Rubber product molding molds

Abstract

To reduce material loss.SOLUTION: A mold 10 for molding a rubber product comprises: an upper mold 11; a lower mold 12 that forms a cavity space S1 for molding the product between itself and the upper mold 11; and an annular burr mold 30 provided around the upper mold 11 and the lower mold 12, and having a cavity space 301 for a burr that communicates to the cavity space S1 for molding the product in a state in which the upper mold 11 and the lower mold 12 are closed. On a peripheral portion of the lower mold 12, an inner blade 12a1 is provided, and on a portion arranged along an edge of the upper mold 11 of the burr mold 30, an outer blade 302 is provided.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a mold for molding rubber products. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2016-104541 discloses a rubber molding die having a pair of dies with opposing surfaces. The rubber molding die in this publication molds multiple rubber products connected by a molding sheet. Each rubber product is then separated from the molding sheet using a punching blade. One of the dies has a cylindrical cavity recessed from the opposing surface to mold a cylindrical rubber product. Furthermore, a circular groove recessed in a ring shape surrounding the cavity and concentric with the cavity is formed. This circular groove forms a circular convex wall for guiding the cutting blade, which engages with the outside of the cutting blade when the rubber product is set on the punching blade. The publication states that this configuration allows the rubber product to be smoothly separated from the molding sheet and reduces the occurrence of defects in the separated rubber product. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-104541 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a plurality of pieces are molded simultaneously from a molding sheet, a large portion of the molding sheet does not end up in the final product and is discarded, resulting in a large amount of material loss. [Means for solving the problem]

[0005] The mold for molding a rubber product disclosed herein includes a first mold, a second mold that is placed on top of the first mold to form a product molding cavity space between the first mold and the second mold, and an annular burr mold that is provided around the first mold and the second mold and has a burr cavity space that communicates with the product molding cavity space when the first mold and the second mold are closed. An inner cutter is provided on the periphery of the second mold. An annular outer cutter corresponding to the inner cutter is provided on a portion of the burr mold that is located along the edge on the first mold side.

[0006] The mold for molding rubber products disclosed herein reduces material waste and also makes it easier to remove burrs after molding. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view that schematically shows a mold 10 for molding rubber products. [Figure 2] FIG. 2 is a perspective view of a molded product 200 molded by the mold 10. As shown in FIG. [Figure 3] FIG. 3 is a schematic cross-sectional view of a mold 10 for molding rubber products. [Figure 4] FIG. 4 is a plan view of the locking member 40 attached to the frame 53c. [Figure 5] FIG. 5 is a side view of the locking member 40. As shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view of the intermediate holder 52. [Figure 7] FIG. 7 is a cross-sectional view showing a state in which the first burr die 31 is attached to the intermediate holder 52 and the lower holder 53. As shown in FIG. [Figure 8] FIG. 8 is a cross-sectional view showing a state in which the second burr die 31 is attached to the intermediate holder 52 and the lower holder 53. As shown in FIG. [Figure 9] FIG. 9 is a cross-sectional view of a mold 10 for molding rubber products. [Figure 10] FIG. 10 is an enlarged cross-sectional view of the burr mold 30. [Figure 11]FIG. 11 is a cross-sectional view of a mold 10 for molding rubber products. [Figure 12] FIG. 12 is a cross-sectional view of a mold 10 for molding rubber products. [Figure 13] FIG. 13 is a cross-sectional view of a mold 10 for molding rubber products. [Figure 14] FIG. 14 is a cross-sectional view of a mold 10 for molding rubber products. [Figure 15] FIG. 15 is a cross-sectional view of a rubber product molding die 10A. DETAILED DESCRIPTION OF THE INVENTION

[0008] The disclosure herein will be described below with reference to the drawings. Note that the present disclosure is not limited to the following disclosure. Each drawing is a schematic drawing and does not necessarily reflect the actual product. Furthermore, each drawing does not limit the present invention. Furthermore, components and parts that perform the same function are appropriately designated by the same reference numerals, and duplicate explanations will be omitted.

[0009] <Rubber product molding mold 10> 1 is a cross-sectional view that schematically shows a rubber product molding die 10. In each drawing, hatching that should be applied to cross sections has been appropriately omitted.

[0010] <Rubber product molding mold> The mold 10 for molding rubber products will be referred to as the "mold 10" where appropriate. As shown in Fig. 1, the mold 10 includes an upper mold 11 as a first molding mold, a lower mold 12 as a second molding mold, a flash mold 30, and a locking member 40. The upper mold 11, the lower mold 12, the flash mold 30, and the locking member 40 are set in a die set 50. Fig. 1 shows a state in which an upper holder 51 to which the upper mold 11 is attached is raised, and the upper mold 11 and the lower mold 12 are opened.

[0011] <Molded products 200> 2 is a perspective view of a molded article 200 formed by the mold 10. In this embodiment, the molded article 200 is a substantially cylindrical member, which is a medical rubber stopper with a hole formed in the center. The molded article 200 may also be a gasket to be attached to the tip of a syringe piston. Here, examples of the molded article 200 include a medical rubber stopper and a gasket to be attached to the tip of a syringe piston, but the molded article is not limited to these.

