WO2016167337A1

WO2016167337A1 - Device for molding optical product, and method for manufacturing optical product

Info

Publication number: WO2016167337A1
Application number: PCT/JP2016/062078
Authority: WO
Inventors: 田村義文; 高木信; 谷川裕海; 澤登大介; 高橋洋昭; 荒樋悟郎; 佐藤望; 阿部良幸
Original assignee: コニカミノルタ株式会社
Priority date: 2015-04-17
Filing date: 2016-04-15
Publication date: 2016-10-20
Also published as: JPWO2016167337A1

Abstract

Provided is a device for molding an optical product, whereby it is possible to prevent burring from forming while preventing deformation of an optical transfer face. A molding device 100 is provided with a molding die 40 including a slide core 72, a contact pressure sensor 54 for measuring contact pressure on a working face 72p of the slide core 72, a mold pressure imparting part 59 for adjusting the position of the slide core 72, and a mold pressure control part 33. After mold closure, the mold pressure control part 33 adjusts the position of the slide core 72 through use of a first actuator 52 on the basis of the output of the contact pressure sensor 54, and it is therefore possible to prevent an inside face 72a which is an optical transfer face from being deformed by excessive contact pressure resulting from abutting of the slide core 72, and to prevent degradation of a mirror MR which is the optical face of an optical product OP. Furthermore, because contact with the working face 72p of the slide core 72 is ensured, it is possible to prevent burring from being formed by intrusion of resin into a gap GA at the working face 72p.

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 mold pressure application unit that adjusts the position of the slide core, and a control unit that adjusts the position of the slide core by the mold pressure application unit based on the output of the contact pressure sensor after the mold is closed.

In the molding apparatus, after the mold is closed, the control unit adjusts the position of the slide core by the mold pressure applying unit based on the output of the contact pressure sensor, so that the contact pressure becomes excessive due to the abutment of the slide core. Deformation of the optical transfer surface 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 includes a molding die including a slide core having an optical transfer surface, and a contact pressure sensor that measures a contact pressure of a contact surface with another member due to movement of the slide core. An optical product molding method using a molding apparatus including a mold pressure application unit that adjusts the position of the slide core, and after the mold is closed, the slide core is formed by the mold pressure application unit based on the output of the contact pressure sensor. The contact pressure of the contact surface of the slide core is adjusted by adjusting the position of.

In the above molding method, after the mold is closed, the contact pressure of the contact surface of the slide core is adjusted by adjusting the position of the slide core by the mold pressure applying unit based on the output of the contact pressure sensor. It is possible to prevent the contact surface pressure from becoming excessive and the optical transfer surface from being deformed by the contact, and to prevent the optical transfer surface of the optical product from being deteriorated. 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 a movable structure. 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 operation | movement of the shaping | molding apparatus shown by FIG. 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 structures of the movable first mold 41 and the die-associated mechanism 50. FIG.

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 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). 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 that it can be slid by being supported by a support surface 71d provided in the fixed core 71 and perpendicular to the opening and closing direction. 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 can close the side surface of the cavity CV when the adjacent slide cores 72 come into contact with each other, and is a portion that prevents a gap from being formed between the four slide cores 72. ing. 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 portion 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 part 161 includes a fixed core 81 disposed in the center.

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.

When the second mold 42 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 mold part 161 of the second mold 42 are not connected. Abutting at the illustrated location, the distance between the fixed core 71 and the mold portion 161 is adjusted to a specified value. At this time, the upper surface 72e of the slide core 72 and the like and a part of the mold part 161 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 mold part 161, thereby restricting movement in the CD direction while allowing movement in the CD direction. It becomes a state.

