shaped plate

Abstract

The objective is to prevent plastic deformation of the mating portion in a mold where multiple mold segments are stacked in the thickness direction. [Solution] The present invention relates to a fixed mold plate 24 in which a plurality of mold plate segments 25, 26 are stacked in the thickness direction TD. In the present invention, the fixed mold plate 24 is provided with multiple fitting protrusions and multiple fitting recesses alternately in the radial direction on the sides of the mold plate segments 25 and 26 adjacent to each other in the thickness direction TD. The interlocking structure, in which multiple interlocking protrusions and multiple interlocking recesses are fitted together, preferably has a concentric annular or arc shape that shares the central axis of the mold plate segment.

Description

Technical Field

[0001] The present invention relates to a platen for holding a mold used, for example, in injection molding.

Background Art

[0002] The platen consists of a fixed platen whose position is fixed during molding, and a movable platen that moves back and forth relative to the fixed platen. A fixed mold and a movable mold are respectively attached to the fixed platen and the movable platen, and a molten resin (injection molding machine) or molten metal (die casting machine), which is the material to be molded, is supplied to the cavity formed between the fixed mold and the movable mold.

[0003] In a mold clamping device, tie bars for mold clamping are arranged at the four corners of the fixed platen. When a compressive force is applied between the fixed platen and the movable platen via the tie bars, the four corners of the fixed platen are pulled toward the side of the movable platen, while the central portion of the fixed platen is pushed in the opposite direction by receiving the clamping force via the movable mold and the fixed mold. Therefore, the fixed platen is deformed so as to form a concave surface on the mounting surface of the fixed mold, and accordingly, the fixed mold is deformed. As a result, a gap is generated between the fixed mold and the movable mold, and resin enters this gap to form burrs, or resin leakage occurs through the gap, so that there may occur a problem that the quality of the molded product deteriorates.

[0004] In response to this problem, Patent Document 1 proposes dividing the fixed platen into a plurality in the thickness direction. That is, Patent Document 1 shows a structure having a die body, a tie bar holding portion formed to project from the die body at each corner portion of the die body and holding a tie bar, and a reinforcing portion that connects predetermined tie bar holding portions among the respective tie bar holding portions and is formed along the edge of the die body and projecting from the die body. In the second embodiment particularly shown in FIG. 7 of Patent Document 1, a structure in which a fitting portion of a fixed die and a fitting portion of a mold mounting die are fitted by inlay is proposed. It is disclosed in Patent Document 1 that by adopting this inlay structure, the positioning accuracy between the fixed die and the mold mounting die can be increased. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2009 / 107605 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] According to Patent Document 1, when a mold is attached and a clamping force is applied, the fixed die is pulled at its four corners toward the mold mounting die by the tie bars, and its central part is pressed by the mold, causing the surface on the side of the mold mounting die to bend inward. At this time, the surface of the fixed die toward the mold mounting die is compressed toward the center, so it is understood that the radial dimension of the fitting portion in the central part of the fixed die is reduced. Here, since the fitting portion of the mold mounting die is fitted into the fitting portion, the inner circumferential surface of the fitting portion and the outer circumferential surface of the fitting portion are crushed against each other, and there is a risk that one or both of the fitting portion and the fitting portion may undergo plastic deformation.

[0007] Based on the above, the present invention aims to prevent plastic deformation of the fitting portion in a mold in which multiple mold segments are stacked in the thickness direction. [Means for solving the problem]

[0008] The present invention relates to a mold in which a plurality of mold segments are stacked in the thickness direction, Multiple interlocking protrusions and multiple interlocking recesses are alternately provided in the radial direction on the opposing sides of adjacent mold segments in the thickness direction, allowing them to be fitted together.

[0009] The convex-concave structure in which multiple fitting protrusions and multiple fitting recesses are fitted together in the present invention is It is preferable that the mold plate segments share a central axis and form a concentric annular or arc shape with each other.

[0010] In one first-type panel segment and the other second-type panel segment stacked adjacent to each other, The first type plate segment is provided with a first fitting projection and a first fitting recess, The second type of panel segment comprises a second fitting projection and a second fitting recess, It is preferable that the clearance between the first inner wall surface provided on the radially central side of the first fitting projection and the second inner wall surface provided on the radially central side of the second fitting recess that faces and is fitted to the first fitting projection increases as it moves radially outward.