[0012] <Preformed product 220> The preform 220 is made of a predetermined amount of unvulcanized rubber composition and can be prepared, for example, by being preformed into a shape corresponding to the molded article 200. As shown in Fig. 1, the preform 220 is set on the lower mold 12 with the mold 10 in an open state. The preform 220 is vulcanized and molded by heating with the upper mold 11 and the lower mold 12 closed.

[0013] Die Set 50 The die set 50 includes an upper holder 51, an intermediate holder 52, and a lower holder 53. The intermediate holder 52 is disposed between the upper holder 51 and the lower holder 53. The upper holder 51, the intermediate holder 52, and the lower holder 53 are each a plate-shaped member. The upper holder 51, the intermediate holder 52, and the lower holder 53 face each other vertically. Although not shown, the upper holder 51 and the intermediate holder 52 are configured to be guided by guides and move up and down in a direction perpendicular to the lower holder 53. The upper holder 51 and the intermediate holder 52 are operated via an actuator 82 and a control device 80.

[0014] As shown in Fig. 1, the upper holder 51 has a recess 51a in the center of its underside, to which the upper die 11 is attached. Fig. 3 is a schematic cross-sectional view of the rubber product molding die 10. Fig. 3 shows the rubber product molding die 10 shown in Fig. 1 with the intermediate holder 52, flash die 30, and locking member 40 removed. Fig. 4 is a plan view of the locking member 40 attached to a frame 53c. In Fig. 4, parts of the locking member 40 and frame 53c in the circumferential direction are broken away.

[0015] The lower holder 53 is a member that serves as the base of the mold 10. A recess 53a is formed in the center of the upper surface of the lower holder 53. In this embodiment, the recess 53a has a cylindrical inner peripheral surface. A spring seat member 53b and a frame 53c are installed in the recess 53a. The spring seat member 53b is a disk-shaped member that is fixed to the bottom of the recess 53a.

[0016] The frame 53c is a substantially cylindrical member having an outer shape corresponding to the recess 53a of the lower holder 53. The frame 53c is housed in the recess 53a of the lower holder 53. The upper portion of the side surface of the frame 53c is recessed inward, and a gap 53e into which the locking member 40 is attached is formed between the side surface of the frame 53c and the inner surface of the recess 53a of the lower holder 53. In this embodiment, the gap 53e is a cylindrical space. Four elongated holes 53c1 that are inserted into the gaps 53e are formed in the side surface of the upper portion of the frame 53c and extend circumferentially.

[0017] The frame 53c has a disk-shaped upper surface 53c2 at its upper end. An opening 53c3 is formed in the center of the upper surface 53c2. Around the opening 53c3, a shaft insertion hole 53c4 through which the guide shaft 35 of the first burr die 31 is inserted and a shaft insertion hole 53c5 through which the guide shaft 36 of the second burr die 32 is inserted are formed. In this embodiment, as shown in Fig. 4, the shaft insertion holes 53c4, 53c5 are arranged in a total of four around the circumference, offset by 45 degrees in the circumferential direction.

[0018] <Locking member 40> FIG. 5 is a side view of the locking member 40. The locking member 40 is a component of the locking mechanism 400 that maintains the first burr die 31 and the second burr die 32 in an open state. In FIG. 5, the right side of the locking member 40 is shown partially cut away. The locking member 40 is a generally cylindrical member. As shown in FIG. 1, the locking member 40 is coaxially mounted in the gap 53e between the inner surface of the recess 53a of the lower holder 53 and the outer circumferential surface of the frame 53c. Four shaft members 41 are mounted on the side circumferential surface 40a of the locking member 40 at equal intervals in the circumferential direction so as to protrude inward. Each shaft member 41 is mounted to pass through the elongated hole 53c1 and has a length that protrudes inward of the frame 53c through the elongated hole 53c1. The locking member 40 is rotatable about its axis relative to the frame 53c within the recess 53a of the lower holder 53, and when the locking member 40 rotates, the shaft member 41 moves in the circumferential direction along the elongated hole 53c1. The shaft member 41 is a member for operating the locking and unlocking of the first burr die 31. The range of rotation of the locking member 40 is determined by the circumferential length of the elongated hole 53c1.

[0019] The elongated holes 53c1 are formed at a predetermined height on the frame 53c so that the shafts 41 protruding inward from the frame 53c can support the lower base member 37 (described later) from below at a predetermined height. The shafts 41 are movable along the elongated holes 53c1 between position (A) where they abut the underside of the lower base member 37 and position (B) where they overlap with notches 37c formed in the lower base member 37. The notches 37c are formed with dimensions larger than the shafts 41 protruding inward from the frame 53c. Note that in FIG. 4, the state in which the shafts 41 have been moved to position (B) is shown by solid lines, and the shafts 41 moved to position (A) are shown by two-dot chain lines. When the shafts 41 have been moved to position (B), the notches 37c of the lower base member 37 and the shafts 41 overlap in the vertical direction, eliminating interference between the lower base member 37 and the shafts 41. Therefore, the lower base member 37 can move above and below the shaft member 41 .

