WO2011122057A1

WO2011122057A1 - Molding die

Info

Publication number: WO2011122057A1
Application number: PCT/JP2011/050323
Authority: WO
Inventors: 龍也伊沢
Original assignee: コニカミノルタオプト株式会社
Priority date: 2010-03-31
Filing date: 2011-01-12
Publication date: 2011-10-06
Also published as: JPWO2011122057A1

Abstract

Provided is a molding die wherein, even if a component near a nozzle touch portion of a die is changed, etc., deformation in the die can be easily reproduced, and the need for re-alignment can be reduced. Because a sprue bush (65) comprises an adjustment mechanism (65c), if a component such as a locate ring (66) or a sprue bush (65) is changed for preventing stringing during molding or for cleaning the component, after the alignment and during the use of a molding die (40), correction is possible so that the deformation in the die to which the locate ring (66), the sprue bush (65), or the like, is attached can be reproduced after the change of the component in the same way as before. Thereby, after the exchanged component, etc., is attached, the need for re-alignment of the die can be reduced, and a molded product (MP) can be precisely molded after the component is changed.

Description

Mold

The present invention relates to a molding die used for molding an optical element or the like, and more particularly to a molding die that includes a pair of dies and enables injection molding by forming a mold space by combining both dies.

As a molding die for a resin product, there is a molding die that includes a first die and a second die, and forms a mold space for resin injection between the two dies by combining the two dies (Patent Document 1). reference). The first mold on the fixed side of the molding mold is provided with a sprue bush for injecting resin into the mold space.

JP 2008-221657 A

In a molding die such as Patent Document 1, it is necessary to replace a locating ring, a sprue bushing, or the like constituting the first die in order to prevent stringing during molding or to clean parts.

Depending on the structure, depending on the structure, many parts including the mold and the core mold provided on the mold are disassembled, and the locating ring, sprue bushing, etc. are taken out, cleaned, or replaced with new parts and reassembled. I was doing. After such replacement, etc. (hereinafter referred to as replacement, including disassembly and reassembly), when an optical element is injection-molded, the stress on the mold differs from the previous one due to variations in the replacement part itself and assembly. And unintentional distortion may occur in the mold. As a result, shifts and tilt shifts occur in the product core mold and the hole of the mold, resulting in an influence on the accuracy of the optical element to be molded. Further, if the mold is aligned again after the replacement parts are attached, it takes a lot of labor and time.

Therefore, the present invention can easily reproduce the distortion generated in the mold even if the parts near the nozzle touch part of the mold are replaced, and can reduce the need for realignment. An object of the present invention is to provide a mold that can be formed. Here, reproducing the distortion means making the same state as the state of the distortion generated when the mold is first assembled and aligned. The force that presses the first mold and the second mold is a very large pressure, and some distortion always occurs. The alignment is performed so that the performance of the optical element or the like that molds the distortion is optimal, but this optimal distortion is reproduced.

In order to solve the above-described problems, a molding die according to the present invention includes a first die having a first core die and a second core die, each of which is a product part that forms a die space so as to face each other by closing the die. A molding die comprising a second die, wherein the first die is fixed to a template holding the first core mold, a mounting plate to which the template is attached, and the template or the mounting plate. And a sprue bush for supplying molten resin from the injection molding machine to the mold space and a locating ring fixed to the back side of the mounting plate. The sprue bush has an adjustment mechanism for reproducing the distortion.

In the above mold, the sprue bushing has an adjusting mechanism, so that parts such as locating rings and sprue bushings can be used to prevent stringing and clean parts during molding after the mold has been aligned and in use. Even if the parts are replaced, it is possible to correct the distortion generated in the mold assembled with the locating ring or the sprue bushing so as to be reproduced before and after the parts replacement. Thereby, it is possible to reduce the necessity of aligning the mold again after mounting the replacement part or the like, and it is possible to form a highly accurate molded product even after the part replacement.

In a specific mode or aspect of the present invention, in the molding die, the first die is a stationary die supported by a stationary platen. In this case, the resin injection nozzle of the injection molding machine can be brought into substantially central contact with the sprue bush by using the first mold as a fixed mold and the locate ring.