[0011] In the mold plate of the present invention, preferably, The first inner wall surfaces of each of the multiple first fitting protrusions are arranged at equal pitches in the radial direction. The multiple second inner wall surfaces in each of the multiple second fitting recesses that face and are fitted to the multiple first fitting protrusions are arranged at unequal pitches in the radial direction, with the pitch becoming smaller towards the radially outer side.

[0012] In the mold plate of the present invention, preferably, The second inner wall surfaces in each of the multiple second fitting recesses are arranged at equal pitches in the radial direction. The multiple first inner wall surfaces of each of the multiple first fitting protrusions that face and are fitted into the multiple second fitting recesses are arranged at unequal pitches in the radial direction, with the pitch becoming larger towards the radially outer side.

[0013] In the mold plate of the present invention, preferably, Multiple first inner wall surfaces in multiple first fitting protrusions are arranged at equal pitches in the radial direction. Multiple second inner wall surfaces in multiple second fitting recesses are arranged at equal pitches in the radial direction, and The radial pitch (SP2) of two adjacent first inner wall surfaces, starting from the radial center, It is greater than the radial pitch (MP2) of the two adjacent second inner wall surfaces, starting from the radial center. [Effects of the Invention]

[0014] According to the mold plate of the present invention, by providing a plurality of fitting convex portions and fitting concave portions that can be fitted to each other in the radial direction on the opposing sides of the mold plate segments adjacent in the thickness direction, it is possible to suppress plastic deformation of the fitting portions in the mold plate configured by being divided into a plurality in the thickness direction.

Brief Description of the Drawings

[0015] [Figure 1] It is a side view showing a schematic configuration of an injection molding apparatus according to an embodiment. [Figure 2] It is a side cross-sectional view showing a fixed mold plate according to an embodiment. [Figure 3] It is a side cross-sectional view (left) showing the first mold plate segment of the fixed mold plate in FIG. 2 and a plan view (right) of the fitting side with the second mold plate segment. [Figure 4] It is a side cross-sectional view (left) showing the second mold plate segment of the fixed mold plate in FIG. 2 and a plan view (right) of the fitting side with the first mold plate segment. [Figure 5] It is a side cross-sectional view (left) and a plan view (right) of the first mold plate segment showing a preferable dimensional relationship between the first mold plate segment and the second mold plate segment. [Figure 6] It is a view showing before deformation (left) and after deformation (right) of a fixed mold plate in which the first mold plate segment and the second mold plate segment are laminated. [Figure 7] It is a side cross-sectional view showing examples of mold plate segments with 3 layers (3L) and 4 layers (4L) of laminated sheets. [Figure 8] It is a side cross-sectional view showing a mold plate segment according to a modified example of the concavo-convex structure.

Modes for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described by taking an injection molding machine as an example while referring to the accompanying drawings. The fixed mold plate in the injection molding machine of the present embodiment aims to suppress plastic deformation of the fitting portions while laminating a plurality of mold plate segments.

[0017] 〔Overall Configuration: Refer to FIG. 1〕 As shown in Figure 1, the injection molding machine 1 according to this embodiment includes a plasticizing section 10 and a molding section 20.

[0018] [Plasticizing part 10: See Figure 1] The plasticizing unit 10 comprises a heating cylinder 11 and a discharge nozzle 13 provided at the front end of the heating cylinder 11. The plasticizing unit 10 also includes a screw rotatably mounted inside the heating cylinder 11 and a heater wrapped around the heating cylinder 11, although these are not shown in the figures. The pelletized raw material resin is supplied into the heating cylinder 11 via a raw material input hopper 15 provided in the heating cylinder 11. The screw is capable of moving forward and backward, as well as rotating in both forward and reverse directions, within the fixed position of the heating cylinder 11. The plasticizing unit 10 includes a drive source 17 for moving the screw forward or backward, and a drive source 18 for rotating the screw in both forward and reverse directions. The injection molding machine 1 performs resin injection molding by combining the forward or backward movement and forward or reverse rotation of the screw.