[0020] 6 is a cross-sectional view of the intermediate holder 52. As shown in FIGS. 1 and 6, the intermediate holder 52 is disposed between the lower holder 53 and the upper holder 51. The lower mold 12 is attached to the center of the intermediate holder 52.

[0021] FIG. 7 is a cross-sectional view showing a state in which the first burr die 31 is attached to the intermediate holder 52 and the lower holder 53. FIG. 8 is a cross-sectional view showing a state in which the second burr die 31 is attached to the intermediate holder 52 and the lower holder 53. In FIG. 7, the second burr die 32 and the locking member 40 are omitted from FIG. 1. In FIG. 8, the first burr die 31 is omitted from FIG. 1. FIG. 9 is a cross-sectional view of the rubber product molding mold 10. In FIG. 9, the upper holder 51 is lowered from the state shown in FIG. 1, and the upper die 11 and the lower die 12 are closed. FIG. 10 is an enlarged cross-sectional view of the burr die 30 and its vicinity in FIG. 9. As shown in FIGS. 9 and 10, when the upper die 11 and the lower die 12 are closed, the burr die 30 is also closed.

[0022] As shown in FIG. 6, the casing 521 is a substantially cylindrical member with a bottom. The casing 521 is attached to the intermediate holder 52 with bolts, with a bottom 521d at one end of the cylindrical portion positioned downward. Four shaft insertion holes 521d1 and 521d2 are formed in the bottom 521d of the casing 521, alternately spaced 45 degrees apart in the circumferential direction so as to overlap the shaft insertion holes 53c4 and 53c5 formed in the upper surface 53c2 of the frame 53c. As shown in FIG. 7, the guide shaft 35 of the first burr die 31 is inserted through the shaft insertion hole 521d1. As shown in FIG. 8, the guide shaft 36 of the second burr die 32 is inserted through the shaft insertion hole 521d2.

[0023] 《Top mold 11》 An upper mold 11 as a first molding die and a lower mold 12 as a second molding die are a pair of molds that form a product molding cavity space S1 by being stacked together. The upper mold 11 has a central portion that protrudes downward, and a recess corresponding to at least a portion of the product molding cavity space S1 is formed in the protruding portion 11b. An annular opening 11a that defines the opening of the recess is provided at the lower end of the protruding portion 11b. A pointed end portion that protrudes downward is provided on the outer diameter side of the opening 11a. The pointed end portion has an annular tapered surface that increases in diameter toward the top on the outer diameter side of the opening 11a, and a cylindrical surface provided at the outer end of the tapered surface. The upper mold 11 is attached to the recess 51a of the upper holder 51.

[0024] 《Lower mold 12》 The lower mold 12 has a mold surface 12a (see FIG. 6) with a peripheral portion corresponding to the opening 11a of the upper mold 11. By placing the lower mold 12 on the upper mold 11, a product-molding cavity space S1 is formed between the upper mold 11 and the lower mold 12. In this embodiment, almost the entire product-molding cavity space S1, including the undercut portion, is formed by a recess formed on the upper mold 11 side. The lower mold 12 is a substantially cylindrical member, and a mold surface 12a is formed on the upper surface of the lower mold 12. The mold surface 12a may be a flat surface, or may have a recess formed thereon that forms part of the product-molding cavity space S1. The lower mold 12 is attached to an intermediate holder 52, and is arranged so that the mold surface 12a and the opening 11a of the upper mold 11 overlap in the vertical direction. The peripheral portion of this mold surface 12a functions as an inner cutter 12a1 (see FIG. 8). When the upper mold 11 and the lower mold 12 are closed, the peripheral edge of the mold surface 12a and the protrusion 11b are spaced apart with a slight gap in the vertical direction. In this embodiment, such a gap is provided around the entire periphery. Through this gap, the product molding cavity space S1 communicates with the flash cavity space 301 described below. In this embodiment, the first molding die is the upper mold 11 and the second molding die is the lower mold 12, but the first molding die and the second molding die may be configured upside down. The arrangement of the first molding die and the second molding die is not limited to the embodiment unless otherwise specified.

[0025] Lower mold 12 is provided at the upper end of a columnar shaft standing upward from the center of bottom 521d of casing 521, and is disposed within the cylindrical portion of casing 521. That is, mold surface 12a of lower mold 12 is located closer to bottom 521d than the other end of the cylindrical portion of casing 521. In addition, columnar restricting member 523 standing downward from the center of bottom 521d of casing 521 has a protruding portion 523a protruding outward at its lower end.

[0026] "Bali type 30" The flash mold 30 is an annular mold. As shown in Fig. 10, the flash mold 30 is provided around the upper mold 11 and the lower mold 12 when the upper mold 11 and the lower mold 12 are closed, and has a flash cavity space 301 that communicates with the product molding cavity space S1.

