WO2016175108A1

WO2016175108A1 - Optical product molding apparatus and manufacturing method

Info

Publication number: WO2016175108A1
Application number: PCT/JP2016/062575
Authority: WO
Inventors: 田村義文; 高木信; 澤登大介; 谷川裕海; 高橋洋昭; 佐藤望; 荒樋悟郎; 阿部良幸
Original assignee: コニカミノルタ株式会社
Priority date: 2015-04-30
Filing date: 2016-04-20
Publication date: 2016-11-03
Also published as: JPWO2016175108A1; CN107530930A

Abstract

Provided are an optical product molding apparatus, etc. with which deformation of an optical transfer surface can be prevented while preventing burr formation. The molding apparatus 100 is provided with a molding die 40 comprising sliding cores 72, contact pressure sensors 54 for measuring the contact pressure of the contact surfaces 72p of the sliding cores 72, position adjustment units 59 for adjusting the positions of the sliding cores 72, and a position adjustment control unit 33. Since the position adjustment units 59 secure the gap GA between the sliding cores 72 at the beginning of resin injection in the molding step, it is possible to force out air remaining inside the cavity CV. Moreover, since the sliding cores 72 are brought into contact with each other by the position adjustment units 59 prior to completion of resin injection on the basis of the output of the contact pressure sensors 54, it is possible to keep contact pressure from becoming excessive due to butting of the sliding cores 72 and the inside surfaces 72a, which are optical transfer surfaces, from being deformed.

Description

Optical product molding apparatus and manufacturing method

The present invention relates to an optical product molding apparatus and manufacturing method that enable high-precision molding, and more particularly to an optical product molding apparatus and manufacturing method including a mold having a slide core movable in a mold.

As a device to improve the surface accuracy of optical transfer surfaces such as polygon mirrors, a resin mold with a nesting and drive mechanism that can apply compressive force to the resin from the inside of the mold part for forming the reflecting mirror surface with the injected resin A mold is disclosed (Patent Document 1).

Further, a method for manufacturing a polygon mirror having a chamfered portion at a ridge line position or the like is disclosed (Patent Document 2). In this manufacturing method, the fluidity of the ridge line portion can be improved by providing a chamfered portion and reducing the pressure immediately before the resin filling is completed, or stress is concentrated on the chamfered end to improve the surface accuracy. .

A resin molding mold having a structure in which a split core for each reflecting mirror surface is provided between the upper and lower molds by improving the two divisions of the upper and lower molds of the conventional mold is disclosed (Patent Document 3). In this mold, the resin on the mirror surface portion can be compressed with an equal amount of compression by the slide core, so that variations in internal distortion of the polygon mirror can be prevented.

The molds of Patent Documents 1 and 3 are molds of a type in which a slide core or a nest is brought into contact with each other between upper and lower molds to press the resin from the lateral direction, but optical transfer formed on the slide core or the like by pressurization. The surface is deformed such as warping or bending, and the optical surface of the optical product is deteriorated due to the deformation of the optical transfer surface. On the other hand, if the pressure is insufficient, the resin enters the gaps such as the slide core, and burrs are formed, which causes poor appearance.

Describing this point in more detail, when using a slide core, it can be said that it is desirable to ensure a gap without strongly abutting the slide core so that the optical surface of the optical molded product is not warped. However, in optical products that require high accuracy, particularly small optical products, it is necessary to increase the fluidity and filling pressure of the resin to achieve high transferability. Techniques to achieve high transferability include heat cycle method, gas assist molding method, adiabatic molding method, ingenuity of injection conditions, etc., but it does not enter in normal molding by increasing the fluidity and filling pressure of resin In some cases, resin enters the gaps between the slide cores, resulting in poor appearance due to the generation of burrs. Due to the occurrence of such burrs, there is also a problem that quality variations are likely to occur for each molding shot. In fact, if an attempt is made to improve the transferability of the optical surface by increasing the resin fluidity, the resin enters the gap between the slide cores of about 5 μm, and burrs are generated. Thus, in a molding apparatus using a slide core, it is not easy to prevent the formation of burrs in the gap around the slide core while preventing deterioration of the optical surface of the optical product. It can be said that burrs tend to be formed near the optical surface.

On the other hand, the mold of Patent Document 2 is not related to a mold in which a plurality of slide cores are brought into contact with each other to form an optical transfer surface, and it is not easy to form an optical surface such as a polygon mirror with high accuracy. . In particular, when an optical product such as a polygon mirror has a reflective surface perpendicular to the rotation axis or an overhanging reflective surface, the reflective surface may not be formed.

On the other hand, as a resin molding method using a sensor and an actuator, the displacement amount detection sensor detects the gap or opening amount of the parting surface between the fixed side and the movable side mold due to the pressure of the injection resin, and by power such as hydraulic pressure, An apparatus having a mechanism for controlling the mold deformation amount to be zero or relatively zero is disclosed (Patent Document 4).

In addition, by detecting the deformation that occurs between the fixed and movable molds due to the pressure of the injection resin with the displacement detection sensor and controlling the injection speed or injection pressure of the resin in the injection molding machine, the mold of the mold A device having a mechanism for reducing displacement in the opening direction and extending deformation of the cavity is disclosed (Patent Document 5).

Compression molding metal that can detect the resin pressure in the cavity, displacement of the core and movable mold, etc. with a pressure sensor or displacement sensor, etc., and can control the compression of resin in the independent cavity in units of cores using piezoelectric elements A mold is disclosed (Patent Document 6).

A mechanism having a mechanism capable of stopping the slide core at a position other than the normal position when the position of the slide core driven by the cylinder is detected by a sensor and abnormality of the insert part in the mold is detected is disclosed. (Patent Document 7).

The molding methods described in Patent Documents 4 to 6 are not related to a mold that abuts a plurality of slide cores to form an optical transfer surface, but are directly applied to a mold that abuts slide cores. However, it does not solve the problems related to the slide core, that is, it does not prevent the formation of burrs in the gap around the slide core while preventing the optical transfer surface from deteriorating.