In another aspect of the present invention, the sprue bush is attached to the inner side of the first sprue bushing that is fitted and fixed to the mold plate or the attachment plate, and is attached to and detached from the injection molding machine side. And a second sprue bushing that is fixedly secured. In this case, by dividing the sprue bush into two parts, the second sprue bush part through which the resin passes can be easily attached and detached from the template.

In yet another aspect of the present invention, the adjustment mechanism is a fastening mechanism by screwing the first sprue bush part and the second sprue bush part. In this case, since the adjustment mechanism is a fastening mechanism by screw tightening, the second sprue bushing portion can be stably fixed to the first sprue bushing portion, and the distortion of the molding die before parts replacement can be easily reproduced. .

In still another aspect of the present invention, the adjustment mechanism is formed on the outer surface of the second sprue bushing and on the mold matching surface side of the second sprue bushing in order to fix the second sprue bushing. It has the fitting part for fastening tools, and the thread groove formed in the inner periphery of a 1st sprue bush part. In this case, the fitting part of the adjustment mechanism can reproduce the distortion caused by the bolt fastening at the time of assembling and the like that is pre-existing on the template or the like by assembling the second sprue bushing with the first sprue bushing with an appropriate force. Moreover, since the fitting part for fastening tools is formed in the mold matching surface side and adjustment can be performed from the mold matching surface side, there exists an advantage which is easy to adjust.

In still another aspect of the present invention, the adjustment mechanism is a fastening mechanism for fixing at least a part of the sprue bushing to the mold plate or the mounting plate, and the fitting for the fastening tool formed on the die mating surface side of the sprue bushing. Has a joint. In this case, it is possible to reproduce and adjust the distortion applied to the template by assembling the sprue bush to the template in a range of appropriate force adjustment by the fitting portion of the adjustment mechanism. Moreover, since the fitting part for fastening tools is formed in the mold matching surface side and adjustment can be performed from the mold matching surface side, there exists an advantage which is easy to adjust.

In yet another aspect of the present invention, the adjustment mechanism has a polygonal recess as a fitting portion. In this case, since the adjustment mechanism has a polygonal recess as the fitting portion, the sprue bush can be assembled while adjusting the screwing force with a fastening tool or the like.

In yet another aspect of the present invention, a hot runner having a heating mechanism between the sprue bushing and the locate ring is further provided. In this case, the hot runner tip mold part can be frequently replaced by the mold configuration having the adjustment mechanism for the thread drawing cleaning and the like that are likely to occur due to the provision of the hot runner. In the molding where it is necessary to always keep the hot runner portion clean, it is possible to mold a molded product that requires highly accurate reproducibility.

It is a conceptual diagram explaining the shaping | molding apparatus incorporating the shaping die of 1st Embodiment. (A) is side sectional drawing explaining a shaping die, (B) is a partial expanded front view of the 1st metallic mold, and (C) is a partial expanded sectional view of the 1st metallic mold. is there. (A) is a figure explaining the flow-path space for supplying resin to mold space, (B) is a figure explaining the mold space for shape | molding a lens. (A) is a perspective view of a four-piece example for explaining the appearance of a molded product formed by the molding die shown in FIG. 1, and (B) is a conceptual side view of a lens as a product. It is a partial expanded sectional view of the 1st metallic mold among the metallic molds concerning a 2nd embodiment. (A), (B) is a figure which shows the modification of a 1st metal mold | die among the metal mold | die which concerns on 1st Embodiment.

[First Embodiment]
Hereinafter, the molding die which is 1st Embodiment of this invention is demonstrated, referring drawings.

As shown in FIG. 1, the molding apparatus 100 includes an injection molding machine 10 that is a main body part that performs injection molding to produce a molded product MP, and a take-out device 20 that is an attached part that takes out the molded product MP from the injection molding machine 10. And a control device 30 that comprehensively controls the operation of each part constituting the molding apparatus 100.

The injection molding machine 10 is a horizontal molding machine and includes a molding die 40, a fixed platen 11, a movable platen 12, a mold clamping plate 13, an opening / closing drive device 15, and an injection device 16. The injection molding machine 10 clamps both

molds

41 and 42 by sandwiching a first mold 41 and a second mold 42 constituting the molding mold 40 between the fixed platen 11 and the movable platen 12. This enables molding.

