Method for grasping bottom dead center of mold device, and mold device

Abstract

To provide a method for grasping a bottom dead center of a mold device that can grasp a bottom dead center of a movable mold with higher accuracy, and the mold device.SOLUTION: A mold device comprises: a fixed mold; a movable mold; and a pair of stroke end blocks 16 which are respectively provided on an opposite face to the movable mold in the fixed mold and an opposite face to the fixed mold in the movable mold, and face each other. A recessed groove 24 is formed in one apical surface 23 provided on the fixed mold of the pair of stroke end blocks. A method for grasping the bottom dead center of the mold device comprises: an arrangement process in which a deformed member 25 having an outer diameter A larger than a depth B of the recessed groove 24 is arranged so that a part thereof projects from the recessed groove 24; a compression process in which the movable mold is moved to a bottom dead center, and the deformed member 25 is compressed and is plastically deformed by the pair of stroke end blocks 16; a measurement process in which a thickness in a compression direction of the deformed member 25 which has been plastically deformed is measured; and a calculation process in which the bottom dead center of the movable mold is calculated on the basis of the measured thickness of the deformed member 25.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for determining the bottom dead center of a mold apparatus and a mold apparatus. [Background technology]

[0002] Generally, the bottom dead center of the slide of a press machine can shift due to factors such as heat accumulation during operation and changes in the outside air temperature. For this reason, a method for determining the bottom dead center position of a press machine is known, for example, as shown in Patent Document 1. This method for determining the bottom dead center position of a press machine determines whether the bottom dead center of the slide is appropriate as follows.

[0003] At least one of a pair of dies attached to the bolster and slide of the press machine has an engraved portion with a plurality of protrusions of different heights. When the slide is moved to the bottom dead center, the pressing action of the protrusions of the engraved portion forms several recesses in the non-product area of ​​the workpiece. Whether the bottom dead center of the slide is appropriate is determined based on the number of recesses formed in the non-product area. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-142852 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-described method for determining the bottom dead center position of a press machine, the difference in the smallest height dimension between multiple protrusions results in a measurement error in the bottom dead center of the slide, which leaves room for improvement in determining the bottom dead center of the slide with higher accuracy. [Means for solving the problem]

[0006] The means for solving the above problems and their effects will be described below. A method for determining the bottom dead center of a mold apparatus that solves the above-mentioned problem is a method for determining the bottom dead center of a mold apparatus that includes a fixed mold, a movable mold arranged opposite the fixed mold so as to be movable toward and away from the fixed mold, and at least a pair of opposing stroke end blocks provided on the fixed mold's opposing surface facing the movable mold and the movable mold's opposing surface facing the fixed mold, respectively. The method comprises the following steps: a positioning step in which a recess is formed on the tip surface of one of the pair of stroke end blocks that is provided on the fixed mold, and a deformable member that plastically deforms when compressed and has a maximum width greater than the depth of the recess is arranged in the recess so that a portion of the deformable member protrudes from the recess; a compression step in which the movable mold is moved to the bottom dead center and the deformable member is sandwiched and compressed between the pair of stroke end blocks to plastically deform it; a measurement step in which the thickness of the deformable member in the compression direction that has been plastically deformed in the compression step; and a calculation step in which the bottom dead center of the movable mold is calculated based on the thickness of the deformable member measured in the measurement step.

[0007] According to the above method, the bottom dead center of the movable mold is calculated based on the actual measured value of the thickness in the compression direction of the deformed member plastically deformed in the compression process, so that the bottom dead center of the movable mold can be determined with greater accuracy.

[0008] The mold device that solves the above problem is a mold device that includes a fixed mold, a movable mold that is arranged opposite the fixed mold and can move toward and away from the fixed mold, and at least a pair of opposing stroke end blocks that are provided on the opposing surface of the fixed mold to the movable mold and the opposing surface of the movable mold to the fixed mold, respectively, and the tip surface of the stroke end block provided on the fixed mold has a recess formed in it in which a deformable member that is plastically deformed by being sandwiched and compressed between the pair of stroke end blocks is placed.