On the other hand, the molding method disclosed in Patent Document 7 is applied to a mold of a type in which slide cores are brought into contact with each other. However, the slide core is only stopped at a position other than the normal position when an abnormality is detected. That is, in Patent Document 7, when molding is performed while preventing the optical transfer surface formed on the slide core or the like from being deformed and deteriorated by pressurization, the pressurization is insufficient and the gap between the slide core and the like is reduced. There is no disclosure of a technique for preventing burrs from being formed by the resin entering.

JP-A-3-181913 Japanese Patent Laid-Open No. 10-186116 JP-A-3-42222 Japanese Patent Laid-Open No. 4-27516 JP-A-4-004117 JP 2003-094499 A Japanese Patent Laid-Open No. 10-296736

The present invention relates to an optical product molding apparatus and a manufacturing method capable of preventing a resin from entering a gap of a slide core or the like and forming burrs while preventing the optical surface of the optical product from being deteriorated due to deformation of the optical transfer surface. It aims to provide a method.

In order to achieve the above object, an optical product molding apparatus according to the present invention measures a contact pressure of a contact surface between a molding die including a slide core having an optical transfer surface and another member due to movement of the slide core. A contact pressure sensor, a position adjusting unit that adjusts the position of the slide core, and at the start of resin injection in the molding process, the position adjusting unit secures a gap between the slide core and another member and before the resin injection is completed. And a control unit that brings the slide core and another member into contact with each other by the position adjusting unit based on the output of the contact pressure sensor.

In the molding apparatus, when the resin injection is started in the molding process, the position adjusting unit secures a gap between the slide core and the other member, so the resin remaining sufficiently in the mold space is sufficiently filled with the resin. Can do. Furthermore, before the resin injection is completed, based on the output of the contact pressure sensor, the slide core and the other member are brought into contact with each other by the position adjusting unit. Deformation can be prevented, and deterioration of the optical surface of the optical product can be prevented. Furthermore, since the contact of the contact surface of the slide core is ensured, it is possible to prevent a gap from being formed on the contact surface, and it is possible to prevent a resin from entering the gap and forming a burr.

In order to achieve the above object, an optical product molding method according to the present invention measures a contact pressure of a contact surface between a molding die including a slide core having an optical transfer surface and another member due to the movement of the slide core. An optical product molding method using a molding apparatus having a contact pressure sensor and a position adjusting unit for adjusting the position of the slide core, and using the output of the contact pressure sensor at the start of resin injection in the molding process. The position adjustment unit secures a gap between the slide core and the other member, and before the resin injection is completed, the position adjustment unit contacts the slide core and the other member based on the output of the contact pressure sensor. Let

In the molding method described above, a gap is secured between the slide core and the other member by the position adjusting unit at the start of resin injection in the molding process, so that the resin is sufficiently filled while expelling air remaining in the mold space. Can do. Furthermore, before the resin injection is completed, based on the output of the contact pressure sensor, the slide core and the other member are brought into contact with each other by the position adjusting unit. Deformation can be prevented, and deterioration of the optical surface of the optical product can be prevented. Furthermore, since the contact of the contact surface of the slide core is ensured, it is possible to prevent a gap from being formed on the contact surface, and it is possible to prevent a resin from entering the gap and forming a burr.

It is a conceptual diagram explaining the shaping | molding apparatus of the optical product which concerns on one Embodiment of this invention. It is an end view explaining the structure of the movable type | mold which comprises the shaping | molding apparatus of FIG. It is a perspective view explaining structures, such as a movable type. It is a chart explaining the influence on the optical transfer surface of the contact pressure between contact surfaces. It is a perspective view explaining an example of the optical product shape | molded by the shaping | molding apparatus of FIG. It is a conceptual diagram explaining the whole structure of the shaping | molding apparatus incorporating the shaping | molding die shown by FIG. It is a flowchart explaining operation | movement of the shaping | molding apparatus shown by FIG. It is a flowchart explaining operation | movement of the shaping | molding apparatus shown by FIG. 9A and 9B are enlarged perspective views for explaining the operation of the molding apparatus shown in FIG. 1 and the like. It is an expanded sectional view explaining the operation state of the shaping | molding apparatus shown by FIG. It is a graph explaining the change of the resin pressure after resin injection. It is an end view explaining the type | mold structure of a modification.

Hereinafter, embodiments of an optical product molding apparatus and a manufacturing method thereof according to the present invention will be described with reference to the drawings.

FIG. 1 is a conceptual diagram for explaining a main part of an optical product molding apparatus. 1 includes a portion corresponding to the AA cross section of the molding die shown in FIG. 2 described later.

The optical product molding apparatus 100 includes a molding die 40, a die associated mechanism 50, and a control device 30.

The molding die 40 includes a first die 41 and a second die 42. The first mold 41 on the movable side of the molding die 40 can be reciprocated in the AB direction which is the opening / closing direction by a mechanism which will be described later. A mold for molding an optical product OP, which will be described later, by moving the first mold 41 in the direction A (upper side of the drawing) and clamping the first mold 41 and the second mold 42 as shown in the figure. A cavity CV, which is a space, is formed.

2 and 3 are an end view and a perspective view for explaining the structure of the first mold 41 on the movable side, the die associated mechanism 50, and the like.

As shown in FIGS. 1 to 3, the first mold 41 includes a mold structure 61 that is an assembly of a plurality of members arranged on the end surface side in the + Z direction, that is, the second mold 42 side, and the −Z direction. And a receiving plate 62 disposed on the back side of the. Among these, the mold structure 61 includes a fixed core 71 disposed in the center, four slide cores 72 that are opposed to each other with the fixed core 71 interposed therebetween, and four supports that respectively support the slide core 72 from behind. 73 and four sets of guide members 74 for guiding the slide core 72 or the support 73 to move forward and backward.