[0019] [Molded section 20: See Figure 1] The molding unit 20 includes a fixed mold 21 whose position is fixed and a movable mold 23 which can move forward and backward relative to the fixed mold 21. In the mold clamping state where the fixed mold 21 and the movable mold 23 are abutted together, a mold cavity is formed between the fixed mold 21 and the movable mold 23. The resin plasticized in the molding unit 20 is injected and filled into the mold cavity. The fixed mold 21 is attached to the fixed mold platen 24, and the movable mold 23 is attached to the movable mold platen 27. Multiple tie bars 33, for example four, are provided between the fixed mold platen 24 and the movable mold platen 27 to connect them, and mold clamping or mold opening is performed by applying pressure from, for example, a hydraulic cylinder 31 between the fixed mold platen 24 and the movable mold platen 27 via the tie bars 33 and split nuts 35. In addition, although not shown in the figures, a mold opening and closing mechanism is provided to move the movable mold platen 27 a large distance away from the fixed mold platen 24, and the molding section 20 is provided with ejector pins, etc., to eject the injection molded product out of the mold in the open state.

[0020] [Fixed panel 24, movable panel 27: Figures 2, 3, 4] The fixed mold plate 24 and the movable mold plate 27 in the molding section 20 each have a structure in which multiple mold plate segments are stacked in a separable manner. Specifically, the fixed mold plate 24 comprises a first mold plate segment 25 and a second mold plate segment 26 stacked with the first mold plate segment 25. The first mold plate segment 25 and the second mold plate segment 26 are stacked in a separable manner from each other by fasteners, for example, which are not shown in the figure. The movable mold plate 27 comprises a first mold plate segment 28 and a second fitting segment 29 stacked with the first mold plate segment 28. The fixed mold plate 24 will be described below with reference to the figure, but the first mold plate segment 28 and the second fitting segment 29 of the movable mold plate 27 have the same configuration as the first mold plate segment 26 and the second mold plate segment 27 and can achieve the same effect.

[0021] [Type 1 Panel Segment 25: See Figures 2 and 3] The first mold plate segment 25 has an external shape that is generally rectangular and comprises a non-fitting side 252 made of a flat surface, a fitting side 251 provided on the back side of the non-fitting side 252, and a side surface 253 connecting the non-fitting side 252 and the fitting side 251. When the first mold plate segment 25 and the second mold plate segment 26 are stacked, the fitting side 251 faces the fitting side 261 of the second mold plate segment 26. The first mold plate segment 25 includes a nozzle housing chamber 255 that penetrates the non-fitting side 252 and the fitting side 251. The nozzle housing chamber 255 consists of a substantially cylindrical void formed around the central part of the mold plate when the fitting side 251 is viewed from above, for example, around the central axis C.

[0022] On the mating side 251, the first-first mating projection P11, the first-second mating projection P12, and the first-third mating projection P13 are formed in order from the side of the central axis C. The first-first mating projection P11 to the first-third mating projection P13 are composed of annular protrusions that are continuous in the circumferential direction and have the same projection height from the reference surface PR1 of the mating side 251. On the mating side 251, the first-first mating recess D11 and the first-second mating recess D12 are formed sequentially from the side of the central axis C outward. For example, the first-first mating recess D11 to the first-second mating recess D12 are each flush with the reference surface PR1 of the mating side 251 and consist of annular grooves that are connected in the circumferential direction.

[0023] The 1-1 fitting projections P11 to 1-3 fitting projections P13 and the 1-1 fitting recesses D11 to 1-2 fitting recesses D12 are formed in order from the side of the central axis C. A reference surface PR1 is formed on the outside of the 1-3 fitting projection P13. As described above, the mating side 251 is provided with multiple mating protrusions and multiple mating recesses, which are alternately arranged from the inside to the outside in the radial direction RD. In this embodiment, the radial direction RD is shown as the outward direction with respect to the central axis C, but the reference for the radial direction RD is not limited to the central axis C, and any location near the central axis C in the center of the mold plate is acceptable. In the examples shown in Figures 2 and 3, the dimensions from the reference surface PR1 to the top surfaces of the 1st-1st fitting projections P11 to the 1st-3rd fitting projections P13 are the same, but the dimensions to the top surfaces may differ as long as stacking with the second type plate segment 26 is possible. This also applies to the dimensions from the reference surface PR2 to the top surfaces of the 2nd-1st fitting projections P21 to the 2nd-4th fitting projections P24 in the second type plate segment 26. The bottom surfaces of the 1st-1st fitting recesses D11 to the 1st-2nd fitting recesses D12 may also differ in dimensions from the reference surface PR1 as long as stacking with the second type plate segment 26 is possible.

