Method for fixing nested die into die body

Abstract

To provide a method for fixing a nested die into a die body, which is capable of detachably fixing the nested die into the die body from a cavity side without using a tool such as a screwdriver, and of allowing an attachment mark transferred to a molded product to be easily accepted as a design of the molded product without using a cover member.SOLUTION: There is provided a method of fixing a nested die 2, which is a method of detachably fixing the nested die 2 into a die body 1 with a fixing member F. The method is configured such that: a through-hole 21 of the nested die 2 and a mounting hole 11 of the die body 1 are arranged so as to overlap on a same central axis; then, a cylindrical portion 32 of the fixing member F is inserted into the through-hole 21 and the mounting hole 11; then, a rod-shaped member 4 is pushed into a main body member 3, the fixing member F is changed from a first state to a second state to fix the nested die 2 to the die body 1; and the rod-shaped member 4 is further pushed into the main body member 3, the fixing member F is changed from the second state to a third state, and the nested die 2 becomes removable from the die body 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for detachably fixing a nested die to a die body with a fixing member. [Background technology]

[0002] For example, in the case of containers manufactured by molding a resin sheet, it may be desired to change the country of origin or store name that is transferred onto the container while maintaining the shape of the container. In such cases, a part of the molding die related to the country of origin or store name may be made into a nested die, and this can be achieved by replacing the nested die.

[0003] The nested die is usually attached to the molding die by fastening screws from the back side of the cavity to prevent the attachment screws from falling into the cavity and the screw marks from being transferred to the molded product.

[0004] Fig. 8 shows a plan view of an example of a molding die, and Fig. 9 shows an assembled cross-sectional view of the molding die M1 of Fig. 8. In the molding die M1 shown in these figures, a nested die 9 related to the country of origin indication and the store name is replaceably fixed to the mold body 1 in the center of the mold body 1 in a plan view. Two female screw holes 91a, 91b are formed on the back surface of the nested die 9, spaced a predetermined distance apart in the longitudinal direction. Meanwhile, two mounting holes 11a, 11b are formed on the bottom surface of the recess 12 of the mold body 1 at positions corresponding to the female screw holes 91a, 91b, and two communication holes 13a, 13b, which have the same central axis as the mounting holes 11a, 11b and have inner diameters larger than the inner diameters of the mounting holes 11a, 11b, are connected to the back surfaces of the mounting holes 11a, 11b. The nested die 9 was attached to the mold body 1 by inserting screws SC into the communicating holes 13a, 13b from the back side of the mold body 1 and screwing them into the female screw holes 91a, 91b of the nested die 9 attached to the recess 12 of the mold body 1.

[0005] When the mold body M1 is fastened with screws from the rear side in this manner, it is necessary to disassemble the mold body M1 when replacing the nested die 9, which takes a great deal of time and effort.

[0006] Therefore, for example, Patent Documents 1 and 2 propose a technique in which a nested mold is screwed to the mold body from the cavity side and the screw holes are covered with a cover member to prevent the screw marks from being transferred to the molded product. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Utility Model Application Publication No. 5-34897 [Patent Document 2] Japanese Utility Model Application Publication No. 7-5709 Summary of the Invention [Problem to be solved by the invention]

[0008] However, with the above-mentioned proposed technology, after the nested mold is screwed to the mold body, it is necessary to further attach a cover member to the screw-fastening hole, and a simpler method for replacing the nested mold is desired.

[0009] The present invention has been made in view of the above-mentioned conventional problems, and its object is to provide a method for fixing a nested mold to a mold body, which allows the nested mold to be detachably fixed to the mold body from the cavity side without using a tool such as a screwdriver, and which does not require a cover member and in which the attachment marks transferred to the molded product are easily accepted as part of the design of the molded product. [Means for solving the problem]