The fixed platen 11 is fixed to the approximate center of the support frame 14 so as to face the movable platen 12, and supports the take-out device 20 on the upper part thereof. The inner side 11a of the fixed platen 11 faces the inner side 12a of the movable platen 12, and supports the first mold 41 in a detachable manner. The fixed platen 11 is formed with a locating ring hole 11b which is an opening for fitting a locating ring 66 (see FIG. 2) described later.

Between the fixed platen 11 and the first mold 41, a heat insulating plate 52 with a hot runner cord groove is sandwiched. The hot runner cord grooved heat insulating plate 52 is used as a heat flow blocking layer between the stationary platen 11 and the first mold 41. Note that the fixed platen 11 is fixed to the mold clamping plate 13 via a tie bar so that it can withstand the pressure of mold clamping during molding.

The movable platen 12 is supported by a linear guide 15a so as to be movable back and forth with respect to the fixed platen 11. The inner side 12a of the movable platen 12 faces the inner side 11a of the fixed platen 11, and supports the second mold 42 in a detachable manner. A heat insulating plate 53 is sandwiched between the movable platen 12 and the second mold 42. The heat insulating plate 53 is used as a heat flow blocking layer between the movable platen 12 and the second mold 42. In addition, an ejector 45 is incorporated in the movable platen 12. The ejector 45 pushes the molded product MP in the second mold 42 to the first mold 41 side in order to release the molded product MP.

The mold clamping machine 13 is fixed to the end of the support frame 14. The mold clamping machine 13 supports the movable board 12 from the back via the power transmission part 15d of the opening / closing drive device 15 at the time of mold clamping.

The opening / closing drive device 15 includes a linear guide 15a, a power transmission unit 15d, and an actuator 15e. The linear guide 15 a supports the movable platen 12 and enables the movable platen 12 to smoothly reciprocate with respect to the advancing and retreating direction with respect to the fixed platen 11. The power transmission unit 15 d expands and contracts by receiving a driving force from an actuator 15 e that operates under the control of the control device 30. As a result, the movable platen 12 approaches or separates from the mold clamping plate 13 and freely moves forward and backward. As a result, the fixed platen 11 and the movable platen 12 can be brought close to or separated from each other, and the first mold 41 and the second mold 42 can be clamped or opened.

The injection device 16 includes a cylinder 16a, a raw material storage unit 16b, a screw drive unit 16c, and the like. The injection device 16 operates at an appropriate timing under the control of the control device 30, and can inject molten resin from the resin injection nozzle 16d in a temperature-controlled state. In the state where the first mold 41 and the second mold 42 are clamped, the injection device 16 brings the resin injection nozzle 16d into contact with a sprue bushing 65 which will be described later, and the inside of the cylinder 16a with respect to the flow path space FC which will be described later. The molten resin can be supplied at a desired timing and pressure.

A mold temperature controller 46 attached to the injection molding machine 10 circulates a temperature-controlled heat medium in both

molds

41, 42. Thereby, the temperature of both metal mold | dies 41 and 42 can be kept at an appropriate temperature at the time of shaping | molding.

The take-out device 20 includes a hand 21 that can hold the molded product MP and a three-dimensional drive device 22 that moves the hand 21 three-dimensionally. The take-out device 20 operates at an appropriate timing under the control of the control device 30, and remains in the second die 42 after the first die 41 and the second die 42 are separated and opened. It has the role of gripping the molded product MP and carrying it out.

The control device 30 includes an opening / closing control unit 31, an injection device control unit 32, an ejector control unit 33, and a take-out device control unit 34. The opening / closing control unit 31 causes the

molds

41 and 42 to be clamped and opened by operating the actuator 15e. The injection device control unit 32 causes the resin to be injected at a desired pressure into the mold space formed between the

molds

41 and 42 by operating the screw driving unit 16c and the like. The ejector control unit 33 operates the ejector 45 to push the molded product MP remaining in the second mold 42 when the mold is opened from the second mold 42 to release the mold. The take-out device controller 34 operates the take-out device 20 to grip the molded product MP remaining in the second mold 42 after mold opening and mold release and carry it out of the injection molding machine 10.