[0024] [Type 2 panel segment 26: See Figures 2 and 4] The second type plate segment 26 has an external shape that is generally rectangular, and includes a non-fitting side 262 made of a flat surface, a fitting side 261 provided on the back side of the non-fitting side 262, and a side surface 263 connecting the non-fitting side 262 and the fitting side 261. The second type plate segment 26 includes a nozzle housing chamber 265 that penetrates the non-fitting side 262 and the fitting side 261. The nozzle housing chamber 265 consists of a substantially cylindrical void formed around its central axis C when the non-fitting side 262 (fitting side 261) is viewed from above.

[0025] On the mating side 262, the second-first mating projection P21, the second-second mating projection P22, the second-third mating projection P23, and the second-fourth mating projection P24 are formed in order from the side of the central axis C. The second-first mating projection P21 to the second-fourth mating projection P24 are composed of annular protrusions that are connected in the circumferential direction and have the same projection height. In this case, the projection heights of the second-first mating projection P21 to the second-fourth mating projection P24 may differ in dimensions to the top surface, as long as stacking with the first type plate segment 25 is possible, similar to the first-first mating projection P11 to the first-third mating projection P13 of the first type plate segment 25. On the mating side 262, the second-first mating recess D21, the second-second mating recess D22, and the second-third mating recess D23 are formed sequentially from the side of the central axis C outward. Each of the second-first to second-third mating recesses D21 to D23 is, for example, flush and composed of annular grooves that are continuous in the circumferential direction. Furthermore, the bottom surfaces of the second-first to second-third mating recesses D21 to D23 may not be flush with the reference surface PR2 and may have different dimensions, as long as stacking with the first type plate segment 25 is possible.

[0026] The 2-1 fitting projections P21 to 2-4 fitting projections P24 and the 2-1 fitting recesses D21 to 2-3 fitting recesses D23 are formed sequentially from the side of the central axis C outwards. As described above, the mating side 262 is provided with multiple mating protrusions and multiple mating recesses, which are alternately arranged from the inside to the outside in the radial direction RD.

[0027] [Matching state of the first type plate segment 25 and the first type plate segment 26: See Figure 2] The first type plate segment 25 and the first type plate segment 26 are fitted together at their respective mating sides 251 and 261. Specifically, the 1-1 mating projection P11 is fitted into the 2-1 mating recess D21, the 1-2 mating projection P12 is fitted into the 2-2 mating recess D22, and the 1-3 mating projection P13 is fitted into the 2-3 mating recess D23. In addition, the 2-1 mating projection P21 is fitted inside the 1-1 mating projection P11, the 2-2 mating projection P22 is fitted into the 1-1 mating recess D11, the 2-3 mating projection P23 is fitted into the 1-2 mating recess D12, and the 2-4 mating projection P24 is fitted into the 1-3 mating recess D13.

[0028] As described above, when the first type plate segment 25 and the second type plate segment 26 are stacked, multiple fitting protrusions and multiple fitting recesses are fitted alternately from the inside to the outside in the radial direction RD. In particular, the fitting at the part closest to the central axis C may or may not have a clearance (gap) between the protrusions and recesses, and if there is no clearance, the fitting may be such that stress is generated in the radial direction RD, like press fitting. As mentioned above, the first type plate segment 25 and the second type plate segment 26 are stacked so as to be separable in the thickness direction TD, but in order to maintain the stacked state, they are joined together, for example, by fastening means.