[0010] A method for fixing a nested die according to one embodiment of the present invention that achieves the above object is a method for detachably fixing a nested die to a die body with a fixing member, the nested die having a through hole penetrating in a detachment direction, the die body having an attachment hole penetrating in the detachment direction, the fixing member having a main body member and a rod-shaped member, the main body member having a flange portion having an insertion hole through which the rod-shaped member is inserted, the flange portion having a maximum diameter larger than an inner diameter of the through hole of the nested die, and a cylindrical portion extending in the axial direction from one axial face side of the flange portion, having a plurality of slits formed at predetermined intervals in the circumferential direction from the tip toward the flange portion, the cylindrical portion being insertable into the through hole and the attachment hole and having a convex portion on an inner surface, the rod-shaped member being insertable into the insertion hole and having an expanded diameter portion in an axial mid portion, the fixing member being configured to switch between a first state in which the rod-shaped member is inserted into the insertion hole of the main body member and the cylindrical portion is insertable into the through hole and the attachment hole, and a second state in which the rod-shaped member is inserted into the insertion hole of the main body member and the cylindrical portion is insertable into the through hole and the attachment hole, a second state in which the rod-shaped member is pushed into the main body member, causing the enlarged diameter portion to come into contact with the convex portion, causing the cylindrical portion to expand radially outward and become unable to pass through the mounting hole; and a third state in which the rod-shaped member is pushed further into the main body member from the second state, causing the enlarged diameter portion to come into contact with the convex portion and become able to pass through the through hole and the mounting hole; after the through hole of the nested mold and the mounting hole of the mold main body are arranged so as to overlap on the same central axis, the cylindrical portion of the fixing member is inserted into the through hole and the mounting hole; then the rod-shaped member is pushed into the main body member, causing the fixing member to change from the first state to the second state, thereby fixing the nested mold to the mold main body; and then the rod-shaped member is pushed further into the main body member, causing the fixing member to change from the second state to the third state, making the nested mold removable from the mold main body.

[0011] In the fixing method having the above configuration, it is preferable that the rod-shaped member has a first recess and a second recess on the axial front and rear sides of the enlarged diameter portion, the depth of which is equal to or greater than the height of the convex portion of the cylindrical portion.

[0012] In the fixing method having the above configuration, it is preferable that the enlarged diameter portion is formed with a circumferential groove capable of engaging with the protrusion.

[0013] In the fixing method having the above configuration, the protrusion may be provided at the tip of the cylindrical portion. [Effects of the Invention]

[0014] According to the method for fixing a nested mold of the present invention, the nested mold can be detachably fixed to the mold body from the cavity side, and the attachment marks transferred to the molded product can be easily accepted as part of the design of the molded product without using a cover member. Furthermore, since a tool such as a screwdriver is not required to attach the nested mold, damage to the mold body by the tool can be suppressed. Furthermore, unlike fixation using screws or the like, there is no risk of the fixation becoming loose due to vibration or the like during actual use. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a process diagram (attachment) showing one embodiment of a fixing method according to the present invention. [Figure 2] 1 is a process diagram (removal) showing one embodiment of a fixing method according to the present invention. [Figure 3] FIG. 1 is a front view of a fixing member that can be used in the present invention. [Figure 4] 4A to 4C are a plan view, a front view, and a bottom view of the main body member of the fixing member of FIG. 3. [Figure 5] FIG. 3(b) is a cross-sectional view taken along line AA in FIG. [Figure 6] 10A to 10C are vertical cross-sectional views showing state changes of the fixing member. [Figure 7] FIG. 10 is a schematic cross-sectional view showing another embodiment of the fixing method according to the present invention. [Figure 8] FIG. 2 is a plan view showing an example of a molding die. [Figure 9] FIG. 9 is an assembled cross-sectional view of the molding die of FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. In the following embodiments, the same or corresponding components will be designated by the same reference numerals, and the description thereof may be omitted as appropriate.

[0017] Figures 1 and 2 show a process diagram illustrating one embodiment of the fixing method according to the present invention. The mold body 1 is the same as that shown in Figures 8 and 9. First, each member will be described below.

[0018] (Nested type) The nesting mold 2 shown in these figures has two recesses 22a, 22b formed on its surface at a predetermined distance in the longitudinal direction. Through-holes 21a, 21b are formed in the centers of the bottom surfaces of the recesses 22a, 22b. In addition, the surface of the nesting mold 2 has recesses or protrusions (not shown, see Figure 8) of desired shapes formed thereon that will become a production area indication, a store name, a pattern, a design, etc. when transferred to a molded product.