Hereinafter, the molding die 40 will be described in detail. As shown in FIG. 2A, the second mold 42 of the molding dies 40 can reciprocate in the AB direction. This second mold 42 is moved toward the first mold 41, and both

molds

41, 42 are mold-matched with mold-matching surfaces, that is, parting surfaces PS1, PS2, and clamped. ), A mold space CV for molding a lens and a flow path space FC for supplying resin to the mold space CV are formed.

3 (A), the flow path space FC is a space that forms the sprue portion SP and the runner portion RP of the molded product MP shown in FIG. 4 (A). The flow path space FC is branched into four corresponding to the four runner portions RP. The flow path space FC communicates with each of the four mold spaces CV via the gate portion GS that forms the gate portion GP of the molded product MP at the four branched ends.

3B, the mold space CV is surrounded by a main body space CV1 sandwiched between the first and second transfer surfaces S1 and S2, and the third and fourth transfer surfaces S3 and S4. Flange space CV2. Here, the first and second transfer surfaces S1 and S2 are for forming the optical surfaces OS1 and OS2 of the central optical function part OP in the lens LP shown in an enlarged view in FIG. This corresponds to the end faces of the

product core molds

62 and 72.

On the other hand, the third and fourth transfer surfaces S3 and S4 are portions for forming the flange portion FL of the lens LP, and correspond to the end surfaces of the

template plates

61 and 71. A lens LP shown in FIG. 4B is an objective lens for optical pickup, for example, and corresponds to standards such as DVD and BD.

Returning to FIG. 2A, the first mold 41 includes

mold plates

61 and 63 as peripheral portions on the fixed side, and a locating ring 66 in a mounting plate 64 that supports the nozzle adapter 83 and the like from the back. . More specifically, the first mold 41 includes a plurality of product core molds 62 (first core molds) as product core parts on the fixed side, and a sprue portion SP and a runner portion of the molded product MP shown in FIG. A sprue bushing 65 that forms part of the RP, a locate ring 66 that aligns and fixes the first mold 41 to the stationary platen 11, and a hot that is held in the insertion hole 63a of the template 63 and is connected to the sprue bushing 65. And a runner 81.

The mold 61 of the first mold 41 includes a plurality of core holes 61a for inserting a plurality of product core dies 62, a sprue bushing hole 61b for inserting a sprue bushing 65, and a runner of the molded product MP shown in FIG. A runner recess 61c for forming the part RP, a gate surface 61d for forming the gate part GP, and a lens recess 61e for forming the optical function part of the lens LP are provided. A product core mold 62 is inserted into each core hole 61a, and the front end surface of the product core mold 62 corresponds to the lens recess 61e.

In the template 61, a temperature control circuit hole 61f for circulating a heat medium is formed in order to keep the temperature of the mold at an appropriate temperature during molding. Further, a temperature sensor 61g for measuring the temperature of the first mold 41, that is, the temperature of the mold forming the mold space CV (see FIG. 3) and the temperature in the vicinity thereof is embedded in the mold plate 61.

The sprue bushing 65 is inserted into the sprue bushing hole 61b from behind the template 61 and fixed. A flow path CA1 is formed in the sprue bush 65, and corresponds to a space forming the sprue portion SP of the molded product MP shown in FIG. 4 in the flow path space FC of FIG. .

The sprue bushing 65 has a first sprue bushing portion 65a and a second sprue bushing portion 65b. The first sprue bushing portion 65a and the second sprue bushing portion 65b function as an adjustment mechanism 65c that reproduces the distortion of the mold by a part of each of them cooperating. The adjustment mechanism 65c is a fastening mechanism that uses screw fastening between the first sprue bushing portion 65a and the second sprue bushing portion 65b. The distortion between the

template plates

61 and 63 and the mounting plate 64 is adjusted by the screwing force of the adjusting mechanism 65c, that is, the tightening force of the second sprue bushing portion 65b with respect to the first sprue bushing portion 65a, and at the time of alignment before component replacement The strain state of the mold can be reproduced.