[0029] [effect] <First effect> The fixed mold plate 24 is divided into a first mold plate segment 25 and a second mold plate segment 26, and multiple interlocking protrusions and recesses are provided radially RD in the region connecting the two segments, allowing them to fit together. This allows the positional displacement of the interlocking parts due to the deflection of the boundary when the first mold plate segment 25 and the second mold plate segment 26 are stacked during mold clamping to be absorbed by the interlocking clearance, thereby reducing the crushing force on the interlocking parts and preventing plastic deformation of the interlocking parts. Furthermore, the deflection of the boundary when the first mold plate segment 25 and the second mold plate segment 26 are stacked during mold clamping can be distributed and held by the multiple interlocking parts, suppressing positional displacement of the interlocking parts and making the overall deflection rigidity of the mold plate equivalent to that of a conventional one-piece mold plate. As a result, the deformation of the mold during mold clamping can also be equivalent to that of a conventional one-piece mold plate, and molding can be performed without significantly changing the molding conditions from those of a conventional one-piece mold plate.

[0030] <Second effect> Tie bars 33 positioned at the four corners of the fixed platen 24 and the movable platen 27 pull the four corners of the fixed platen 24 and the movable platen 27 towards each other. As a result, when viewed from the side, the first platen segment 25 and the second platen segment 26 bend in a concave shape on the side where the fixed mold 21 and the movable mold 23 are positioned. In contrast, by making the convex and concave shapes concentric annular rings that share the central axis C of the first platen segment 25 and the second platen segment 26, the circumferential load distribution of the fitting portion of each convex and concave shape can be made more uniform, thereby preventing plastic deformation of the fitting portion.

[0031] <Third effect> By dividing the fixed mold plate 24 into a first mold plate segment 25 and a second mold plate segment 26, it becomes possible to transport the mold plate even when a single mold plate of the same dimensions would be too heavy and difficult to transport.

[0032] [Suitable examples of fitting clearance: See Figures 5 and 6] Although the fixed plate 24 shown in Figure 2 is depicted as having no gap (fitting clearance) between the fitting protrusions and fitting recesses, as will be explained below, plastic deformation can be more effectively prevented by suitably providing a fitting clearance. Here, fitting clearance refers to the gap between each pair of protrusions and recesses that directly fit together within a plurality of protrusions and recesses.

[0033] Figure 6 schematically shows the deformation behavior when a fixed mold plate 24, in which the first mold plate segment 25 and the second mold plate segment 26 are stacked without interlocking of protrusions and indentations, is clamped. The load point LP is generated by the compressive force of the tie bar 33, and the support point SP is generated by the fixed mold 21. When no deflection occurs, let points a and d be any two points on the first surface 25F of the first type plate segment 25, let points b and e be any two points on the contact surface between the second surface 25B of the first type plate segment 25 and the first surface 26F of the second type plate segment 26, and let points c and f be any two points on the second surface 26B of the second type plate segment 26. Note that the first surface 25F and the first surface 26F deform convex when deflection occurs in the fixed type plate 24, and the second surface 25B and the second surface 26B deform concave when deflection occurs in the fixed type plate 24 (first type plate segment 25, second type plate segment 26).

[0034] When deflection occurs in the first type plate segment 25 and the second type plate segment 26, points a to f are displaced. Here, at points b and e on the interface between the first type plate segment 25 and the second type plate segment 26, point b before deformation due to deflection is displaced to points b1 and b2 after deformation, and point e before deformation due to deflection is displaced to points e1 and e2 after deformation. For example, comparing the displacement amount α at point a with the displacement amount β at point d, α > β, and similarly comparing the displacement amount α at point c with the displacement amount β at point f, α > β. In other words, the closer you get to the outer periphery from the central axis C, the larger the displacement at any given point becomes, and line segment b1-b2 > line segment e1-e2.

[0035] The above results indicate that when the contact surfaces of the second surface 25B of the first type plate segment 25 and the first surface 26F of the second type plate segment 26 are interlocked in an uneven manner, the load exerted on the interlocking portion by the opposing forces—forces that cause points on the convex side of the surface to move outward due to deflection, and forces that cause points on the concave side of the surface to move along the central axis C—becomes larger for the interlocking portion on the outer side where the displacement is greater. Therefore, we propose a means to reduce this load exerted on the interlocking portion.