[0019] The material of the nesting die 2 is not particularly limited as long as it has a softening temperature higher than that of the molding material such as the resin sheet, and any conventionally known material can be used.

[0020] (Mold body) The surface of mold body 1 is shaped so that the molded product has a desired outer shape. The portion where nesting die 2 is attached is recessed portion 12. Mounting holes 11a and 11b are formed in the bottom surface of recessed portion 12 at positions corresponding to through holes 21a and 21b of nesting die 2, and two communication holes 13a and 13b, which have the same central axis as mounting holes 11a and 11b and have inner diameters larger than those of mounting holes 11a and 11b, are connected to the back surfaces of mounting holes 11a and 11b.

[0021] The material of the mold body 1 is not particularly limited as long as it has a softening temperature higher than that of the molding material such as the resin sheet, and any conventionally known material can be used.

[0022] (fixing member) FIG. 3 is a schematic diagram illustrating one embodiment of the fixing member F. The fixing member F shown in FIG. 3 has a main body member 3 and a rod-shaped member 4, and the rod-shaped member 4 is inserted into an insertion hole 311 (shown in FIGS. 4, 5, etc.) of the main body member 3 to form an integrated member. The materials for the main body member 3 and the rod-shaped member 4 are not particularly limited as long as they have a softening temperature higher than that of a molding material such as a resin sheet, and conventionally known materials can be used. When fixing the nested die 2 to the mold body 1 (described later), a fixing member F in which the main body member 3 and the rod-shaped member 4 are integrated may be used. Alternatively, the main body member 3 and the rod-shaped member 4 may be separated, and the nested die 2 and the mold body 1 may be temporarily fixed together using the main body member 3. The rod-shaped member 4 may then be inserted into the main body member 3 to finally fix the two together.

[0023] (Main body parts) FIG. 4 shows a plan view (FIG. 4(a)), a front view (FIG. 4(b)), and a bottom view (FIG. 4(c)) of the main body member 3, and FIG. 5 shows a cross-sectional view taken along line AA in FIG. 4(a). The main body member 3 shown in these figures has a disk-shaped flange portion 31 having a through-hole 311 at its center, and a tubular portion 32 extending forward from the front surface of the flange portion 31 in the insertion direction. The flange portion 31 and the tubular portion 32 are molded integrally using a resin material or the like. The outer diameter of the flange portion 31 is larger than the inner diameters of the through-holes 21a and 21b of the nesting die 2, and the inner diameter of the through-hole 311 of the flange portion 31 is larger than the outer diameter of the rod-shaped member 4.

[0024] The length of the cylindrical portion 32 in the insertion direction is set to be longer than the sum of the lengths of the through holes 21a, 21b of the nesting die 2 and the mounting holes 11a, 11b of the mold body 1 in the insertion direction. Furthermore, the cylindrical portion 32 has four slits 33 formed at predetermined intervals around the circumferential direction, extending from the front end in the insertion direction toward the base side (flange side). The cylindrical portion 32 is divided into four segments 32a to 32d by the slits 33. Each of the segments 32a to 32d has a claw-shaped protrusion 34 bent radially inward at its front end. Furthermore, the segments 32a to 32d are flexible, and their front end sides can expand and deform radially outward. The outer diameter of the cylindrical portion 32 when not expanded or deformed (normal state) is smaller than the inner diameters of the through holes 21a, 21b of the nested mold 2 and the mounting holes 11a, 11b of the mold body 1, and the cylindrical portion 32 can be inserted through the through holes 21a, 21b and the mounting holes 11a, 11b.

[0025] (rod-shaped member) 3(a), the rod-shaped member 4 has an outer diameter smaller than the inner diameters of the insertion hole 311 of the main body member 3 and the tubular portion 32, and can be inserted in the insertion direction through the insertion hole 311 of the main body member 3. The rod-shaped member 4 has, in order from the front side in the insertion direction, a front end portion 41, a first recessed portion 42, an expanded diameter portion 43, and a second recessed portion 44.

[0026] The front end portion 41 has a conical shape and serves to guide the rod-shaped member 4 so that it is inserted into the insertion hole 311 of the main body member 3.