That is, after the alignment of each product core mold in the

molds

41 and 42 and during use, after replacing the parts such as the second sprue bushing 65b in order to prevent stringing and cleaning, the replacement parts By adjusting the axis AX direction (verticality) using the adjusting mechanism 65c against the strain change of the

mold plates

61, 63 and the mounting plate 64 due to the nozzle touch pressure and the clamping force pressure caused by the difference in size and incorporation, the mold is adjusted. Deviation distribution such as distortion in the mounting plate 64 from the plate 61 can be adjusted. Further, since the product core mold is installed away from the axis AX, it is tilted by clamping, and the tilt can be reproduced by the adjusting mechanism.

As shown in FIGS. 2 (B) and 2 (C), the first sprue bushing 65a of the sprue bushing 65 is sandwiched between the divided

template plates

61 and 63 or inserted from behind the template plate 61 and is not shown. It is fixed in a state of being fitted into the sprue bushing hole 61b with a bolt or the like. The first sprue bushing 65a has a cylindrical shape, and a thread groove 65d is formed on the inner periphery of the shaft hole 65g formed in the shaft center. The thread groove 65d constitutes a part of the adjustment mechanism 65c, and is screwed into a thread 65e of a second sprue bush portion 65b described later. Note that a part of the runner recess 61c extending to the template 61 is formed in the first sprue bushing 65a (see FIG. 2B).

The second sprue bushing 65b is attached and fixed in a shaft hole 65g formed in the first sprue bushing 65a. The second sprue bushing 65b is attached and detached from the mounting plate 64 side of the template 61. The second sprue bushing 65b has a cylindrical shape, and a thread 65e is formed on the outer periphery thereof, and a fitting part 65f is formed on the parting surface PS1 side. The screw thread 65e and the fitting portion 65f constitute a part of the adjustment mechanism 65c. The thread 65e is a part that is screwed into a thread groove 65d formed in the first sprue bushing 65a, and the second sprue bushing 65b is screwed into the first sprue bushing 65a to be securely fixed in the shaft hole 65g.

The fitting portion 65f is a portion into which a fastening tool (not shown) used when screwing the second sprue bushing portion 65b into the first sprue bushing portion 65a is fitted. The fitting portion 65f is a polygonal concave portion, and has a paired shape with the tip shape of the fastening tool. Specifically, as shown in FIG. 2B, the shape of the fitting portion 65f is a hexagonal recess, and a hexagon wrench, for example, is used as a fastening tool.

The second sprue bushing 65b can set the pressing force from the parting surface PS1 to the tip of the hot runner 81 quantitatively with a fastening tool after replacement, etc. (Distribution difference due to deviation of the pressure angle of the part) can be reproduced and adjusted.

The second sprue bushing portion 65b is separable from the first sprue bushing portion 65a, and can be appropriately replaced for the purpose of cleaning the yarn drawing prevention component during molding and the component.

As shown in FIG. 2A, the locating ring 66 is an annular part that is detachably fixed to the first mold 41, and is fitted into the locating ring hole 11b of the stationary platen 11 shown in FIG. To do. The locating ring 66 positions the central portion of the first mold 41 and the central portion of the stationary platen 11. The locate ring 66 is fastened and fixed to the mounting plate 64 from behind. By removing the locating ring 66 from the mounting plate 64, the hot runner 81, the nozzle adapter 83, the second sprue bushing 65b, etc., which are mold parts, can be exchanged.

As shown in FIG. 2A, the hot runner 81 is inserted and held in the insertion hole 63a of the template 63 and the insertion hole 64a of the mounting plate 64. The hot runner 81 is supported from the rear by the locating ring 66 together with the nozzle adapter 83, and is prevented from moving in the axis AX direction. Note that this supporting force also contributes to the distortion to be reproduced from the template 61 to the mounting plate 64. As shown in FIG. 2A, the nozzle adapter 83 is held in the locate ring 66, and the hot runner 81 is indirectly supported by the locate ring 66 via the nozzle adapter 83.

The hot runner 81 and the nozzle adapter 83 are provided with

flow paths

81a and 83a for circulating resin. Inside the hot runner 81 and the nozzle adapter 83,

heaters

81b and 83b for keeping the resin in the

flow paths

81a and 83a in a molten state are provided.

The hot runner 81 is connected to a hot runner control unit 82 that controls temperature adjustment of the hot runner 81 and the nozzle adapter 83 through a connector (not shown) through a heat runner 52 with a hot runner cord groove specially provided with a wiring groove. Has been.