[0036] The essence of this proposal is to increase the fitting clearance δc at positions far from the central axis C (δc > δb) compared to the fitting clearance δb at positions close to the central axis C. More specifically, it is as follows: Let us take the following as examples: the outer fitting clearance δb in the radial RD at the fitting portion between the 1-1 fitting recess D11 in the 1st type plate segment 25 and the 2-2 fitting projection P22 in the 2nd type plate segment 26, and the outer fitting clearance δc in the radial RD at the fitting portion between the 1-2 fitting recess D12 in the 1st type plate segment 25 and the 2-3 fitting projection P23 in the 2nd type plate segment 26. The fitting clearance δb is the distance in the radial RD between the inner wall surface 26b of the 2-2 fitting recess D22 and the inner wall surface 25b of the 1-2 fitting projection P12. The fitting clearance δc is the distance in the radial RD between the inner wall surface 26c of the 2-3 fitting recess D23 and the inner wall surface 25c of the 1-3 fitting projection P13. Furthermore, inner wall surfaces 26b and 26c correspond to the second inner wall surface in the present invention, and inner wall surfaces 25b and 25c correspond to the first inner side surface in the present invention. In addition, "inside" in the inner side surface refers to the wall surface located on the side of the central axis C, that is, the side of the center in the radial direction RD.

[0037] Here, the second-second fitting recess D22 and the second-third fitting recess D23 are provided on a surface that deforms into a convex shape due to deflection, and the first-second fitting protrusion P12 and the first-third fitting protrusion P13 are provided on a surface that deforms into a concave shape due to deflection. Therefore, the relationship δc > δb means that the clearance between the inner wall surface of the recess on the surface that becomes convex due to deflection and the inner wall surface of the protrusion on the surface that engages with this recess and becomes concave due to deflection becomes larger as the engagement portion on the outer circumference increases.

[0038] By setting δc > δb, the condition in which the outer circumference makes stronger contact can be mitigated, reducing the difference in pushing load between the center and the outer circumference, thereby preventing the occurrence of localized uneven loads, and allowing the load shared by multiple mating parts to be distributed evenly. As a result, plastic deformation can be suppressed in the outer mating parts where the load is greater, such as the 1st-2nd mating recess D12 and the 2nd-3rd mating protrusion P23.

[0039] The fitting clearance relationship described above is such that the arrangement of radial RDs of the protrusions and recesses of one first mold segment 25 is at equal pitch, while the arrangement of radial RDs of the protrusions and recesses of the other second mold segment 26 is at unequal pitch, and this unequal pitch increases towards the outer edges of the radial RDs. Alternatively, the arrangement of radial RDs of the protrusions and recesses of the first mold segment 25 and the second mold segment 26 is at equal pitch, and at the respective fitting surfaces of the first mold segment 25 and the second mold segment 26 that have interlocking protrusions and recesses, the pitch of the arrangement of radial RDs of the protrusions and recesses of one mold segment whose interlocking surface deforms concave during mold clamping is made larger than the pitch of the arrangement of radial RDs of the protrusions and recesses of the other mold segment whose interlocking surface deforms convex during mold clamping. By doing so, the load on the outer interlocking part is relatively reduced and the load on the central side is increased, so that the load on the interlocking part due to the protrusions and recesses of the radial RDs can be made more uniform.

[0040] Applying the above pitch relationships to the example in Figure 5, there are three possible cases. In Case 1, the pitches (SP2-, SP1) of the inner wall surfaces located on the side of the central axis C, i.e., the radial center side, of the multiple first fitting protrusions are equal in the radial direction RD, while the pitches (MP2, MP1) of the inner wall surfaces located in the multiple second fitting recesses are unequal in the radial direction RD, with the outer pitch being smaller. Furthermore, in Case 2, the pitches (MP2, MP1) of the multiple inner wall surfaces located on the side of the central axis C in the multiple second fitting recesses are equal, while the pitches (SP2, SP1) of the respective inner wall surfaces located on the side of the central axis C in the multiple first fitting protrusions are unequal in the radial direction RD, with the outermost protrusion being larger. Furthermore, in Case 3, the pitch of the multiple inner wall surfaces in each of the multiple first fitting protrusions and the pitch of the inner wall surfaces in each of the multiple second fitting recesses are equal, and the pitch (SP2) in the radial RD of the two first inner wall surfaces arranged sequentially from the central axis C is greater than the pitch (MP2) in the radial RD of the two second inner wall surfaces arranged sequentially from the central axis C. MP1, MP2, SP1, and SP2 are specified by the dimensions shown in Figure 5, specifically as follows. Also, for simplicity, in both the first type plate segment 25 and the second type plate segment 26, the thickness of each ridge and groove arranged radially are the same.