[0027] The burr mold 30 is composed of an annular first burr mold 31 and a second burr mold 32, and when the upper mold 11 and the lower mold 12 are closed, the first burr mold 31 and the second burr mold 32 are closed around the upper mold 11 and the lower mold 12. The lower surface of the first burr mold 31 and the upper surface of the second burr mold 32 are provided with recesses 301a and 301b, respectively, which form part of a burr cavity space 301.

[0028] <First Bali Type 31> As shown in FIGS. 7 and 10 , the first burr mold 31 is an annular mold, and a through-hole is formed in the center of the first burr mold 31, into which the protruding portion 11b of the upper mold 11 can fit. The inner peripheral surface of the first burr mold 31 and the outer peripheral surface of the protruding portion 11b are formed to correspond to each other. The lower portion of the inner peripheral surface of the first burr mold 31 is provided with a tapered surface that is inclined corresponding to the tapered surface that forms part of the outer peripheral surface of the protruding portion 11b. The lower portion of the inner peripheral surface of the first burr mold 31 is formed into a pointed shape facing inward by the tapered surface and a horizontal annular lower surface facing the burr cavity space 301. This annular pointed end is located adjacent to the opening of the protruding portion 11b when the protruding portion 11b is fitted into the first burr mold 31. The inner diameter of this pointed end is set to be approximately the same as the outer diameter of the peripheral portion of the die surface 12 a that functions as the inner cutter, for example, 0.1 mm or less, and this pointed end functions as the outer cutter 302 .

[0029] The first burr die 31 has a cylindrical outer peripheral surface, the outer diameter of which is slightly smaller than the inner diameter of the cylindrical portion of the casing 521, and is movable up and down between the shaft on which the lower die 12 is mounted and the cylindrical portion of the casing 521. The first burr die 31 is supported from below by four guide shafts 35 arranged at 90-degree intervals in the circumferential direction. As shown in FIG. 10, each guide shaft 35 penetrates the second burr die 32, and as shown in FIG. 7, each guide shaft 35 is inserted through the shaft insertion holes 521d1 and 53c4, penetrating the bottom portion 521d of the casing 521 and the upper surface portion 53c2 of the frame 53c. A lower base member 37 is attached to the lower end of each guide shaft 35, and the first burr die 31, guide shafts 35, and lower base member 37 are integrated together.

[0030] 7, the lower base member 37 is a disk-shaped member housed in a cylindrical frame 53c so as to be movable up and down. An insertion hole 37a is formed in the center of the lower base member 37. A restricting member 523 attached to the intermediate holder 52 is inserted into the insertion hole 37a. A protruding portion 523a provided at the lower end of the restricting member 523 is configured to be able to engage with the lower base member 37 from below.

[0031] Within the frame 53c, a disk-shaped upper base member 38 is provided above the lower base member 37 and is movable in the vertical direction so as to face the lower base member 37. Each guide shaft 35 passes through the upper base member 38. A first spring 61 is attached to each guide shaft 35. The first spring 61 is a compression coil spring, which is inserted into the guide shaft 35 and attached in a compressed state between the lower base member 37 and the upper base member 38.

[0032] <Second burr type 32> As shown in FIGS. 8 and 10 , the second burr mold 32 is an annular mold facing the first burr mold 31. In this embodiment, the second burr mold 32 is a substantially cylindrical member. A recess 301b is formed in the upper surface of the second burr mold 32, forming part of the burr cavity space 301. A hole 321 is formed in the center of the second burr mold 32, through which a cylindrical shaft on which the lower mold 12 is provided is inserted. The upper opening diameter of the hole 321 is the same as the outer diameter of the peripheral portion of the mold surface 12a, e.g., 0.1 mm or less. The second burr mold 32 has a cylindrical outer peripheral surface, and the outer diameter of the outer peripheral surface is slightly smaller than the inner diameter of the cylindrical portion of the casing 521, similar to the first burr mold 31. The second burr mold 32 is movable vertically between the shaft on which the lower mold is provided and the cylindrical portion of the casing 521. The cylindrical portion of the casing 521 functions as a guide member that guides the second burr die 32 in the up and down direction. The second burr die 32 of the lower die 12 has a shaft insertion hole 322 formed around the hole 321, through which the guide shaft 35 is inserted.

[0033] The second burr die 32 is supported from below by four guide shafts 36 spaced 90 degrees apart in the circumferential direction. Each guide shaft 36 is inserted through a shaft insertion hole 521d2, 53c5, penetrating the bottom 521d of the casing 521 and the upper surface 53c2 of the frame 53c. The lower end of the guide shaft 36 is attached to the upper base member 38, thereby integrating the second burr die 32, guide shaft 36, and upper base member 38. The upper base member 38 also has a notch of the same size as the notch 37c in the lower base member 37, at a position that overlaps with the notch 37c. Four second springs 62 are attached in a compressed state between the upper base member 38 and the spring seat member 53b. Each of the first springs 61 is a compression coil spring. As shown in FIG. 8, the second burr die 32 is pushed upward by the elastic reaction force of the second springs 62.