[0027] The first recess 42 has an inclined surface 421 that is deepest at the connection with the front end 41 and continuously becomes shallower toward the rear in the insertion direction. The depth of the deepest part of the first recess 42 is equal to or greater than the height of the protrusion 34 of the tubular portion 32. The inclined surface 421 of the first recess 42 serves to guide the protrusion 34 of the tubular portion 32 as it moves into the expanded diameter portion 43.

[0028] The expanded diameter portion 43 cooperates with the protrusion 34 of the cylindrical portion 32 to expand the cylindrical portion 32 radially outward, thereby setting the cylindrical portion 32 to a second state in which the cylindrical portion 32 cannot be inserted into the mounting holes 11a, 11b of the mold body 1. A circumferential groove 431 is formed in the expanded diameter portion 43, and the protrusion 34 of the cylindrical portion 32 can be engaged therein. This stably maintains the second state of the fixing member F, which will be described later.

[0029] The second recess 44 has an inclined surface 441 that continuously deepens from the expanded diameter portion 43 toward the rear in the insertion direction, and after reaching its deepest part, has an inclined surface 442 that continuously shallows toward the rear in the insertion direction. The depth of the deepest part of the second recess 44, like the depth of the deepest part of the first recess 42, is set to be equal to or greater than the height of the protrusion 34 of the tubular portion 32.

[0030] (Change in the state of the fixed member) FIG. 6 shows vertical cross-sectional views illustrating changes in state of the fixing member F. The first state of the fixing member F shown in FIG. 6( a) is a state in which the protrusion 34 of the tubular portion 32 of the main body member 3 is engaged with the deepest portion of the first recess 42 of the rod-shaped member 4. The depth of the deepest portion of the first recess 42 is equal to or greater than the height of the protrusion 34 of the tubular portion 32. Therefore, in the normal state, the outer diameter of the tubular portion 32 is smaller than the inner diameters of the through-holes 21 a, 21 b and the mounting holes 11 a, 11 b, and the tubular portion 32 can be inserted through the through-holes 21 a, 21 b and the mounting holes 11 a, 11 b. Note that in the first state, the rod-shaped member 4 can be further inserted into the main body member 3, but the protrusion 34 of the tubular portion 32 cannot normally be pulled out of the main body member 3 because the rear step at the front end of the rod-shaped member 4 obstructs the removal.

[0031] The second state of the fixing member F shown in Figure 6(b) is a state in which the rod-shaped member 4 is further inserted into the main body member 3 from the first state, and the convex portion 34 of the tubular portion 32 of the main body member 3 is engaged with the circumferential groove 431 of the expanded diameter portion 43 of the rod-shaped member 4. When the convex portion 34 of the tubular portion 32 of the main body member 3 engages with the circumferential groove 431 of the expanded diameter portion 43 of the rod-shaped member 4, the tubular portion 32 expands radially outward, and cannot be inserted into the mounting holes 11a, 11b of the mold main body 1. As the rod-shaped member 4 is inserted into the main body member 3, the convex portion 34 of the tubular portion 32 is guided into the circumferential groove 431 by the inclined surface 421 of the rod-shaped member 4, resulting in a smooth state change from the first state to the second state. In the second state, the rear end face of the rod-shaped member 4 and the surface of the flange portion 31 are flush, so force is unlikely to be applied to the rod-shaped member 4 in the insertion direction, and even if some force is applied to the rod-shaped member 4 in the insertion direction, the convex portion 34 of the tubular portion 32 of the main body member 3 is engaged with the circumferential groove 431 of the enlarged diameter portion 43 of the rod-shaped member 4, so the second state is maintained unless a large force is applied that would disengage the engagement.

[0032] 6(c) is a state in which the rod-shaped member 4 is further inserted into the main body member 3 from the second state, and the protrusion 34 of the tubular portion 32 of the main body member 3 engages with the deepest portion of the second recess 44 of the rod-shaped member 4. Similar to the first recess 42, the depth of the deepest portion of the second recess 44 is equal to or greater than the height of the protrusion 34 of the tubular portion 32. Therefore, the outer diameter of the tubular portion 32 returns to its normal state and becomes smaller than the inner diameters of the through holes 21a, 21b and the mounting holes 11a, 11b, allowing the tubular portion 32 to be inserted through the through holes 21a, 21b and the mounting holes 11a, 11b. Note that, to change from the second state to the third state, a relatively large force is required to disengage the protrusion 34 of the tubular portion 32 of the main body member 3 from the circumferential groove 431 of the enlarged diameter portion 43 of the rod-shaped member 4.

