 21…Fixed side backing plate 21a...Through hole 22…Die plate 22a...Through hole 23…Die 23a…Die hole 23b…Top end surface 25…Fixed end block 26...Guide bush 30…Movable die set 30b...Through hole 31…Movable backing plate 32...Punch plate 32a…Mounting hole 33...Punch 35…Movable end block 36…Guidepost 38... Urging member 39…Stripper plate 39a...Through hole 40...Regulating jig 41...Regulation plate 41a…Regulation hole 42,142…Spacer 50...Polishing equipment 51...Placement table 52...Whetstone

Claims

1. A method for grinding a press die, comprising: a die plate to which a plurality of dies having die holes are fixed; and a punch plate to which a plurality of punches are fixed and which are movable forward and backward relative to the die plate and which punch out a workpiece in cooperation with the dies, the method comprising: a conveying step of conveying the punch plate to which the plurality of punches are fixed, to a polishing device; a polishing process in which, with the punches fixed to the punch plate, tips of the punches are polished by the polishing device so as to be positioned on the same plane. How to polish press dies.

2. a mounting step of mounting a regulating plate to the plurality of punches, the regulating plate restricting displacement of the punches in a direction perpendicular to an axial direction of the plurality of punches, before the grinding step; the regulating plate has regulating holes through which the plurality of punches are respectively inserted, In the polishing step, the portions of the punches protruding beyond the restriction holes are polished by the polishing device so as to be positioned on the same plane. The method for polishing a press die according to claim 1.

3. the press die includes a fixed die set to which the die plate is fixed, and a movable die set located on a base end side of the punch and to which the punch plate is fixed, In the attaching step, a spacer is disposed between the regulating plate and at least one of the punch plate and the movable die set. The method for polishing a press die according to claim 2.

4. A method for polishing a press die, comprising: a die plate to which a plurality of dies having die holes are fixed; and a punch plate to which a plurality of punches are fixed that punch out a workpiece in cooperation with the dies and that can advance and retreat relative to the die plate, the method being applied to a press die and comprising: a conveying step of conveying the die plate to which the plurality of dies are fixed, to a polishing device; and a polishing step of polishing the front end surfaces of the dies and the die plate by the polishing device while the dies are fixed to the die plate so that the front end surfaces of the dies and the die plate are positioned on the same plane. How to polish press dies.

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