[0041] Case 1; MP2 > MP1 and SP2 = SP1 Case 2; MP2 = MP1 and SP2 < SP1 Case 3; MP2 = MP1 and SP2 = SP1 and SP2 > MP2 MP2 = Radial dimension (RD) from inner wall surface 26a to inner wall surface 26b MP1 = Radial dimension (RD) from inner wall surface 26b to inner wall surface 26c SP2 = Radial dimension (RD) from inner wall surface 25a to inner wall surface 25b SP1 = Radial dimension (RD) from inner wall surface 25b to inner wall surface 25c

[0042] In the fixed platen 24 shown in Figure 5, the mating portions closest to the central axis C (25a and 26a) are preferably constructed with a spigot structure, and the mating clearance δi is preferably about 0 to 0.5 mm. A mating clearance δi of 0 mm applies when the first platen segment 25 and the second platen segment 26 are press-fitted. Furthermore, for δi, δb, and δc in Figure 5, it is preferable that they be within the following ranges for mold plates of clamping devices with a clamping force of 3000 tons or more. However, the appropriate values ​​of the fitting clearances δi, δb, and δc are greatly influenced by the dimensions of the mold, mold plate dimensions, and the arrangement of the interlocking parts (especially the distance from the central axis C), and are not limited to the following values. δb=δi+(0.1~0.3)mm, δc=δb+(0.2~0.5)mm

[0043] [Number of layers: See Figure 7] The above example of a fixed panel 24 shows a two-layer design consisting of a first panel segment 25 and a second panel segment 26. However, the present invention can also be divided into three layers, such as a first panel segment 25, a second panel segment 26, and a third panel segment 27, or into four layers, such as a first panel segment 25, a second panel segment 26, a third panel segment 27, and a fourth panel segment 28.

[0044] [Example of an arc: Figure 8(a)] In the fixed mold plate 24 described above, the 1-1 fitting protrusions P11 to 1-3 fitting protrusions P13 and 1-1 fitting recesses D11 to 3 fitting recesses D13 in the first mold plate segment 25, and the 2-1 fitting protrusions P21 to 2-3 fitting protrusions P23 and 2-1 fitting recesses D21 to 2-3 fitting recesses D23 in the second mold plate segment 26 are all intended to be annular shapes made of perfect circles. Furthermore, if the deflection of the mold plate is not a uniform, symmetrical deflection, the annular shape may be an elliptical shape to match the manner of deflection. The present invention is not limited to this, and as shown in Figure 8(a), the 1-4 fitting protrusions P14 to 1-6 fitting protrusions P16 and 1-4 fitting recesses D14 to 1-6 fitting recesses D16 can also be made into arc shapes. In other words, the present invention also allows for the intermittent provision of the 1st to 4th fitting protrusions P14 to the 1st to 6th fitting protrusions P16 and the 1st to 4th fitting recesses D14 to the 1st to 6th fitting recesses D16 in the circumferential direction. Here, the first type plate segment 25 has been described, but in the second type plate segment 26 which is stacked with the first type plate segment 25, the 2nd to 4th fitting protrusions P24 to the 2nd to 6th fitting protrusions P26 and the 2nd to 4th fitting recesses D24 to the 2nd to 6th fitting recesses D26 can also be provided intermittently in the circumferential direction.

[0045] [Example of a polygon: Figure 8(b)] In the fixed-type panel 24 described above, the 1-1 fitting projections P11 to 1-3 fitting projections P13 and 1-1 fitting recesses D11 to 1-3 fitting recesses D13 in the first-type panel segment 25, and the 2-1 fitting projections P21 to 2-3 fitting projections P23 and 2-1 fitting recesses D21 to 2-3 fitting recesses D23 in the second-type panel segment 26, are all annular or arc-shaped. The present invention is not limited to this, and as shown in Figure 8(b), the 1st to 7th fitting protrusions P17 to the 1st to 9th fitting protrusions P19 and the 1st to 7th fitting recesses D17 to the 1st to 9th fitting recesses D19 can also be made polygonal. Although not shown, in the 2nd type plate segment 26 which is stacked with the 1st type plate segment 25, the 1st to 7th fitting protrusions P17 to the 1st to 9th fitting protrusions P19 and the 1st to 7th fitting recesses D17 to the 1st to 9th fitting recesses D19 can also be provided in a polygonal shape in the circumferential direction. When fitting protrusions and fitting recesses are provided in a polygonal shape, the radial direction (RD) is defined as the radial direction of the inscribed or circumscribed circle of the polygon. In other words, in a mold segment where fitting protrusions and fitting recesses are provided in a polygonal shape, for example, the "radial direction" of "multiple first inner wall surfaces provided on the radially central side" is determined based on the diameter of the inscribed or circumscribed circle.