The fixed core 71 is fixed on the receiving plate 62. The fixed core 71 has a top surface 71a and a side surface 71b as transfer surfaces, but these

surfaces

71a and 71b are not optical transfer surfaces.

The four slide cores 72 surrounding the fixed core 71 are also referred to as slide blocks, and are provided at four equal intervals around the fixed core 71 along the XY plane (specifically, the support surface 62a of the receiving plate 62). Yes. Thus, by arranging the plurality of slide cores 72, the cavity CV can be formed so as to be sandwiched between the plurality of slide cores 72, and the degree of freedom of the shape of the optical product OP can be increased. Each slide core 72 can move forward and backward toward a central axis CX passing through the center of the fixed core 71. Specifically, the pair of slide cores 72 corresponding to the + X and + Y directions and the −X and −Y directions in FIG. 2 move along the CD direction and approach or separate from each other. The pair of slide cores 72 corresponding to the + X and −Y directions and the −X and + Y directions move along the EF direction and approach or separate from each other. In the illustrated example, each slide core 72 has a quadrangular prism-shaped outer shape, and an inner side surface 72a on the tip side is an optical transfer surface. The lower surface 72c (see FIG. 1) of each slide core 72 is a smooth surface so as to be supported by a support surface 71d provided on the fixed core 71 and to be slidable. The side surface 72d and the upper surface 72e of each slide core 72 are also smooth surfaces. Each slide core 72 has a pair of contact surfaces 72p adjacent to the inner surface 72a. These contact surfaces 72p extend perpendicular to the support surface 62a, which is the surface of the receiving plate 62, and are orthogonal to the XY plane. The contact surface 72p is a part that prevents the gaps between the four slide cores 72 from being formed by closing the side surfaces of the cavity (mold space) CV when the adjacent slide cores 72 are in contact with each other. On the other hand, a pair of opposing contact surfaces 72p are separated by a predetermined interval as the slide core 72 is retracted, and air in the cavity CV can be removed during resin injection. In this case, for one of the adjacent slide cores 72, the other is another member to be abutted.

The support body 73 is a block-shaped member, is connected to the outer surface on the base side of the slide core 72, and moves in the CD direction or the EF direction together with the slide core 72. The lower surface 73c of the support 73 is a smooth surface so as to be supported by the support surface 62a of the receiving plate 62 and to be slidable. On the side surface of the support 73, a step 73d that fits smoothly with the guide member 74 is formed.

The pair of guide members 74 arranged so as to sandwich the support member 73 from the side thereof is a set, and is fitted with a step 73d of the support member 73 to guide the movement of each support member 73. The guide member 74 is fixed to the receiving plate 62 by a member (not shown).

The second mold 42 is a fixed mold and includes a mold structure 161 disposed on the end surface side thereof, that is, the first mold 41 side, and a receiving plate 162 disposed on the back surface side. Among these, the mold structure 161 includes a fixed core 81 disposed in the center and four blocks 84 disposed so as to surround the periphery of the fixed core 81.

The fixed core 81 is fixed on the receiving plate 162. The fixed core 81 has a top surface 81a and a side surface 81b as transfer surfaces, but neither of these

surfaces

81a and 81b is an optical transfer surface. A sprue port 81i is formed in the top surface 81a of the fixed core 81, and the sprue port 81i communicates with a sprue 42j for supplying molten resin from the outside to the inside.

The four blocks 84 surrounding the fixed core 81 serve to bring the four slide cores 72 close to the fixed core 71 in advance when the first mold 41 and the second mold 42 are closed and clamped. That is, when the first mold 41 is moved in the direction A (upper side in FIG. 1) close to the second mold 42, the support 73 comes close to each block 84, and the

slopes

84s and 73s come into contact with each other. Further, when the operation of bringing the first mold 41 close to the second mold 42 is continued, the four support bodies 73 and the four slide cores 72 supported by the four support bodies 73 are sandwiched by the four blocks 84 and close to each other. In the stage where the molds are gradually moved in the direction and the mold clamping is completed, the pair of facing contact surfaces 72p of the adjacent slide cores 72 are in a state of being appropriately close to each other. That is, preliminary mold closing in the lateral direction of the slide core 72 is performed by the block 84 or the like. This preliminary mold closing ensures a wide gap formed between the slide cores 72 as compared to a gap securing state described later.

When the first mold 41 is moved in the A direction and the

molds

41 and 42 are clamped, the fixed core 71 of the first mold 41 and the fixed core 81 of the second mold 42 are not shown. The distance between the fixed core 71 and the fixed core 81 is adjusted to a specified value. At this time, the upper surface 72e of the slide core 72 and a part of the fixed core 81 are arranged close to each other. As a result, the slide core 72 has a peripheral surface extending in the CD direction surrounded by the fixed core 71 and the fixed core 81, and the movement in the CD direction is permitted while the movement perpendicular to the CD direction is restricted. It becomes.

In addition, a rod 86 is obliquely inserted and fixed in a hole 84 h provided in each block 84 that enables the slide core 72 to be closed in the lateral direction. The rod 86 is fixed to the hole of the support 73. 73h has a predetermined play and is slidably inserted. Thus, when the first mold 41 is moved in the B direction (lower side in FIG. 1) away from the second mold 42, the first support 41 is guided by the rods 86 extending from the blocks 84, and the support bodies 73 are mutually connected. It retreats so that it may space apart, and each corresponding slide core 72 also retreats so that it may mutually space apart. That is, when the mold is opened, if the first mold 41 and the second mold 42 are separated from each other, the four slide cores 72 are retracted so as to be separated from each other, and the mold opening in the lateral direction is also achieved. Conversely, when the first mold 41 is moved in the A direction (upper side of the drawing in FIG. 1) close to the second mold 42, the first mold 41 is guided by the rod 86 extending from each block 84, and the support 73 and the slide core 72. Move forward so that they are close to each other. In addition, since play is provided between the rod 86 and the hole 73h, the support 73 can be finely moved in the CD direction with respect to the block 84.