It should be noted that the hot runner 81 can be used by exchanging various types of tip structures according to the stringing condition or the like. At this time, the second sprue bushing 65b is also replaced with one adapted to the tip structure of the hot runner 81 to be replaced. When the hot runner 81 is not used, a sprue bush extended to a portion where the resin injection nozzle of the injection molding machine can be touched may be used instead.

As shown in FIG. 2A, the second mold 42 supports a mold plate 71 as a movable peripheral portion, a receiving plate 73 that supports the template 71 from the back, and supports the receiving plate 73 from the back. And an attachment plate 74. More specifically, the second mold 42 includes a plurality of product core molds 72 (second core molds) as core parts on the movable side, and a movable pin (not shown) that protrudes from the product core mold 72 and enables release. A movable pin (not shown) that protrudes and releases the runner portion RP of the molded product MP, and an advance / retreat mechanism 77 that moves the movable pins forward and backward are provided.

The template 71 of the second mold 42 includes a plurality of core holes 71a into which a plurality of product core dies 72 are inserted, and a cold slag recess 71b corresponding to the cold slag part OO of the molded product MP in FIG. , A runner recess 71c for forming the runner portion RP, a gate recess 71d for forming the gate portion GP, and a lens recess 71e for forming the optical function portion of the lens LP. Although illustration is omitted, pin holes for inserting movable pins extend in the cold slug recess 71b and the runner recess 71c. A product core mold 72 is inserted into each core hole 71a, and the front end surface of the product core mold 72 corresponds to the lens recess 71e.

In the template 71, a temperature control circuit hole 71f through which a heat medium flows is formed in order to keep the temperature of the mold at an appropriate temperature during molding. Further, a temperature sensor 71g for measuring the temperature of the second mold 42, that is, the temperature of the mold forming the mold space CV and the temperature in the vicinity thereof is embedded in the mold plate 71.

Hereinafter, manufacturing of a lens using the injection molding machine 10 of FIG. 1 will be described. First, the mold temperature controller 46 heats both

molds

41 and 42 to a temperature suitable for molding. Next, the opening / closing drive device 15 is operated to advance the movable platen 12 to start mold closing. Even when the movable platen 12 moves to the fixed platen 11 side to the die contact position where the first die 41 and the second die 42 come into contact with each other, the closing operation of the opening / closing drive device 15 is further continued. Thereby, the mold clamping which clamps the 1st metal mold | die 41 and the 2nd metal mold | die 42 with required pressure is performed.

Next, the injection device 16 is operated to inject the molten resin into the mold space CV between the clamped first mold 41 and the second mold 42 with a necessary pressure. At this time, the mold space CV and the flow path space FC (see FIG. 3A) are appropriately heated by the mold temperature controller 46, and the resin injection nozzle 16d portion of the injection device 16 is touched by the nozzle. The molten resin supplied from is slowly cooled. The misalignment of the nozzle touch also contributes to the distortion to be reproduced.

When the molten resin is cooled and hardened sufficiently, the opening / closing drive device 15 is operated to open the movable platen 12 backward. Along with this, the second mold 42 moves backward, and the first mold 41 and the second mold 42 are separated from each other. As a result, the molded product MP, that is, the lens LP can be taken out between the two

molds

41 and 42. Thereafter, the molded product MP is carried out by the take-out device 20.

Hereinafter, a method for exchanging parts from the sprue bushing 65 to the locate ring 66 will be described.

First, the second sprue bushing 65b, the hot runner 81, and the nozzle adapter 83, which are parts to be replaced or cleaned, are removed from the first mold 41. First, the connector connected to the wiring extending from the hot runner 81 and provided outside the first mold 41 is removed. Next, the screw of the second sprue bushing 65b of the sprue bushing 65 is slightly loosened. Specifically, the screw of the second sprue bushing portion 65b is rotated from the parting surface PS1 side in the direction of loosening using the fastening tool. The loosening direction is a direction in which the second sprue bushing portion 65 b is separated from the hot runner 81.