[0009] According to the above configuration, when the movable mold is moved to the bottom dead center with the deformable member placed in the recess and the deformable member is sandwiched and compressed between the pair of stroke end blocks, the deformable member undergoes plastic deformation. By measuring the thickness of the plastically deformed deformable member in the compression direction, the bottom dead center of the movable mold can be calculated based on the actual measured thickness. This makes it possible to determine the bottom dead center of the movable mold with greater accuracy. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a schematic cross-sectional view showing a main part of a mold device when a movable mold of one embodiment is at the top dead center. [Figure 2] 2 is a schematic cross-sectional view showing a state in which the movable die in FIG. 1 is at the bottom dead center. FIG. [Figure 3] 10 is a schematic plan view showing the fixed-side block when a deformable member is placed in a recessed groove. FIG. [Figure 4] 4 is an enlarged schematic cross-sectional view of a main portion showing the fixed-side block in the state of FIG. 3 and the movable-side block that faces the fixed-side block and is positioned at the top dead center. FIG. [Figure 5] 5 is an enlarged schematic cross-sectional view of a main part showing a state in which the deformable member is compressed between the fixed-side block and the movable-side block as the movable die moves to the bottom dead center in FIG. 4. FIG. [Figure 6] 6 is a cross-sectional view showing the deformed member in FIG. 5 after being plastically deformed by compression. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment will be described below with reference to the drawings. <Molding device 11> 1 and 2, a die device 11 is used, for example, for press working, and includes a fixed die 12 and a movable die 13 arranged opposite the fixed die 12 so as to be movable toward and away from the fixed die 12. In the die device 11 of this embodiment, the fixed die 12 and the movable die 13 are arranged opposite each other in the up-down direction (vertical direction). That is, the movable die 13 is arranged above the fixed die 12 and is configured to be able to reciprocate in the up-down direction.

[0012] At least one pair of opposing stroke end blocks 16 is provided on each of the fixed-side opposing surface 14 of the fixed die 12, which is the surface facing the movable die 13, and the movable-side opposing surface 15 of the movable die 13, which is the surface facing the fixed die 12. In this case, it is preferable to provide an even number of pairs of opposing stroke end blocks 16 on each of the fixed-side opposing surface 14 of the fixed die 12 and the movable-side opposing surface 15 of the movable die 13, taking into consideration the balance between the fixed die 12 and the movable die 13.

[0013] A circular fixed-side through-hole 17 is formed at one end of the fixed die 12, passing through the fixed die 12 in the vertical direction. A circular movable-side through-hole 18 is formed in the movable die 13 at a position opposite the fixed-side through-hole 17. A cylindrical guide bushing 19 is inserted and fixed into the movable-side through-hole 18. The lower end of a cylindrical guide post 20 is inserted and fixed into the fixed-side through-hole 17.

[0014] The upper end of the guide post 20 is inserted into the guide bushing 19 and is in sliding contact with the inner surface of the guide bushing 19. When the movable die 13 moves in the vertical direction to approach and move away from the fixed die 12, the inner surface of the guide bushing 19 slides on the circumferential surface of the guide post 20, thereby guiding the movable die 13. The movable die 13 is moved in the vertical direction between the top dead center (the position shown in FIG. 1) and the bottom dead center (the position shown in FIG. 2) by the driving force of a driving unit (not shown).

[0015] When the movable die 13 is at the top dead center, the opposing pair of stroke end blocks 16 are separated from each other. On the other hand, when the movable die 13 is at the bottom dead center, the opposing pair of stroke end blocks 16 are in contact with each other.

[0016] <Stroke end block 16> Two pairs of stroke end blocks 16 are provided opposite each other on the fixed-side opposing surface 14 of the fixed die 12 and the movable-side opposing surface 15 of the movable die 13, and both have a cylindrical shape with an axis extending in the vertical direction. Of these two stroke end blocks 16, one provided on the fixed die 12 side is referred to as a fixed-side block 21, and the other provided on the movable die 13 side is referred to as a movable-side block 22.

[0017] 1 and 3, a linearly extending groove 24 as an example of a recess is formed in the tip surface 23 of the fixed-side block 21. The groove 24 passes through the center of the tip surface 23, and both ends extend to the periphery of the tip surface 23. A deformable member 25 is disposed in the groove 24. The deformable member 25 is sandwiched between the fixed-side block 21 and the movable-side block 22 that constitute a pair of opposing stroke end blocks 16 and is compressed to undergo plastic deformation.