[0033] (Method of fixing the nested die to the die body) 1(a), when fixing the nesting die 2 to the mold body 1, first, the nesting die 2 is attached to the recess 12 of the mold body 1. Since the planar shapes of the recess 12 of the mold body 1 and the nesting die 2 are set to be almost identical, attaching the nesting die 2 to the recess 12 of the mold body 1 simultaneously positions the nesting die 2, and the mounting holes 11a and 11b of the mold body 1 and the through holes 21a and 21b of the nesting die 2 are positioned so as to overlap on the same central axis.

[0034] The fixing member F is in a first state in which the protrusion 34 of the tubular portion 32 is positioned in the first recess 42 of the rod-shaped member 4. In the first state, the outer diameter of the tubular portion 32 is smaller than the inner diameters of the through holes 21a, 21b and the mounting holes 11a, 11b, and the tubular portion 32 can be inserted through the through holes 21a, 21b and the mounting holes 11a, 11b. In addition, with the fixing member F in the first state, the rear end of the rod-shaped member 4 protrudes a predetermined length from the surface of the flange portion 31 toward the surface. The protruding length of the rod-shaped member 4 from the flange portion 31 is approximately the same as the axial length from the deepest part of the first recess 42 of the rod-shaped member 4 to the circumferential groove 431 of the expanded diameter portion 43.

[0035] 1(b), the fixing member F is inserted from the front surface side into the through holes 21a, 21b of the nesting die 2 and the mounting holes 11a, 11b of the mold body 1, so that the flange portions 31 of the fixing member F abut against the bottom surfaces of the recesses 22a, 22b of the nesting die 2, and the tip sides of the tubular portions 32 pass through the through holes 21a, 21b and the mounting holes 11a, 11b to be exposed in the communicating holes 13a, 13b. Note that the main body member 3 of the fixing member F may be inserted first into the through holes 21a, 21b and the mounting holes 11a, 11b, and then the rod-shaped member 4 may be inserted into the main body member 3.

[0036] 1(c), the rod-shaped member 4 is pushed in the insertion direction until its rear end surface is flush with the surface of the flange portion 31. This changes the fixing member F from the first state to the second state. In the second state, the expanded diameter portion 43 of the rod-shaped member 4 and the convex portion 34 of the cylindrical portion 32 of the fixing member F come into contact with each other, and the cylindrical portion 32 protruding from the mounting holes 11a and 11b of the mold body 1 to the rear surface side expands radially outward, making it impossible to insert the fixing member 2 into the mounting holes 11a and 11b. This fixes the nested die 2 to the mold body 1 by the fixing member F.

[0037] (How to remove the nested die from the die body) As shown in FIG. 2(d), when removing the nested die 2 from the mold body 1, the rod-shaped member 4 of the fixing member F, which is in the second state and fixes the nested die 2 to the mold body 1, is pushed further in the insertion direction. This causes the fixing member F to change from the second state to the third state. As shown in FIG. 2(e), in the third state, the contact between the expanded diameter portion 43 of the rod-shaped member 4 and the convex portion 34 of the tubular portion 32 of the fixing member F is released, so that the convex portion 34 of the tubular portion 32 is positioned in the second concave portion 44 of the rod-shaped member 4, and the outer diameter of the tubular portion 32 becomes smaller than the inner diameters of the through holes 21a, 21b and the mounting holes 11a, 11b, allowing the tubular portion 32 to be inserted through the through holes 21a, 21b and the mounting holes 11a, 11b.

[0038] 2(f), the fixing member F is pulled out from the nested die 2 in the front direction, the nested die 2 is released from the mold body 1, and the nested die 2 is removed from the mold body 1. Note that the fixing member F and the nested die 2 may be removed from the mold body 1 together.