Next, the locating ring 66 is removed from the mounting plate 64. Next, the nozzle adapter 83 is removed from the hot runner 81. Next, the hot runner 81 is pulled out from the insertion hole 64 a of the mounting plate 64 and the insertion hole 63 a of the template 63. Thereafter, the second sprue bushing 65b is removed from the first sprue bushing 65a by turning a screw, and is removed via the insertion hole 64a of the mounting plate 64 and the insertion hole 63a of the template 63. The second sprue bushing 65b can be taken out, for example, by attracting a magnet to the second sprue bushing 65b.

Next, an operation of assembling the second sprue bushing 65b, the hot runner 81, and the nozzle adapter 83, which are parts to be replaced or parts after cleaning, into the first mold 41 is performed. First, the second sprue bushing 65b is screwed deeply into the first sprue bushing 65a through the insertion hole 64a of the mounting plate 64 and the insertion hole 63a of the template 63. Next, the hot runner 81 is inserted into the insertion hole 64a of the mounting plate 64 and the insertion hole 63a of the template 63, and the front end of the hot runner 81 is brought into contact with the rear end of the second sprue bushing portion 65b.

Next, the nozzle adapter 83 is attached to the hot runner 81. Next, the locating ring 66 is attached to the attachment plate 64 so as to wrap the nozzle adapter 83, and the hot runner 81 is fixed. Finally, the second sprue bushing 65b is tightened from the parting surface PS1 with a predetermined screwing force. At this time, it is possible to reproduce the displacement of the touch position by placing the shim in a desired direction while keeping the nozzle in contact.

After incorporating the replacement part, the cause of displacement is estimated from the performance of the lens LP, which is the molded product MP, and the fastening force by the second sprue bushing 65b is adjusted in a direction in which the influential factor is eliminated.

The molding die according to the first embodiment has been described above. However, the molding die 40 according to this embodiment needs to be replaced only for parts that need cleaning and replacement, and parts such as a product core mold need to be disassembled. Therefore, it is possible to reduce the necessity of aligning the mold again after mounting replacement parts or the like.

More specifically, in the multi-cavity injection molding like the lens LP shown in FIG. 4B, the molding transfer lens surfaces are precisely measured in μm units in order to ensure the accuracy of each of the

product core molds

62, 72, etc. Need to be aligned. In addition, the resin used for molding is expensive, and a hot runner 81 is incorporated in the mold example shown in FIG. In the above, stringing is likely to occur when the sprue portion SP of the molded product MP is pulled out of the sprue bushing 65 of the first mold 41 due to the incorporation of the hot runner 81.

Therefore, there is a possibility that the thread drawing resin may be sandwiched between the first and

second molds

41 and 42 in the mold closing that requires positioning in units of μm. In this case, the performance of the lens LP will be out of order. Moreover, since the hot runner 81 is likely to generate carbonized foreign matters, there is a possibility that foreign matters may be mixed into the lens LP. Therefore, it is necessary to periodically clean or replace the sprue bushing 65, the hot runner 81, and the like.

At this time, if the first mold 41 is lowered, the mold plate 61 and the like are removed, and the sprue bushing 65 and the hot runner 81 are exchanged, the displacement amount of the first and

second molds

41 and 42 due to the attachment after the exchange. Is not reproduced, and realignment is required due to various factors such as changes in nozzle touch pressure and mold clamping force distribution.

Therefore, as in the present invention, the nozzle touch is adjusted by adjusting the fastening force of the second sprue bushing 65b after replacing or cleaning the parts such as the second sprue bushing 65b and the hot runner 81 without lowering the first die 41. Correction is made so that the distortion in the axis AX direction of the first mold 41 due to changes in pressure, mold clamping force distribution, etc. is reproduced before and after component replacement. In addition, since the direction of tilt direction correction of the product core mold in the entire first mold 41 is narrowed by tightening the adjusting mechanism 65c, the number of steps required for reproduction can be reduced.

From the above, it is possible to reduce the need for realignment in the first mold 41 after replacement of the yarn drawing countermeasure parts of the first mold 41 and the like. In addition, the resin pressure applied to the lens LP at the time of molding due to the effect of the hot runner 81 can be stabilized and the accuracy and quality of the mass-produced product can be stabilized while omitting the trouble of realignment after such component replacement. In addition, since the mold configuration allows easy replacement of parts, it is easy to prevent thread drawing, and the cooling time is shortened due to runner thinning due to the effect of the hot runner 81, thereby shortening the injection molding cycle. , Can reduce the production cost. Furthermore, by easily exchanging parts and having a product performance reproduction mechanism, it is possible to efficiently produce a prototype of a lens using various resins whose threading state changes.