[0034] In this embodiment, the upper mold 11 is attached to the upper holder 51. The lower mold 12 is attached to the intermediate holder 52. As shown in FIG. 8, the second burr mold 32 is urged upward by the elastic reaction force of the second spring 62 via the upper base member 38 and the guide shaft 36. As shown in FIG. 7, the first burr mold 31 is urged downward by the elastic reaction force of the first spring 61 via the lower base member 37 and the guide shaft 35. Therefore, as shown in FIG. 1, when the upper holder 51 is raised, the elastic reaction forces of the first spring 61 and the second spring 62 apply a pressing force from the first burr mold 31 to the second burr mold 32, closing the first burr mold 31 and the second burr mold 32. At this time, the shaft 41 of the locking member 40 is pre-positioned to position (B) corresponding to the notch 37c of the lower base member 37. When the shaft member 41 is operated to the position (B), the shaft member 41 can fit into the notch 37c, so that the lower base member 37 is in a state where it can move up and down.

[0035] When the upper holder 51 is lowered from the state shown in Fig. 1, the upper die 11 abuts against the first burr die 31 from above, and the protrusion 11b of the upper die 11 fits into the through hole of the first burr die 31. When the upper holder 51 is further lowered, the first burr die 31 and the second burr die 32 are pushed down against the elastic reaction force of the second spring 62, while the fit between the protrusion 11b and the through hole is maintained. When the upper holder 51 is lowered, the shaft 41 of the locking member 40 is previously moved to position (B) corresponding to the notch 37c of the lower base member 37 (see Fig. 4). This allows both the lower base member 37 and the upper base member 38 to move up and down without interfering with the shaft 41.

[0036] As shown in FIGS. 9 and 10 , the upper holder 51 is pushed down to a position where it abuts against the intermediate holder 52. At this time, the upper mold 11 and the lower mold 12 are closed. The first burr mold 31 and the second burr mold 32 are closed around the upper mold 11 and the lower mold 12, so that the product molding cavity space S1 and the burr cavity space 301 are connected to each other. As shown in FIGS. 9 and 10 , the preform 220 is molded in the product molding cavity space S1 formed by the upper mold 11 and the lower mold 12. Furthermore, excess material of the preform 220 that does not fit into the product molding cavity space S1 flows into the burr cavity space 301, forming a burr 202. At this time, the burr 202 formed in the burr cavity space 301 is molded while attached to the molded product 200. It is preferable that the burr cavity space 301 has a sufficient space to absorb excess material, and the preform 220 contains an amount of excess material that can be accommodated in the burr cavity space 301.

[0037] 11 to 14 are cross-sectional views of a mold 10 for molding rubber products. FIG. 11 shows a state in which the upper mold 11 is raised and the molded product 200 is removed from the upper mold 11 after molding the molded product 200 as shown in FIG. 9 . That is, FIG. 11 shows a state in which the upper mold 11 and the lower mold 12 are opened. FIG. 12 shows a state in which the lower mold 12 is raised from the state shown in FIG. 11 and the flash 202 is removed from the molded product 200. FIG. 13 shows a state in which the lower mold 12 is further raised from the state shown in FIG. 12 and the flash mold 30 is opened. FIG. 14 shows a state in which the lower base member 37 is locked in the state shown in FIG. 13 and the intermediate holder 52 is lowered while the flash mold 30 is kept open. In the state shown in FIG. 14 , the flash 202 is removed from the opened flash mold 30 through the gap between the upper holder 51 and the intermediate holder 52. The states shown in each figure are described below.

[0038] After the molded product 200 is molded in the state shown in FIG. 9, the upper holder 51 is raised. In this embodiment, the molded product 200 has an undercut portion. Therefore, when the upper mold 11 begins to rise, the molded product 200 rises while fitting into the recess of the upper mold 11 due to the effect of the undercut portion. Furthermore, with the first and second burr molds 31 and 32 closed, the elastic reaction force of the second spring 62 causes the second and first burr molds 32 and 31 to rise as the upper holder 51 rises. The first and second burr molds 31 and 32 rise to a position where the upper base member 38, to which the second spring 62 is attached, abuts the upper surface portion 53c2 of the frame 53c attached to the lower holder 53. When the upper holder 51 further rises, the upper mold 11 and the first burr mold 31 separate, as shown in FIG. 11. At this time, the flash 202 is held by the first flash mold 31 and the second flash mold 32. As a result, the molded product 200 is pulled downward by the rising upper mold 11, and is removed from the product molding cavity space S1 of the upper mold 11, as shown in FIG.

[0039] Next, the intermediate holder 52 is raised relative to the lower holder 53. When the intermediate holder 52 is raised, the lower mold 12 attached to the intermediate holder 52 is raised. At this time, as shown in FIG. 12 , with the first burr mold 31 and the second burr mold 32 closed, the lower mold 12 passes through the burr cavity space 301 between the first burr mold 31 and the second burr mold 32 and rises. The molded product 200 is pushed up by the lower mold 12 and separated from the burr 202 held by the first burr mold 31 and the second burr mold 32. In this embodiment, an inner cutter 12a1 is formed on the peripheral edge of the mold surface 12a of the lower mold 12. On the other hand, an outer cutter 302 is formed on the pointed end of the first burr mold 31. Therefore, the burr 202 is smoothly separated from the molded product 200 by being sheared by the inner cutter 12a1 and the outer cutter 302.