[0018] <Method for grasping bottom dead center of movable die 13 in die device 11> Generally, the bottom dead center of the movable die 13 deviates from its normal position due to heat accumulation caused by continuous operation of the die device 11, changes in the outside air temperature, and the like. The normal position of the bottom dead center of the movable die 13 is the position where the tip surface 26 of the movable-side block 22 contacts the tip surface 23 of the fixed-side block 21, as shown in FIG. 2. If the bottom dead center of the movable die 13 deviates from its normal position, machining defects by the die device 11 increase, so it is necessary to appropriately correct the bottom dead center of the movable die 13. However, in order to accurately correct the bottom dead center of the movable die 13, it is necessary to accurately determine the bottom dead center of the movable die 13.

[0019] Therefore, the method for determining the bottom dead center of the movable die 13 in the die device 11 includes a positioning step, a compression step, a measurement step, and a calculation step. That is, the method for determining the bottom dead center of the movable die 13 in the die device 11 accurately determines the bottom dead center of the movable die 13 in the die device 11 by sequentially performing the positioning step, compression step, measurement step, and calculation step.

[0020] 3 and 4, in the placement step, a deformable member 25 that undergoes plastic deformation when compressed and has a maximum width greater than the depth B of the groove 24 is placed in the groove 24 so that a portion of the deformable member 25 protrudes from the groove 24. The deformable member 25 is made of, for example, a ductile metal wire that is circular in cross section. In this embodiment, the deformable member 25 is made of, for example, solder.

[0021] In this embodiment, the outer diameter A of the deformable member 25 is set to 1.0 mm, for example. Therefore, the maximum width of the deformable member 25 is 1.0 mm. In this embodiment, the length of the deformable member 25 is slightly longer than the length of the groove 24, but it may be the same as the length of the groove 24 or may be shorter than the length of the groove 24.

[0022] In this embodiment, the depth B of the recessed groove 24 is set to 0.5 mm, for example. Therefore, when the deformable member 25 is placed in the recessed groove 24 in a lying state so as to follow the recessed groove 24, 0.5 mm, which is half of the radial extent of the deformable member 25, protrudes from the recessed groove 24 in the radial direction of the deformable member 25.

[0023] <Compression process> 5, in the compression step, the movable die 13 is moved to the bottom dead center, and the deformable member 25 placed in the groove 24 is sandwiched and compressed between the fixed-side block 21 and the movable-side block 22, thereby causing plastic deformation. Thereafter, the movable die 13 is moved to the top dead center.

[0024] <Measurement process> As shown in FIG. 6, in the measurement step, the thickness C in the compression direction of the deformed member 25 plastically deformed in the compression step is measured using, for example, a micrometer (not shown).

[0025] <Calculation process> 4 to 6, in the calculation step, the bottom dead center of the movable die 13 is calculated based on the thickness C of the deformable member 25 measured in the measurement step. That is, in the calculation step, the amount of deviation of the current bottom dead center of the movable die 13 from the correct position is calculated based on the thickness C of the deformable member 25 measured in the measurement step. The deviation amount D of the bottom dead center of the movable die 13 from the correct position is the value obtained by subtracting the depth B of the groove 24 from the thickness C of the deformable member 25 measured in the measurement step.

[0026] For example, if the thickness C of the deformable member 25 measured in the above measurement step is 0.8 mm, the depth B of the recessed groove 24 is 0.5 mm, and therefore the deviation D of the bottom dead center of the movable die 13 from the normal position is 0.8-0.5=0.3 mm. Also, if the thickness C of the deformable member 25 measured in the above measurement step is 0.5 mm, the deviation D of the bottom dead center of the movable die 13 from the normal position is 0.5-0.5=0.0 mm. In other words, in this case, the bottom dead center of the movable die 13 is not deviated from the normal position at all.

[0027] In this way, the bottom dead center of the movable die 13 can be determined with greater accuracy by calculating the deviation D from the normal position of the bottom dead center of the movable die 13 based on the actual measurement value of the thickness C in the compression direction of the deformed member 25 that has been plastically deformed in the compression process.

[0028] <Operation of the embodiment> In the above-described method for determining the bottom dead center of the movable die 13 in the die device 11, if the deviation amount D from the normal position of the bottom dead center of the movable die 13 is not 0.0 mm, the position of the movable die 13 in the die device 11 is adjusted so that the deviation amount D becomes 0.0 mm. This reduces processing defects caused by the die device 11.

[0029] It is preferable to adjust the position of the movable mold 13 of the mold device 11 based on the above-mentioned method for determining the bottom dead center of the movable mold 13 in the mold device 11 at an appropriate time, such as before using the mold device 11, when the mold device 11 has been operated continuously for a predetermined period of time, or when the outside air temperature has changed significantly.