1 is attached to the four slide cores 72. As shown in FIG. The die attachment mechanism 50 includes a first actuator 52 that supports the slide core 72 from the outside and adjusts the position, a second actuator 53 that supports the slide core 72 from the outside and applies a pressing force, and the slide core 72. A contact pressure sensor 54 that measures the contact pressure of the contact surface 72p due to movement such as forward movement. Among these, the 1st and

2nd actuators

52 and 53 comprise the mold pressure provision part 59 for adjusting the contact pressure of the contact surface 72p of the slide core 72. FIG. The first actuator 52 and the second actuator 53 are provided on 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 first actuator 52 is a telescopic device, and is sandwiched between the fixed core 71 and the support 73. More specifically, the first 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 first actuator 52 adjusts the contact pressure on the contact surface 72p of the slide core 72 by expansion and contraction. As a result, the contact pressure of the contact surface 72p can be made appropriate while adjusting the position by appropriately moving the slide core 72 forward and backward by the first actuator 52. In addition, since the first 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 first actuator 52 is driven by a position adjustment drive circuit 33 a provided in the mold pressure control unit 33 to expand and contract. When the first 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. Moving. 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 second actuator 53 is a pressure applying mechanism using hydraulic pressure or pneumatic pressure, and can support the support 73 from behind and press it forward. When the second actuator 53 includes the pressure application mechanism, it is possible to easily generate a pressing force against the resin pressure. The second actuator 53 includes a main body portion 53a and a rod 53b. The main body portion 53 a is fixed to the receiving plate 62. The main body portion 53a is driven by a pressing force driving circuit 33b provided in the mold pressure control unit 33 to expand and contract the rod 53b. Thereby, it is possible to prevent the slide core 72 from excessively moving backward toward the rear side or the second actuator 53 side. In other words, when the cavity CV is filled with resin, the slide core 72 receives a pressure to move backward due to the resin pressure. When a large gap is formed between the contact surfaces 72p of the adjacent slide cores 72, There is a possibility that the resin may enter and burr may be formed around the optical surface of the optical product OP. Therefore, the second actuator 53 supports the slide core 72 from the rear so that the gap between the contact surfaces 72p does not widen.

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 mold pressure control unit 33 and detects the contact pressure on 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 mold pressure 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 mold pressure control unit 33 operates the mold associated mechanism unit 50 including the first actuator 52, the second actuator 53, and the contact pressure sensor 54 after the mold clamping. Specifically, the mold pressure 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 mold pressure control unit 33 adjusts the position of the slide core 72 by operating the first actuator 52 when the contact pressure of the contact surface 72p deviates relatively small from an appropriate setting range. Specifically, the first actuator 52 is operated to properly maintain the contact state between the slide cores 72 so that the inner side surface 72a that is an optical transfer surface is not excessively deformed. On the other hand, the mold pressure control unit 33 operates the second actuator 53 to operate the slide core when the contact pressure of the contact surface 72p is relatively far from the appropriate setting range, particularly when the contact pressure is significantly below the lower limit of the appropriate setting range. Increase the pressing force to 72. Specifically, the second actuator 53 is operated so that the gap between the contact surfaces 72p of the slide core 72 is not excessive, and the resin is prevented from entering the gap and forming burrs.

In the above, the mold pressure control unit 33 gives the pressing force to the slide core 72 by the second actuator 53 with a correction amount coarser than the pressure adjustment range executed by the first actuator 52 according to the output of the contact pressure sensor 54. To do. As a result, the contact pressure is finely adjusted by the first actuator 52 while the contact actuator is roughly adjusted by the second actuator 53.

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 first actuator 52 or the The driving amount or feedback amount of the second actuator 53 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 amounts or feedback amounts of the first and

second actuators

52 and 53 are calculated from these average values. However, the drive amounts of the first and

second actuators

52 and 53 may be calculated so that all the measured values from the two or more contact pressure sensors 54 fall within the appropriate range of contact pressure.