[0040] 12 shows a state in which the intermediate holder 52 has risen to a height at which the protruding portion 523a at the lower end of the regulating member 523 attached to the intermediate holder 52 engages with the lower base member 37. Up to this height, the second burr die 32 is pushed up by the action of the second spring 62, and the first burr die 31 is pushed down by the action of the first spring 61, so the first burr die 31 and the second burr die 32 are maintained in a closed state.

[0041] When the intermediate holder 52 is raised from the state shown in Fig. 12, the regulating member 523 attached to the intermediate holder 52 rises. Accordingly, as shown in Fig. 13, the lower base member 37 engaged with the protruding portion 523a at the lower end of the regulating member 523 rises. This causes the first burr die 31 to rise relative to the second burr die 32, opening the burr die 30. At this time, because the first burr die 31 and the second burr die 32 are disposed inside the casing 521, it is not possible to access the space between the first burr die 31 and the second burr die 32 from the outside. Therefore, the cut burr 202 cannot be removed.

[0042] In this embodiment, when the intermediate holder 52 is raised, the lower base member 37 is positioned above the shaft member 41. Then, as shown in FIG. 13, the locking member 40 attached to the lower holder 53 is rotated, and the shaft member 41 is moved from a position (B) corresponding to the notch 37c of the lower base member 37 to a position (A) that restricts the lower base member 37 from descending (see FIG. 4). Thereafter, as shown in FIG. 14, the intermediate holder 52 is lowered. As a result, the casing 521 and the restricting member 523 attached to the intermediate holder 52 are lowered, but the lower base member 37 is maintained at the height supported by the shaft member 41.

[0043] 14, the first burr die 31 and the second burr die 32 are in an open state, but the casing 521 is lowered to a position lower than the position at which the first burr die 31 and the second burr die 32 are open. This makes it possible to access the gap S3 between the first burr die 31 and the second burr die 32 from the outside, and the cut burr 202 can be removed through the gap S3 and the gap S4 between the upper holder 51 and the intermediate holder 52. For example, the burr 202 is removed by blowing air from the gap S4 between the upper holder 51 and the intermediate holder 52 into the gap S3 between the first burr die 31 and the second burr die 32.

[0044] In this way, in this rubber product molding mold 10, by operating the locking member 40, the intermediate holder 52 is operated while the first flash mold 31 and the second flash mold 32 are maintained in an open state. Therefore, the rubber product molding mold 10 can be operated in a state in which the flash 202 can be easily removed. This shortens the time required to remove the flash, and can shorten the lead time of the manufacturing process.

[0045] Next, after the flash 202 has been removed, the intermediate holder 52 is raised again, and the lower base member 37 is moved away from the shaft 41 (see FIG. 13). In this state, the locking member 40 is rotated, and the shaft 41 is moved to position (B) retracted from the lower base member 37. After the shaft 41 has been moved to position (B) corresponding to the notch 37c of the lower base member 37, the intermediate holder 52 is lowered. This causes the first flash mold 31 to descend together with the intermediate holder 52. This returns the rubber product molding mold 10 to a state in which the preform 220 can be set, as shown in FIG.

[0046] As described above, with this rubber product molding mold 10, the following steps are repeated in sequence by operating the mold 10: setting the preformed product 220 ( FIG. 1 ), molding the molded product 200 ( FIG. 9 ), demolding the molded product 200 ( FIG. 11 ), cutting off the burrs 202 ( FIG. 12 ), holding the burr mold 30 in an open state ( FIG. 13 ), removing the burr 202 by opening the gap S3 between the first burr mold 31 and the second burr mold 32 to the outside ( FIG. 14 ), releasing the burr mold 30 from the open state ( FIG. 13 ), and setting the preformed product 220 ( FIG. 1 ). This allows molded products 200 to be continuously molded. With this mold 10, the molded product 200 can be molded from the preformed product 220 that has been pre-weighed to minimize the burrs 202, resulting in less material waste.

[0047] Actuator 82 1, the rubber product molding mold 10 may include an actuator 82 for operating the die set 50 and the locking mechanism 400, and a control device 80. The actuator 82 is controlled by the control device 80, whereby the die set 50 and the locking mechanism 400 are operated.

[0048] The actuator 82 may be configured, for example, as a hydraulic drive unit or a servo motor. For example, the upper holder 51 and the intermediate holder 52 may be configured to be driven to move up and down by a hydraulic drive unit. The locking mechanism 400 may be configured to be driven to rotate by a hydraulic drive unit or a servo motor. In the above-described embodiment, it is preferable to include a drive mechanism for driving the upper mold 11, the lower mold 12, and the burr mold 30. As described above, the drive mechanism may be realized by the die set 50 and the guides, springs, locking members, etc. incorporated in the die set 50.