1 is attached to the four slide cores 72. As shown in FIG. The die attachment mechanism unit 50 includes an actuator 52 that supports the slide core 72 from the outside and adjusts the position, and a contact pressure sensor 54 that measures the contact pressure of the contact surface 72p due to movement of the slide core 72 such as advancement. Among these, the actuator 52 constitutes a position adjusting unit 59 that supports the slide core 72 and adjusts its position, and adjusts the contact pressure of the contact surface 72p of the slide core 72. An actuator (position adjusting unit) 52 is provided in each of the four slide cores 72. On the other hand, the contact pressure sensor 54 is provided between the adjacent slide cores 72. The die attachment mechanism portion 50 is accompanied by an urging member 53 made of a spring or the like, and the urging member 53 provides power for moving the slide core 72 backward after the die is opened.

Actuator (position adjustment unit) 52 is a telescopic device for position adjustment, and is sandwiched between fixed core 71 and support 73. More specifically, the actuator 52 is made of a piezoelectric element, one end is fixed to the inner portion 73 f of the support 73, and the other end is in contact with the outer edge portion 71 f of the fixed core 71. The actuator 52 adjusts the contact pressure on the contact surface 72p of the slide core 72 by expansion and contraction. Thereby, the contact pressure of the contact surface 72p can be made appropriate while the slide core 72 is appropriately advanced and retracted by the actuator 52 to adjust the position. In addition, since the actuator 52 includes a piezoelectric element, and the piezoelectric element is small and thin, the contact pressure can be adjusted while ensuring the degree of freedom of the arrangement and shape of the slide core 72. The actuator 52 is driven by a position adjustment drive circuit 33 a provided in the position adjustment control unit 33 to expand and contract. When the actuator 52 expands and contracts, the movable support 73 moves in the CD direction along the cross section of FIG. 1, and the slide core 72 supported by the support 73 also moves in the CD direction along the cross section of FIG. . The moving direction of the slide core 72 is guided by the fixed core 71 and the like, and is along the support surface 62 a of the receiving plate 62.

The contact pressure sensor 54 includes a strain gauge, a piezoelectric element, and the like, and is attached to be embedded in one of the contact surfaces 72p between a pair of adjacent slide cores 72. The contact pressure sensor 54 is driven by a sensor drive circuit 33c provided in the position adjustment control unit 33 and detects the contact pressure at the contact surface 72p. In a state where the contact surface 72p of one slide core 72 is not in contact with the contact surface 72p of the other slide core 72, the detection output of the contact pressure sensor 54 becomes zero, and the contact surface 72p comes into contact and the compression stress acts strongly. The detection output of the contact pressure sensor 54 increases as the detection pressure increases, and the detection output indicates the degree of contact pressure. When the contact pressure detected by the contact pressure sensor 54 is zero or less, it is determined that the gap between the contact surfaces 72p is widened. On the other hand, when the contact pressure detected by the contact pressure sensor 54 is greater than zero, a gap is not formed between the contact surfaces 72p and the contact state is ensured, but the contact pressure becomes excessive and the optical transfer surface of the slide core 72 is increased. It is necessary to prevent deformation of the inner side surface 72a. The contact pressure sensor 54 is used for monitoring so that the contact pressure becomes a target value within a range that does not cause deformation of the inner side surface 72 a that is the optical transfer surface of the slide core 72.

FIG. 4 shows the result of simulation of the contact pressure between the contact surfaces 72p and the deformation of the inner surface 72a of the slide core 72. As is apparent from the chart, it can be seen that the deformation of the optical transfer surface increases to a degree that cannot be ignored according to the increase in the contact pressure between the contact surfaces 72p, and it is understood that the control of the contact pressure between the contact surfaces 72p is important.

As shown in FIG. 5, the optical product OP produced by the molding apparatus 100 shown in FIG. 1 and the like is specifically a polygon mirror, has a quadrangular prism appearance, and the outer side surfaces of the four wall portions WP are , Each function as a mirror MR. The four mirrors MR are evenly arranged around the optical axis OA. A partition wall PA that partitions the optical product OP up and down is formed inside the wall WP, and functions as a part for supporting the optical product OP when the optical product OP is assembled to the apparatus. The outer shape of the optical product OP corresponds to the inner surface shape of the cavity CV that is a space sandwiched between the first mold 41 and the second mold 42 shown in FIG.

Note that the illustrated optical product OP is merely an example, and optical products having various shapes can be manufactured by the molding apparatus 100 illustrated in FIG. 1 and the like. For example, even if the optical product is a polygon mirror, the number of mirrors can be 6 or 8 according to the required specifications. Further, a polygon mirror having a two-stage configuration along the optical axis may be used. In the case of a polygon mirror having a two-stage configuration, there is a case where the outer shape is a drum shape or a pincushion shape in which the diameter is larger at both ends along the optical axis at the center and the mirrors adjacent in the optical axis direction face each other. Furthermore, the optical product OP is not limited to a polygon mirror, but may be a prism or other optical element.

Referring to FIG. 6, the overall structure of the molding apparatus 100 shown in FIG. 1 will be described. The molding apparatus 100 includes an injection molding machine 10 that is a main body part that performs injection molding to produce an optical product OP, and a control device 30 that comprehensively controls the operation of each part of the molding apparatus 100.

The injection molding machine 10 is a horizontal molding machine and includes a fixed platen 11, a movable platen 12, an opening / closing drive device 15, and an injection device 16 in addition to the molding die 40 described above. The injection molding machine 10 is also provided with a mold temperature controller 91 and the like. 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 fixed on the support frame 14 detachably supports the second mold 42. The fixed platen 11 is formed with an opening 11b through which a nozzle 21 described later is passed. The opening 11b communicates with the sprue 42j in FIG.

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 movable platen 12 detachably supports the first mold 41.