[0030] <Effects of the embodiment> According to the embodiment described above in detail, the following effects are achieved. (1) The method for determining the bottom dead center of the mold device 11 includes an arrangement step of arranging a deformable member 25, which undergoes plastic deformation when compressed and has an outer diameter A larger than the depth B of the groove 24, in the groove 24 so that a portion of the member protrudes from the groove 24; a compression step of moving the movable mold 13 to the bottom dead center and compressing the deformable member 25 between a pair of stroke end blocks 16 to plastically deform it; a measurement step of measuring the thickness C in the compression direction of the deformable member 25 plastically deformed in the compression step; and a calculation step of calculating the bottom dead center of the movable mold 13 based on the thickness C of the deformable member 25 measured in the measurement step.

[0031] According to the above method, the bottom dead center of the movable die 13 is calculated based on the actual measured value of the thickness C in the compression direction of the deformed member 25 that has been plastically deformed in the compression process, so that the bottom dead center of the movable die 13 can be determined with higher accuracy.

[0032] (2) In the method for grasping the bottom dead center of the mold device 11, the linearly extending groove 24 is employed as the recess. According to the above method, a wire having a constant outer diameter A can be used as the deformable member 25, which makes it easy to handle the deformable member 25.

[0033] <Example of change> The above embodiment can be modified as follows: Furthermore, the above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0034] The recessed portion is not limited to the recessed groove 24, but may be formed by a depression. The deformable member 25 may be made of a wire rod having an elliptical or polygonal cross section, for example. The deformable member 25 is not limited to being linear, but may be spherical or rectangular.

[0035] The deformable member 25 may be made of a ductile metal other than solder. That is, the deformable member 25 may be made of, for example, copper, aluminum, zinc, or the like. If the outer diameter A of the deformable member 25 is larger than the depth B of the groove 24, the outer diameter A and the depth B of the groove 24 may be changed as appropriate.

[0036] The shape of the stroke end block 16 is not limited to a cylindrical shape, but may be an elliptical cylindrical shape, a polygonal cylindrical shape, or the like. The mold assembly 11 may be configured to include only a pair of stroke end blocks 16 facing each other.

[0037] The mold device 11 may be configured such that the fixed mold 12 and the movable mold 13 are arranged opposite each other in the horizontal direction. [Explanation of symbols]

[0038] 11...Molding equipment 12…Fixed type 13…Movable type 14...Facing surface of fixed side 15...Facing surface of the movable side 16...Stroke end block 17…Fixed side through hole 18...Movable side through hole 19...Guide bushing 20...Guidepost 21...Fixed side block 22... Movable block 23,26…Tip surface 24...Groove as an example of a recess 25...Deformable member A...Outer diameter B: Depth C: Thickness D: Amount of deviation

Claims

1. A method for grasping a bottom dead center of a mold apparatus including a fixed mold, a movable mold arranged to face the fixed mold and be movable toward and away from the fixed mold, and at least a pair of stroke end blocks opposed to each other and provided on a surface of the fixed mold facing the movable mold and a surface of the movable mold facing the fixed mold, respectively, comprising: A recess is formed on a tip surface of one of the pair of stroke end blocks provided on the fixed die, an arrangement step of arranging a deformable member that is plastically deformed by compression and has a maximum width greater than the depth of the recess in the recess so that a portion of the deformable member protrudes from the recess; a compression step in which the movable die is moved to a bottom dead center, and the deformable member is sandwiched between the pair of stroke end blocks and compressed to plastically deform the deformable member; a measuring step of measuring a thickness in a compression direction of the deformed member plastically deformed in the compression step; a calculation step of calculating a bottom dead center of the movable die based on the thickness of the deformable member measured in the measurement step; A method for determining the bottom dead center of a mold apparatus, comprising:

2. 2. The method for determining the bottom dead center of a mold apparatus according to claim 1, wherein the recess is a groove extending linearly.

3. A mold apparatus comprising: a fixed mold; a movable mold arranged to face the fixed mold and be movable toward and away from the fixed mold; and at least a pair of stroke end blocks opposed to each other, the stroke end blocks being provided on a surface of the fixed mold facing the movable mold and a surface of the movable mold facing the fixed mold, respectively, A mold apparatus characterized in that a recess is formed on the tip surface of the stroke end block provided on the fixed mold, in which a deformable member that is plastically deformed by being sandwiched and compressed between a pair of the stroke end blocks is placed.

Images