[0049] Control device 80 Each process of the control device 80 can be realized by, for example, a pre-programmed sequence control. The control device 80 may be configured to execute, for example, the following first to fifth processes.

[0050] The first process is a process of opening the first mold and the second mold. For example, in the embodiment shown in Fig. 1, the die set 50 may be operated so that the upper holder 51 is raised. In this process, the upper mold 11 and the lower mold 12 are opened, allowing the preform 220 to be set.

[0051] The second process is a process of closing the first and second molding dies and relatively moving the first and second molding dies and burr dies to a position where the product molding cavity space S1 and the burr cavity space are in communication with each other. For example, in the embodiment shown in FIG. 1, the die set 50 may be operated so that the upper holder 51 is lowered, as shown in FIG. 9. This closes the upper mold 11 and the lower mold 12, and the molded product 200 is molded. In addition, the first burr dies 31 and the second burr dies 32 are positioned adjacent to the upper mold 11 and the lower mold 12 so that the product molding cavity space S1 and the burr cavity space 301 are in communication with each other. This allows excess material to flow into the burr cavity space 301.

[0052] The third process is a process in which the first and second molds are opened after the second process. For example, in the embodiment shown in Fig. 1, the die set 50 may be operated so that the upper holder 51 is raised, as shown in Fig. 11. In this case, the upper mold 11 and the lower mold 12 are opened, and the molded product 200 is removed from the product molding cavity space S1.

[0053] In the fourth process, after the third process, the second molding die and the burr die are moved relative to each other, and the burr formed in the burr cavity space is separated from the product molded in the product cavity space by the inner and outer cutters. In the embodiment shown in Fig. 1, the die set 50 may be operated so that the intermediate holder 52 is raised, as shown in Fig. 12. In this case, the lower die 12 is raised, pushing up the molded product 200 held by the burr die 30, and the burr 202 is cut off by the inner cutter 12a1 provided on the lower die 12 and the outer cutter 302 provided on the burr die 30.

[0054] The fifth process is a process of opening the first burr mold 31 and the second burr mold 32. In the fifth process, it is preferable that the gap S3 between the first burr mold 31 and the second burr mold 32 is opened to the outside while the gap S3 is maintained. This makes it possible to remove the burr 202 from the gap S3 between the first burr mold 31 and the second burr mold 32.

[0055] In the embodiment shown in FIG. 1, after the fourth process, as shown in FIG. 13, the intermediate holder 52 is further elevated. As a result, the protruding portion 523a at the lower end of the regulating member 523 attached to the intermediate holder 52 engages with the lower base member 37, thereby elevating the lower base member 37. This elevates the first burr die 31 relative to the second burr die 32, opening the first burr die 31 and the second burr die 32. Furthermore, the locking mechanism 400 is operated, and the shaft 41 of the locking member 40 restricts the descent of the lower base member 37. In this state, the intermediate holder 52 is lowered. This maintains the gap S3 between the first burr die 31 and the second burr die 32. Further lowering the intermediate holder 52 exposes the gap S3, which was previously covered by the casing 521. This allows the burr 202 to be removed from the gap S3 between the first burr die 31 and the second burr die 32.

[0056] Thereafter, the die set 50 and the locking mechanism 400 are operated to return the rubber product molding mold 10 to the state shown in FIG. 1, in which the preform 220 can be set.

[0057] 1, a set of rubber product molding dies 10 is provided in a die set 50 consisting of a lower holder 53, an intermediate holder 52, and an upper holder 51. However, the present invention is not limited to this configuration, and multiple sets of rubber product molding dies 10 may be incorporated into one die set 50. In this case, multiple molded products 200 can be molded simultaneously by the multiple sets of rubber product molding dies 10 incorporated into one die set 50.

[0058] Although one embodiment of the rubber product molding die 10 has been described above, the rubber product molding die 10 is not limited to this form. For example, the flash die 30 may be an annular die having a flash cavity space 301 that communicates with the product molding cavity space S1 when the upper die 11 as the first molding die and the lower die 12 as the second molding die are closed. The flash die 30 may be configured so that the flash 202 can be removed from the flash cavity space 301, and is not necessarily limited to a die that can be separated into upper and lower parts. The flash die 30 may have a divided structure that is divided, for example, in the radial or circumferential direction.

[0059] In the above-described embodiment, the locking mechanism 400 is provided to keep the first burr die 31 and the second burr die 32 in an open state. However, the locking mechanism 400 is not necessarily required. FIG. 15 is a cross-sectional view showing a rubber product molding die 10A according to another embodiment. The rubber product molding die 10A does not include the locking mechanism 400. Instead, an opening 525 is formed in the side surface of the casing 521 attached to the intermediate holder 52. The opening 525 communicates with the gap S3 between the first burr die 31 and the second burr die 32 when the first burr die 31 and the second burr die 32 are opened. A plurality of such openings 525 may be provided in the circumferential direction of the casing 521. The burr 202 may be removed from the gap S3 between the first burr die 31 and the second burr die 32 through the opening 525.