The opening / closing drive device 15 is supported by the mold clamping board 13, and includes a linear guide 15a, a power transmission unit 15d, and a board actuator 15e. The power transmission unit 15 d expands and contracts by receiving a driving force from the panel actuator 15 e that operates under the control of the control device 30. Thereby, the fixed platen 11 and the movable platen 12 can be brought close to or away from each other, and the first mold 41 and the second mold 42 can be clamped or opened.

The injection device 16 includes a feed unit 16a, a raw material storage unit 16b, a drive unit 16c, and the like. The injection device 16 operates at an appropriate timing under the control of the control device 30 and is a molten resin in which the temperature and the filling pressure are controlled from the resin injection nozzle 21 provided at the tip of the feed portion 16a. Can be injected at a desired timing, and holding pressure for maintaining the injection pressure of the molten resin can be performed after the resin injection.

A mold temperature controller 91 attached to the injection molding machine 10 circulates a temperature-controlled heat medium in both

molds

41 and 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 control device 30 includes an opening / closing control unit 31, an injection device control unit 32, a position adjustment control unit 33, and a storage unit 34. The open / close control unit 31 enables the

molds

41 and 42 to be closed, clamped, opened, and the like by operating the panel actuator 15e. The injection device control unit 32 causes the molten resin to be injected at a desired pressure into the cavity CV formed between the

molds

41 and 42 by appropriately operating the feed unit 16a, the drive unit 16c, and the like.

The position adjustment control unit 33 operates the die accompanying mechanism unit 50 including the actuator 52 and the contact pressure sensor 54 after the mold clamping. Specifically, the position adjustment control unit 33 uses the detection output of the contact pressure sensor 54 to determine whether or not the contact pressure of the contact surface 72p of the adjacent slide core 72 is within an appropriate setting range. . The position adjustment control unit 33 adjusts the position of the slide core 72 by operating the actuator 52 when the contact pressure of the contact surface 72p is out of an appropriate setting range. Specifically, the actuator 52 is operated to properly maintain the contact state between the slide cores 72 so that the inner side surface 72a that is the optical transfer surface is not excessively deformed. Further, the position adjustment control unit 33 operates the actuator 52 as appropriate to retract the slide core 72 from a state where the contact surface 72p is in contact so that a gap between the facing contact surfaces 72p becomes a predetermined interval or distance. You can also. Specifically, the position adjustment control unit 33 operates the actuator 52 based on the detection output of the contact pressure sensor 54 and, for example, adjusts the contact pressure of the contact surface 72p once to a specified value close to zero, The slide core 72 is retracted by a predetermined amount by extending the actuator 52 by a predetermined amount. Thereby, the clearance gap of a predetermined space | interval can be formed between a pair of adjacent contact surfaces 72p. It should be noted that the control for extending the actuator 52 by a predetermined amount can be performed in an open loop. However, when the actuator 52 includes a position sensor, feedback using the position sensor is performed. Control, that is, the detection output of the position sensor can be used to maintain the actuator 52 in an initially extended state.

Although detailed description is omitted, the four slide cores 72 are linked to each other, and the die-associated mechanism unit 50 associated therewith is also linked to operate. In other words, the contact pressure of the contact surface 72p is set to an appropriate setting range so as not to be biased toward the specific slide core 72. For example, when it is determined from the measurement value of the contact pressure sensor 54 between a pair of adjacent slide cores 72 that the contact pressure should be returned to an appropriate range, the driving amount of the actuator 52 is distributed to the pair of slide cores 72. Alternatively, the feedback amount is calculated. In the following description of the operation, such a drive amount or feedback amount is distributed, but the description thereof is omitted. Further, when measurement values from two or more contact pressure sensors 54 are obtained for the same slide core 72, the driving amount or feedback amount of the actuator 52 is calculated from the average value thereof. However, the driving amount of the actuator 52 or the like may be calculated so that the measured values from the two or more contact pressure sensors 54 are all within the appropriate range of the contact pressure. With the control as described above, even when gaps are formed between the plurality of contact surfaces 72p, these gaps can be balanced.

Hereinafter, a method of manufacturing the optical product OP using the molding apparatus 100 shown in FIGS. 1 and 6 will be described with reference to FIGS.

First, the control device 30 operates the opening / closing drive device 15 to advance the movable platen 12 to start mold closing and mold clamping (step S11). Note that both

molds

41 and 42 are heated in advance by a mold temperature controller 91 to a temperature suitable for molding.

Subsequently, the control device 30 operates the position adjustment control unit 33 to start feedback control for making the position of the slide core 72 appropriate (step S12). Specifically, the position adjustment control unit 33 sets the actuator 52 to an initial operation state, and initializes the arrangement of the slide core 72. The position adjustment control unit 33 reads the initial target value of the contact pressure of the contact surface 72p from the storage unit 34, and takes in the detection output of the contact pressure of the contact surface 72p by the contact pressure sensor 54. Thereby, the position of the slide core 72 can be feedback controlled by the actuator 52 so that the contact pressure detected by the contact pressure sensor 54 becomes the initial target value.

After the feedback control is started, the position adjustment control unit 33 determines whether or not the contact pressure detected by the contact pressure sensor 54 is within the setting range, that is, the detected value m of the contact pressure is a target value NI close to zero. If the contact pressure detection value m is larger than the target value NI or smaller than the target value NI, that is, if the detection value m is different from the target value NI, the actuator 52 is turned on. By operating (step S14), the slide core 72 is moved forward or backward. Here, the target value NI is a value close to zero and does not cause deformation on the optical transfer surface of the slide core 72.

When it is determined in step S13 that the detected value m of the contact pressure is different from the target value NI, in step S14, the position adjustment control unit 33 calculates the drive amount of the actuator 52 so as to compensate for this, and the actuator 52 To perform an operation corresponding to the driving amount. That is, the position adjustment control unit 33 increases or decreases the dimension of the actuator 52 by the amount corresponding to the driving amount. By such an operation of the actuator 52, the slide core 72 supported from the rear by the support body 73 moves forward or backward by an amount corresponding to the driving amount of the actuator 52.