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 mold pressure control unit 33 to start feedback control regarding the abutting state between the slide cores 72 (step S12). Specifically, the mold pressure control unit 33 sets the first actuator 52 and the second actuator 53 to an initial operation state, and initializes the arrangement of the slide core 72. Further, the mold pressure control unit 33 reads the 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 first actuator 52 so that the contact pressure detected by the contact pressure sensor 54 becomes the target value. By this feedback control, it is possible to prevent the optical transfer surface of the slide core 72 from being deformed such as warping or bending.

After the feedback control is started, the mold pressure control unit 33 determines whether or not the contact pressure detected by the contact pressure sensor 54 is within the set range, that is, the detected value m of the contact pressure is the target value N0 (Step S1). S13) When the detected value m of the contact pressure is larger than the target value N0 or smaller than the target value N0, the first actuator 52 is operated (step S14), and the slide core 72 is moved forward or backward. Here, the target value N0 is not limited to one numerical value (for example, a predetermined value of zero or more), but can be a numerical range having a predetermined width. Specifically, the target value N0 is, for example, a range from a predetermined lower limit value equal to or greater than zero to a predetermined upper limit value 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. It can be.

In step S13, when it is determined that the detected value m of the contact pressure is smaller than the target value N0, the mold pressure control unit 33 calculates the driving amount of the first actuator 52 so as to compensate for this, and the first actuator 52 is caused to perform an operation corresponding to the drive amount. That is, the mold pressure control unit 33 reduces the size of the first actuator 52 corresponding to the driving amount, or reduces the biasing force applied by the first actuator 52 only corresponding to the driving amount. By such an operation of the first actuator 52, the slide core 72 supported on the support body 73 from the rear advances or the like as much as the driving amount of the first actuator 52. Note that when the detected value m of the contact pressure is excessively smaller than the target value N0 (specifically, when it is less than or equal to zero), the second actuator 53 is supplementarily substituted for the first actuator 52. It is also possible to perform an operation to ensure that the contact pressure approaches the target value N0.

Conversely, if it is determined in step S13 that the detected value m of the contact pressure is greater than the target value N0, the mold pressure control unit 33 calculates the drive amount of the first actuator 52 so as to compensate for this, The first actuator 52 is caused to perform an operation corresponding to the drive amount. That is, the mold pressure control unit 33 increases the size of the first actuator 52 corresponding to the driving amount, or increases the biasing force applied by the first actuator 52 only corresponding to the driving amount. Due to the operation of the first actuator 52, the slide core 72 supported by the support 73 from the rear is retracted by an amount corresponding to the driving amount of the first actuator 52.

As a result, the contact surfaces 72p are in close contact with each other between the slide cores 72, and the contact pressure between the contact surfaces 72p is not less than the predetermined lower limit value of the target value N0 and not more than the predetermined upper limit value. Specifically, as shown in FIG. 9A, as shown in FIG. 9B, even if the contact surfaces 72p of the adjacent slide cores 72 are initially slightly separated from each other to form the gap GA, as shown in FIG. The contact surfaces 72p are in close contact with each other so that there is almost no gap GA.

In the above, with respect to the driving amount of the first 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 first actuator 52 can be limited, and the size or urging force of the first actuator 52 can be increased or decreased with the upper limit adjustment width or pressure adjustment width as a unit.

When it is determined that the detected value m of the contact pressure is the target value N0 (N0 = m in step S13), the mold pressure control unit 33 confirms completion of mold clamping of both the

molds

41 and 42, If the mold clamping has not been completed, the process waits until the mold clamping is completed (step S16). When the mold clamping is completed, the first mold 41 and the second mold 42 are clamped with a necessary pressure.

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).