Further, by dividing the sprue bushing 65 into two parts, a first sprue bushing part 65a and a second sprue bushing part 65b, the second sprue bushing part 65b through which the resin passes can be easily attached and detached from the template 61. Can do.

[Second Embodiment]
Hereinafter, the molding die according to the second embodiment will be described. The molding die according to the second embodiment is a modification of the first embodiment, and parts that are not particularly described are the same as those of the first embodiment.

As shown in FIG. 5, in the second embodiment, the sprue bushing 165 is not divided into two like the sprue bushing 65 of the first embodiment, but is a single component. The sprue bushing 165 is detachably fixed from the template 61 side. Specifically, the sprue bushing 165 has a fitting portion 65f formed on the parting surface PS1 side, and can be fastened or separated from the template 61 by a fastening tool (not shown) on the parting surface PS1 side.

Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments, and various modifications are possible. For example, the shape of the mold space CV provided in the injection mold composed of the first mold 41 and the second mold 42 is not limited to the illustrated shape, and can be various shapes. That is, the shape of the mold space CV formed by the

product core molds

62, 72 and the like is merely an example, and can be appropriately changed according to the use of the lens LP. Further, the first transfer surface S1 or the like may or may not be provided with an uneven shape.

Moreover, in the said embodiment, the shape of the fitting part 65f of the adjustment mechanism 65c is an illustration, and should just be a shape which can engage | insert the front-end | tip of a fastening tool. For example, as shown in the modified examples of FIGS. 6A and 6B, a cross-shaped fitting portion 265f that does not interfere with the flow path CA1 may be used. N may be an N-gon.

DESCRIPTION OF SYMBOLS 10 Injection molding machine 11 Fixed platen 12 Movable platen 15 Opening / closing drive device 16 Injection device 20 Taking out device 30 Control device 40 Molding die 41 1st die 42 2nd die 45

Ejector

61, 63, 71

Template

62, 72 Product Core type 73

Receiving plate

64, 74

Mounting plate

65, 165 Sprue bushing 65a First sprue bushing part 65b Second sprue bushing part 65c Adjustment mechanism 66 Locate ring 81 Hot runner 100 Molding device CV type space MP Molded product LP Lens PS1, PS2 Parting surface 52 Insulation plate with hot runner cord groove

Claims

A molding die comprising a first mold and a second mold each having a first core mold and a second core mold that form a mold space opposite to each other by mold closing,
The first mold is
A template holding the first core mold;
A mounting plate to which the template is attached;
A sprue bush that is fixed in the mold plate or the mounting plate and supplies molten resin from an injection molding machine to the mold space;
A locating ring fixed to the back side of the mounting plate;
Have
The sprue bush has an adjustment mechanism that reproduces strain, and a molding die.
The molding die according to claim 1, wherein the first die is a fixed die supported by a fixed platen.
The sprue bush is attached to the inner side of the first sprue bushing and the cylindrical first sprue bushing fitted and fixed to the template or the mounting plate, and is detachably fixed from the injection molding machine side. The molding die according to claim 1, further comprising a second sprue bush portion.
4. The molding die according to claim 3, wherein the adjusting mechanism is a fastening mechanism by screwing the first sprue bush part and the second sprue bush part.
The adjusting mechanism includes a screw thread formed on an outer periphery of the second sprue bush part and a fitting for a fastening tool formed on a mold matching surface side of the second sprue bush part in order to fix the second sprue bush part. The molding die according to claim 4, further comprising a joint portion and a thread groove formed on an inner periphery of the first sprue bush portion.
The adjustment mechanism is a fastening mechanism for fixing at least a part of the sprue bushing to the mold plate or the mounting plate, and has a fitting part for a fastening tool formed on the mold matching surface side of the sprue bushing. The molding die according to claim 1 or 2, characterized by the above.
The molding die according to claim 5 or 6, wherein the adjustment mechanism has a polygonal concave portion as the fitting portion.
The molding die according to any one of claims 1 to 7, further comprising a hot runner having a heating mechanism between the sprue bushing and the locating ring.