[0060] Although various explanations have been given above regarding the disclosure herein, the disclosure herein is not limited to the above-described embodiments and modifications unless otherwise specified. Furthermore, the respective configurations of the various described embodiments and modifications can be combined as appropriate as long as they do not interfere with each other. This specification includes the following disclosure. The following disclosure is not limited to the above-described embodiments.

[0061] The present disclosure (1) relates to a mold for molding rubber products. The mold for molding rubber products in this disclosure (1) comprises a first molding die, a second molding die that is placed on top of the first molding die to form a product molding cavity space between the first molding die and the second molding die, and an annular burr mold that is provided around the first molding die and the second molding die and has a burr cavity space that communicates with the product molding cavity space when the first molding die and the second molding die are closed, and an inner blade is provided on the peripheral edge of the second molding die, and an annular outer blade corresponding to the inner blade is provided on a portion of the burr mold that is positioned along the edge on the first molding die side.

[0062] The present disclosure (2) is a mold for molding rubber products described in the present disclosure (1), further comprising: a first drive mechanism that moves the first molding die and the second molding die relatively between a state in which the first molding die and the second molding die are open and a state in which the first molding die and the second molding die are closed; a second drive mechanism that moves the first molding die, the second molding die, and the burr mold relatively to a position where the product molding cavity space and the burr cavity space are connected when the first molding die and the second molding die are closed; and a third drive mechanism that moves the second molding die and the burr mold relatively so that the burr molded in the burr cavity space and the product molded in the product cavity space are separated by the inner blade and the outer blade.

[0063] The present disclosure (3) is a mold for molding rubber products according to the present disclosure (1) or (2), in which the inner blade of the second molding die is configured to pass inside the annular outer blade of the burr mold.

[0064] The present disclosure (4) is a mold for molding rubber products described in any one of the present disclosures (1) to (3), wherein the burr mold has an annular first burr mold and an annular second burr mold, and when the first molding mold and the second molding mold are closed, the first burr mold and the second burr mold are closed around the first molding mold and the second molding mold, and a cavity space for the burr is formed between the first burr mold and the second burr mold. [Explanation of symbols]

[0065] 10,10A Rubber product molding mold 11 Upper mold 12 Lower mold 12a1 inner blade 30 Burr type 302 Outer blade S1 Product molding cavity space

Claims

1. A first molding die; a second mold that is placed on the first mold to form a cavity space for molding a product between the first mold and the second mold; an annular burr mold provided around the first molding die and the second molding die, the burr mold having a cavity space for burrs communicating with the cavity space for product molding when the first molding die and the second molding die are closed; Equipped with An inner blade is provided on the periphery of the second mold, a ring-shaped outer cutter corresponding to the inner cutter is provided at a portion of the burr die that is arranged along the edge of the first molding die, a first drive mechanism that moves the first molding die and the second molding die relatively between a state in which the first molding die and the second molding die are open and a state in which the first molding die and the second molding die are closed; a second drive mechanism that moves the first molding die, the second molding die, and the burr mold relatively to a position where the product molding cavity space and the burr cavity space communicate with each other when the first molding die and the second molding die are closed; a third drive mechanism that moves the second molding die and the burr mold relatively so that the burr molded in the burr cavity space and the product molded in the product molding cavity space are separated by the inner cutter and the outer cutter; and Equipped with Molds for molding rubber products.

2. 2. The mold for molding rubber products according to claim 1, wherein the inner blade of the second molding die is configured to pass inside the annular outer blade of the burr die.

3. A first molding die; a second mold that is placed on the first mold to form a cavity space for molding a product between the first mold and the second mold; an annular burr mold provided around the first molding die and the second molding die, the burr mold having a cavity space for burrs communicating with the cavity space for product molding when the first molding die and the second molding die are closed; Equipped with An inner blade is provided on the periphery of the second mold, a ring-shaped outer cutter corresponding to the inner cutter is provided at a portion of the burr die that is arranged along the edge of the first molding die, A mold for molding rubber products, wherein the inner blade of the second molding die is configured to pass inside the annular outer blade of the burr die.

4. The burr mold is an annular first burr mold; Annular second burr type and and When the first molding die and the second molding die are closed, the first flash mold and the second flash mold are closed around the first molding die and the second molding die, The burr cavity space is formed between the first burr mold and the second burr mold. A mold for molding rubber products according to any one of claims 1 to 3.

5. A first molding die; a second mold that is placed on the first mold to form a cavity space for molding a product between the first mold and the second mold; an annular burr mold provided around the first molding die and the second molding die, the burr mold having a cavity space for burrs communicating with the cavity space for product molding when the first molding die and the second molding die are closed; Equipped with An inner blade is provided on the periphery of the second mold, a ring-shaped outer cutter corresponding to the inner cutter is provided at a portion of the burr die that is arranged along the edge of the first molding die, The burr mold is an annular first burr mold; Annular second burr type and and When the first molding die and the second molding die are closed, the first flash mold and the second flash mold are closed around the first molding die and the second molding die, The burr cavity space is formed between the first burr mold and the second burr mold. Molds for molding rubber products.

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