As a result, the slide cores 72 come into contact with the contact surfaces 72p, and the contact pressure between the contact surfaces 72p is close to zero. Specifically, as shown in FIG. 9A, as shown in FIG. 9B, even when the contact surfaces 72p of the adjacent slide cores 72 are initially separated from each other and the gap GA is formed, as shown in FIG. The surfaces 72p are in contact with each other, and there is almost no gap GA.

When it is determined that the detected value m of the contact pressure is equal to the target value NI (m = NI in step S13), the position adjustment control unit 33 extends the actuator 52 by a predetermined amount to move the slide core 72. The clearance GA is retracted so that the gap GA between the opposing contact surfaces 72p becomes a predetermined interval (step S15). Thereby, it is possible to prevent the optical transfer surface of the slide core 72 from being deformed such as warping or bending during mold clamping.

After that, the position adjustment control unit 33 confirms the completion of the mold clamping of both

molds

41 and 42, and waits until the mold clamping is completed when the mold clamping is not completed (step S16). When the mold clamping is completed, the first mold 41 and the second mold 42 are clamped with a necessary pressure. Since the gap GA is secured between the contact surfaces 72p in step S15, the cavity GA is formed in the cavity CV formed inside the slide core 72 at the location of the contact surface 72p. Yes. Such a gap GA is referred to as an air vent gap, and a state in which such a gap GA is formed is referred to as a gap securing state.

As described above, in order to secure a gap between the slide cores 72, the actuator 52 once realizes a contact state in which the output of the contact pressure sensor 54 indicates contact based on the output of the contact pressure sensor 54, and from the contact state. The state where the slide core 72 is retracted by a predetermined amount is maintained. Thereby, a gap can be secured between the slide cores 72 using the output of the contact pressure sensor 54.

Next, the control device 30 operates the injection device 16 to inject the molten resin into the cavity CV between the clamped first mold 41 and the second mold 42 at a necessary pressure. To start filling the resin (step S22). The position adjustment control unit 33 receives an injection start signal indicating the start of the injection operation of the injection device 16 from the control device 30. At this time, since the clearance GA is formed at the location of the contact surface 72p of the cavity CV as the clearance securing state in step S15, the air is quickly introduced into the cavity CV while eliminating the air in the cavity CV. Or it can be filled with resin.

After that, the position adjustment control unit 33 determines whether or not it is a predetermined timing to start closing the gap (step S122). Whether or not it is a predetermined timing for starting the gap closing is set in accordance with the progress of air removal in the cavity CV. For example, as shown in FIG. 10, if the resin MM is substantially filled in the cavity CV and the air removal is substantially completed, it is determined that the gap closing start timing is reached. In this way, when it is determined that the gap closing start timing is reached, the resin pressure in the cavity CV starts to rise, so it is necessary to close the gap between the slide cores 72 to prevent the resin from protruding into the gap.

FIG. 11 is a graph conceptually illustrating the timing for starting the gap closing. The horizontal axis represents time (seconds), and the vertical axis represents the screw pressure when the resin is supplied by the injection device 16. T1 is when injection is started, and T2 is when switching to holding pressure. The injection time T2-T1 is a time for filling the cavity CV with resin, and is determined by the injection speed and the capacity of the cavity CV. Generally, the injection time T2-T1 is set to about several seconds. T3 is a timing at which the gap between the slide cores 72 starts to close, and the gap between the slide cores 72 is closed almost instantaneously. Timing T3 which means the transition from the gap securing state to the gap closing start assumes a state where resin MM is almost entirely filled in the cavity CV, as shown in FIG. When the pressure is once maintained constant and is in a stable state, it can be handled that the timing T3 has been substantially reached. In a specific operation example, the switching waiting time T3-T1 from the start of injection to closing the gap is set to about half to about 3/4 of the injection time T2-T1. Note that the switching standby time T3-T1 can be set within a range in which the burr is not formed by actually manufacturing the optical product OP.

When it is determined that the gap closing start timing is determined (Y in step S122), the position adjustment control unit 33 performs feedback control of the position of the slide core 72 so that the contact pressure sensor 54 detects a predetermined contact pressure. The slide core 72 is advanced to bring the contact surfaces 72p into contact with each other. Specifically, the position adjustment control unit 33 determines whether or not the contact pressure detected by the contact pressure sensor 54 is within the set range, that is, whether or not the detected value m of the contact pressure is the target value N. Is determined (step S23). Here, the target value N can be a single numerical value of zero or more. Further, the target value N can be a numerical range having a predetermined width. The target value N is set so that the detected value m of the contact pressure is within a range in which the optical transfer surface of the slide core 72 is not deformed. This target value N can be made to coincide with the target value NI in step S13 described above, but it is not necessary to make it coincide with the target value NI.

If the detected value m of the contact pressure is different from the target value N, the position adjusting actuator 52 is operated (step S24). Specifically, when the detected value m of the contact pressure is different from the target value N (N ≠ m in step S23), particularly when the detected value m of the contact pressure is larger than the target value N, or the detected value m is the target value N. When the position is close to, the position adjustment control unit 33 operates the actuator 52 to move the slide core 72 backward or back and forth by a small amount. When it is determined that the detected value m of the contact pressure is different from the target value N, the position adjustment control unit 33 calculates the driving amount of the actuator 52 so as to compensate for this, and the actuator 52 operates corresponding to the driving amount. To do. That is, for example, when the detected value m of the contact pressure is larger than the target value N, the position adjustment control unit 33 increases the dimension of the actuator 52 corresponding to the driving amount or drives the urging force applied by the actuator 52. Increase as much as the amount. Due to the operation of the actuator 52, the slide core 72 supported on the support 73 from the rear moves backward by an amount corresponding to the drive amount of the actuator 52. On the other hand, when the detected value m of the contact pressure is smaller than the target value N, the reverse operation is performed and the slide core 72 is given or appropriately moved forward. Thus, the contact pressure can be prevented from exceeding the target range, and the state can be stably maintained.