[0039] (Variation) Fig. 7 shows a modified example of the fixing method according to the present invention. The mold body 5 shown in Fig. 7 is thinner than the previous embodiment, has no through-holes, and only has mounting holes 51. The nested mold 6 is also thinner than the previous embodiment, has no recesses, and only has through-holes 61. When attaching such a nested mold 6 to the mold body 5, it is possible to detachably fix the nested mold 6 to the mold body 5 using the fixing member F used in the previous embodiment. The axial length of the cylindrical portion 32 of the fixing member F is set to be longer than the sum of the axial lengths of the through-hole 61 in the nested mold 6 and the fixing hole 51 in the mold body 5.

[0040] (others) Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Addition, omission, substitution, and other modifications of the configuration are possible within the scope of the spirit of the present invention. The present invention is not limited by the above description, but is limited only by the scope of the appended claims. [Industrial Applicability]

[0041] According to the method for fixing a nested mold of the present invention, the nested mold can be detachably fixed to the mold body from the cavity side, and the attachment marks transferred to the molded product can be easily accepted as part of the design of the molded product without using a cover member. Furthermore, since a tool such as a screwdriver is not required to attach the nested mold, damage to the mold body by the tool can be suppressed. Furthermore, unlike fixation using screws or the like, there is no risk of the fixation becoming loose due to vibration or the like during actual use. [Explanation of symbols]

[0042] 1,5 Mold body 2,6 nested type 3 Main body parts 4 Rod-shaped members F Fixing member 11,51 Mounting hole 21,61 Through hole 31 Flange 311 Insertion hole 32 Cylindrical part 33 Slit 34 Convex part 42 First recess 43 Expanded diameter part 431 Circumferential groove 44 Second recess

Claims

1. A method for removably fixing a nested die to a die body with a fixing member, comprising: the nesting die has a through hole that penetrates in the attachment / detachment direction, The mold body has an attachment hole that penetrates in the attachment / detachment direction, The fixing member has a main body member and a rod-shaped member, The body member includes: a flange portion having an insertion hole, the maximum diameter of which is larger than the inner diameter of the through hole of the nested mold, through which the rod-shaped member is inserted; and a tubular portion having a convex portion on an inner surface thereof, the tubular portion extending in the axial direction from one axial surface side of the flange portion, the tubular portion having a plurality of slits formed at predetermined intervals in the circumferential direction from a tip thereof toward the flange portion, the tubular portion being insertable into the through hole and the mounting hole, the rod-shaped member is insertable into the insertion hole and has an enlarged diameter portion at an intermediate portion in the axial direction; The fixing member is a first state in which the rod-shaped member is inserted into the insertion hole of the main body member and the tubular portion can be inserted into the through hole and the mounting hole; a second state in which the rod-shaped member is pushed into the main body member from the first state, the expanded diameter portion and the convex portion come into contact with each other, and the cylindrical portion expands radially outward, making it impossible to insert the rod-shaped member into the mounting hole; the rod-shaped member is further pushed into the main body member from the second state, the contact between the enlarged diameter portion and the protrusion is released, and the cylindrical portion can be changed to a third state in which the cylindrical portion can be inserted into the through hole and the mounting hole, After the through hole of the insert die and the mounting hole of the mold body are arranged so as to overlap on the same central axis, the cylindrical portion of the fixing member is inserted into the through hole and the mounting hole, Next, the rod-shaped member is pushed into the main body member, the fixing member is changed from the first state to the second state, and the nested die is fixed to the die body; The rod-shaped member is further pushed into the main body member, the fixing member changes from the second state to the third state, and the insert die becomes detachable from the die body. A method for fixing a nested mold to a mold body, comprising:

2. 2. A method for fixing a nested mold according to claim 1, wherein the rod-shaped member has a first recess and a second recess on the axial front and rear sides of the enlarged diameter portion, the first recess and the second recess having a depth equal to or greater than the height of the protrusion of the cylindrical portion.

3. 3. The method for fixing a nested die according to claim 1, wherein the enlarged diameter portion is formed with a circumferential groove capable of engaging the protrusion.

4. 3. The method for fixing a nested mold according to claim 1, wherein the protrusion is provided at the tip of the cylindrical portion.

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