[0046] In addition to the above, it is possible to select or replace the configurations listed in the above embodiments, or to change them to other configurations as appropriate, as long as they do not deviate from the spirit of the present invention. For example, in this embodiment, the wall shape of the convex and concave parts is shown as a rectangle, but the wall shape of the convex or concave part is not limited to a rectangle, and the wall shape of either or both of the convex or concave parts can be a known screw thread wall shape (e.g., tapered shape or sawtooth shape) or a known gear wall shape (e.g., involute curve shape or cycloid curve shape). [Explanation of symbols]

[0047] 1 injection molding machine 10 Plasticizing part 11 Heating tube 13 Discharge nozzle 15 Raw material input hopper 17,18 Power source 20 Molding section 21 Fixed mold 23. Movable mold 24 Fixed board 25. Type 1 Panel Segment 25F 1st page 25B 2nd side 25a,25b,25c Inner wall surface 26. Type 2 Panel Segment 26F 1st page 26B 2nd side 26a, 26b, 26c Inner wall surface 27 Movable mold board 28. Type 1 Panel Segment 29. Type 2 Panel Segment 31 Hydraulic Cylinder 33 Tie Bar 35 split nuts 251 Mating side 252 Non-mating side 253 Side view 255 Nozzle housing chamber 261 Mating side 262 Non-fitting side 263 Side view 265 Nozzle housing chamber

Claims

1. A mold in which multiple mold segments are stacked in the thickness direction, A mold in which a plurality of fitting protrusions and a plurality of fitting recesses, which can be fitted together, are alternately provided in the radial direction on the opposing sides of the mold segments adjacent to each other in the thickness direction.

2. The convex-concave structure in which the multiple fitting protrusions and the multiple fitting recesses are fitted together is The aforementioned plate segment shares a central axis and forms a concentric ring-shaped or arc-shaped structure with respect to each other. The mold according to claim 1.

3. In a first type plate segment and a second type plate segment stacked adjacent to each other, The first type plate segment comprises a first fitting projection and a first fitting recess, The second type of panel segment comprises a second fitting projection and a second fitting recess, The clearance between the plurality of first inner wall surfaces provided on the radially central side of the plurality of first fitting protrusions and the plurality of second inner wall surfaces provided on the radially central side of the plurality of second fitting recesses that face and are fitted to the first fitting protrusions is larger towards the radially outer side. A mold according to claim 1 or claim 2.

4. The first inner wall surfaces of each of the multiple first fitting protrusions are arranged at equal pitches in the radial direction. The second inner wall surfaces of each of the multiple second fitting recesses that face and are fitted to the multiple first fitting protrusions are arranged at an unequal pitch in the radial direction, with the pitch becoming smaller towards the outer side in the radial direction. The mold according to claim 3.

5. The second inner wall surfaces in each of the multiple second fitting recesses are arranged at equal pitches in the radial direction. The first inner wall surface of each of the multiple first fitting protrusions that face and are fitted into the multiple second fitting recesses is arranged with an unequal pitch in the radial direction, and the pitch is larger towards the outer side in the radial direction. The mold according to claim 3.

6. The multiple first inner wall surfaces of the multiple first fitting protrusions are arranged at equal pitches in the radial direction. The multiple second inner wall surfaces in the multiple second fitting recesses are arranged at equal pitches in the radial direction, The radial pitch of the two first inner wall surfaces, which are arranged sequentially from the center in the radial direction, The pitch of the two second inner wall surfaces arranged sequentially from the center in the radial direction is greater than the pitch of the two second inner wall surfaces in the radial direction. The mold according to claim 3.

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