In the present embodiment, it is not assumed that the detected value m of the contact pressure is significantly smaller than the target value N. That is, if the detected value m of the contact pressure is significantly smaller than the target value N, for example, close to zero, the slide core 72 is being pushed back to the resin pressure. In this case, the actuator 52 only resists this. Is not always easy. In the case of the present embodiment, the detection value m of the contact pressure becomes excessively smaller than the target value N due to the restriction of the mechanical movement using the rod 86, that is, the support 73 and the slide core 72 are moved backward too much. Is surely prevented.

As described above, with respect to the driving amount of the actuator 52, a certain limit can be provided for the adjustment width or the pressure adjustment width. That is, the amount of feedback to the actuator 52 can be limited, and the size or urging force of the actuator 52 can be reduced in units of the upper limit adjustment width or pressure adjustment width. In this case, by making the adjustment width or the pressure adjustment width small, it is possible to gradually achieve the transition from the gap securing state to the gap closing start. Furthermore, the transition from the gap securing state to the gap closing start can be nonlinearly advanced by program control.

As described above, the position of the slide core 72 is controlled by the actuator 52 so that the slide cores 72 are separated from each other by a predetermined interval before the predetermined timing during the resin injection, and after the predetermined timing, The position of the slide core 72 is feedback-controlled by the actuator 52 so that the contact pressure at the contact surface 72p becomes a target value within a range in which the optical transfer surface of the slide core 72 is not deformed. Thereby, it is possible to prevent the optical transfer surface of the slide core 72 from being deformed such as warping or bending during injection, and it is possible to prevent the gap GA from being formed on the contact surface 72p of the slide core 72 and the formation of burrs.

Further, by setting a predetermined timing regarding the start of advancement of the slide core 72 in accordance with the progress of the air removal in the cavity CV, it is possible to ensure the air removal in the cavity CV and to prevent the variability caused by the gap between the slide cores 72. Can be prevented. That is, the resin injected into the cavity CV can be prevented from protruding into the gap GA by moving the slide core 72 forward after a predetermined timing and closing the gap between the slide cores 72. On the other hand, by adjusting the drive amount of the actuator 52, the contact pressure of the contact surface 72p does not exceed the allowable value as the slide core 72 advances, so that the inner side surface 72a that is the optical transfer surface is deformed. Can be prevented. That is, in the optical product OP shown in FIG. 5, it is possible to prevent the occurrence of burrs due to the gap between the slide cores 72. Note that the position of the slide core 72 can be maintained against the resin filling pressure by setting the target value N for controlling the contact pressure to a predetermined value of zero or more.

When it is determined that the detected value m of the contact pressure is the target value N (N = m in step S23), the position adjustment control unit 33 checks whether or not the resin filling is substantially completed. (Step S26). When the resin filling is not substantially completed (N in step S26), the process returns to step S23, and steps S23 and S24 are repeated until the resin filling is substantially completed, so that the detected value m of the contact pressure is the target. The actuator 52 is operated until the value N is reached.

As a result, the state in which the contact surface 72p of the slide core 72 is in close contact with each other is maintained until the injection or filling of the resin is completed.

When the resin filling is substantially completed and the resin injection is finished (Y in step S26), the pressure holding cycle is started (step S32). During the pressure-holding cycle, the control device 30 operates the injection device 16 as appropriate to maintain the resin pressure in the cavity CV between the

molds

41 and 42, thereby improving the resin filling property.

At the time of holding pressure, the position of the slide core 72 is feedback-controlled by the actuator 52 so that the contact pressure at the contact surface 72p of the slide core 72 becomes a target value within a range in which the optical transfer surface of the slide core 72 is not deformed. . Thereby, it is possible to prevent the optical transfer surface of the slide core 72 from being deformed such as warping or bending during pressure holding, and it is possible to prevent the gap GA from being formed on the contact surface 72p of the slide core 72 to form burrs. .

After the start of the pressure holding cycle, the position adjustment control unit 33 determines whether or not the contact pressure detected by the contact pressure sensor 54 is within the set range, that is, whether or not the detected value m of the contact pressure is the target value N. It is determined whether or not (step S33). If the detected value m does not match the target value N, the position adjustment control unit 33 operates the position adjusting actuator 52 to match the detected value m of the contact pressure with the target value N. Note that, for example, when the detected value m of the contact pressure is larger than the target value N, the method of operating the actuator 52 for position adjustment in step S34 is the same as step S24 after the start of resin filling or resin injection. The description is omitted.

When the pressure holding cycle is completed (Y in step S36), the cooling cycle is started (step S42). During the cooling cycle, the control device 30 operates the mold temperature controller 91 as appropriate to cool and solidify the resin in the cavity CV between the

molds

41 and 42.

At the time of cooling, the position of the slide core 72 is feedback-controlled by the actuator 52 so that the contact pressure on the contact surface 72p of the slide core 72 becomes a target value within a range in which the optical transfer surface of the slide core 72 is not deformed. Thereby, it is possible to prevent the optical transfer surface of the slide core 72 from being deformed such as warping or bending during cooling.

After the start of the cooling cycle, the position adjustment control unit 33 determines whether or not the contact pressure detected by the contact pressure sensor 54 is within the set range, that is, whether or not the detected value m of the contact pressure is the target value N. Is determined (step S43). If the detected value m does not match the target value N, the position adjustment control unit 33 operates the position adjusting actuator 52 to match the detected value m of the contact pressure with the target value N (step S44). Note that the method of operating the position adjusting actuator 52 in step S44 is the same as step S14 before the start of resin filling or resin injection, and a description thereof will be omitted.

When the cooling cycle is completed (Y in step S46), the control device 30 starts mold opening (step S51). And the control apparatus 30 complete | finishes the feedback control of the contact pressure by the position adjustment control part 33 (step S52). Finally, the control device 30 operates a take-out device (not shown) to take out the optical product OP from between the first and

second molds

41 and 42 after the mold is opened (step S53).

In the molding apparatus 100 for optical products described above, since the gap GA is secured between the slide cores 72 by the position adjusting unit 59 at the start of resin injection in the molding process, sufficient resin is expelled while expelling air remaining in the cavity CV. Can be filled. Furthermore, before the resin injection is completed, the slide cores 72 are brought into contact with each other by the position adjusting unit 59 based on the output of the contact pressure sensor 54, so that the contact pressure becomes excessive due to the abutment of the slide core 72 and the optical transfer surface. It is possible to prevent a certain inner side surface 72a from being deformed and to prevent the mirror MR, which is the optical surface of the optical product OP, from being deteriorated. Furthermore, since the contact of the contact surface 72p of the slide core 72 is ensured, it is possible to prevent the gap GA from being formed on the contact surface 72p, and to prevent the resin from entering the gap GA and forming burrs. .

FIG. 12 is a diagram for explaining a modified molding apparatus 100. In this case, a nest 78 is arranged as another member between the four slide cores 72. The insert 78 is supported by the fixed core 71, for example. Also in this case, by assembling the contact pressure sensor 54 to the slide core 72 and the insert 78, the contact pressure at the contact surface 72p can be monitored, and the inner side surface 72a, which is an optical transfer surface, can be prevented from being deformed. It is possible to prevent a gap that causes burrs from being formed between the side surface 72a and the insert 78.

As mentioned above, although this invention was demonstrated according to embodiment, this invention is not limited to the said embodiment. For example, the number of slide cores 72 is not limited to 4, and can be 2, 3,... According to the shape of the optical product.

Also, the actuator (position adjustment unit) 52 is not limited to a piezoelectric element, and can be replaced by a hydraulic or pneumatic driving device.

Further, in step S13 of FIG. 7, the actuator 52 can be gradually shortened from the beginning, and the operation of the actuator 52 can be stopped immediately when the detected value m becomes equal to or greater than the target value NI. In this case, after the operation of the actuator 52 is stopped, the process proceeds to step S15 in FIG. 7 so that the gap between the facing contact surfaces 72p becomes a predetermined interval.

In the above description, the gap between the opposing contact surfaces 72p is controlled only by the actuator (position adjusting unit) 52. However, if the resin pressure becomes excessive, the slide core 72 may be retracted beyond the initial state. . In consideration of such a case, an additional actuator can be provided in addition to the actuator 52. The additional actuator can be hydraulically or pneumatically operated. For example, the biasing member 53 can have a role.

Claims

A molding die including a slide core having an optical transfer surface;
A contact pressure sensor that measures a contact pressure of a contact surface with another member due to the movement of the slide core;
A position adjusting unit for adjusting the position of the slide core;
At the start of resin injection in the molding process, the position adjusting unit secures a gap between the slide core and the other member, and before the resin injection is completed, based on the output of the contact pressure sensor, the position An apparatus for molding an optical product, comprising: a control unit that brings the slide core and the other member into contact with each other by an adjustment unit.
In order to secure a gap between the slide core and the other member, the control unit has a contact state in which the output of the contact pressure sensor indicates contact by the position adjustment unit based on the output of the contact pressure sensor. The apparatus for molding an optical product according to claim 1, which is realized once and maintains a state in which the slide core is retracted by a predetermined amount from the contact state.
The control unit advances the slide core until the slide core comes into contact with the other member by the position adjusting unit based on an output of the contact pressure sensor after a predetermined timing during resin injection. 3. An apparatus for molding an optical product according to claim 1.
The optical product molding apparatus according to any one of claims 1 to 3, wherein the position adjusting unit is an actuator that adjusts a contact pressure on the contact surface of the slide core by expansion and contraction.
The apparatus for molding an optical product according to claim 4, wherein the actuator includes a piezoelectric element.
The said control part controls the position of the said slide core by the said actuator so that the said slide core and the said other member may be spaced apart by predetermined spacing at the time of mold closing of a formation process. An apparatus for molding an optical product according to claim 1.
The control unit controls the position of the slide core by the actuator so that the slide core and the other member are separated from each other by a predetermined interval before a predetermined timing during resin injection in the molding process, and After a predetermined timing, the position of the slide core is feedback-controlled by the actuator so that the contact pressure at the contact surface of the slide core becomes a target value within a range that does not cause deformation of the optical transfer surface of the slide core. The apparatus for molding an optical product according to any one of claims 4 to 6.
The controller controls the actuator so that the contact pressure at the contact surface of the slide core is a target value within a range that does not cause deformation of the optical transfer surface of the slide core at the time of holding pressure in the molding process. The optical product molding apparatus according to claim 4, wherein the position of the slide core is feedback-controlled.
The controller controls the slide by the actuator so that a contact pressure at the contact surface of the slide core becomes a target value within a range that does not cause deformation of the optical transfer surface of the slide core during cooling of the molding process. The apparatus for molding an optical product according to any one of claims 4 to 8, wherein the position of the core is feedback-controlled.
A plurality of the slide cores are arranged along the support surface of the molding die, the contact pressure sensor measures the contact pressure of the contact surfaces of the slide cores, and the position adjusting unit adjusts the position of each slide core. The apparatus for molding an optical product according to any one of claims 1 to 9.
A molding die including a slide core having an optical transfer surface; a contact pressure sensor for measuring a contact pressure of a contact surface with another member due to movement of the slide core; and a position adjusting unit for adjusting the position of the slide core; An optical product molding method using a molding apparatus comprising:
At the start of resin injection in the molding process, using the output of the contact pressure sensor, the position adjustment unit secures a gap between the slide core and the other member, and before the resin injection is completed, A method of manufacturing an optical product, wherein the position adjusting unit contacts the slide core and the other member based on an output of a contact pressure sensor.