After the resin filling is started, that is, at the time of resin injection, the mold pressure control unit 33 determines whether the contact pressure detected by the contact pressure sensor 54 is within the set range, that is, the detected value m of the contact pressure is larger or smaller than the reference value N. In addition, it is determined whether or not the target value N + Δ has been reached (step S23). Here, the reference value N is a threshold value for switching the

actuators

52 and 53 as will be described later, and is a predetermined value serving as a reference for switching determination. On the other hand, the target value N + Δ is a contact pressure allowed between the slide cores 72 and can be a single numerical value of zero or more. Further, the target value N + Δ can be a numerical range having a predetermined width. Specifically, the target value N + Δ can be set to a range from a predetermined lower limit value of zero or more to a predetermined upper limit value. The target value N + Δ 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 + Δ can be matched with the target value N0 in step S13 described above, but does not have to be matched with the target value N0. The reference value N for switching the actuator can be set to a value that is significantly smaller than the contact pressure allowed between the slide cores 72, for example. Specifically, for example, an operation of setting the actuator switching reference value N to zero Pa and the feedback control target value N + Δ by the first actuator 52 to 10 to several tens of kPa is possible.

If the detected value m of the contact pressure is equal to or greater than the reference value N (except for m = N + Δ), the first actuator 52 for position adjustment is operated (step S24). Specifically, when the detected value m of the contact pressure is greater than or equal to the reference value N (N ≦ m in step S23), the mold pressure control unit 33 operates the first actuator 52 to move the slide core 72 forward and backward.

That is, when the detected value m of the contact pressure is equal to or greater than the reference value N and the detected value m of the contact pressure is larger than the target value N + Δ, the mold pressure control unit 33 compensates for this. And the first actuator 52 is caused to perform an operation corresponding to the drive amount. That is, the mold pressure control unit 33 increases the size of the first actuator 52 corresponding to the driving amount, or increases the biasing force applied by the first actuator 52 only corresponding to the driving amount. By such an operation of the first actuator 52, the slide core 72 supported on the support body 73 from the back moves backward by the amount corresponding to the driving amount of the first actuator 52. Thereby, it is possible to prevent the contact pressure from exceeding the upper limit of the target. If the detected value exceeds the capability of the first actuator 52, the second actuator 53 may be operated to make an auxiliary adjustment.

On the other hand, if the detected value m of the contact pressure is greater than or equal to the reference value N and the detected value m of the contact pressure is smaller than the target value N + Δ, the mold pressure control unit 33 compensates for this. And the first actuator 52 is caused to perform an operation corresponding to the drive amount. That is, the mold pressure control unit 33 reduces the size of the first actuator 52 corresponding to the driving amount, or reduces the biasing force applied by the first actuator 52 only corresponding to the driving amount. By such an operation of the first actuator 52, the slide core 72 supported on the support 73 from the rear advances by the amount corresponding to the drive amount of the first actuator 52. This prevents the contact pressure from falling below the lower limit of the target.

In the above, with respect to the driving amount of the first 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 first actuator 52 can be limited, and the size or urging force of the first actuator 52 can be reduced in units of the upper limit adjustment width or pressure adjustment width.

When the detected value m of the contact pressure is smaller than the reference value N, the pressing second actuator 53 is operated (step S25). That the detected value m of the contact pressure is smaller than the reference value N means that the slide core 72 is moved backward by being pushed by the injection pressure of the molten resin.

Thus, when the detected value m of the contact pressure is smaller than the reference value N (N> m in step S23), the mold pressure control unit 33 operates the second actuator 53 to advance the slide core 72. When it is determined that the detected value m of the contact pressure is smaller than the reference value N, the mold pressure control unit 33 calculates the driving amount of the second actuator 53 so as to reliably compensate for this, and the second actuator 53 An operation corresponding to the driving amount is performed. That is, the mold pressure control unit 33 increases the pressing force applied from the second actuator 53 to the support 73 or the slide core 72 for an appropriate time corresponding to the driving amount. By the operation of the second actuator 53, a pressing force for moving the slide core 72 forward can be applied for a considerable time. Thereby, about the slide core 72 adjacent, the contact state between the contact surfaces 72p is securable.

As described above, with respect to the driving amount of the second actuator 53, a certain limit can be set to the correction width or the correction amount. That is, the feedback amount for the second actuator 53 can be limited, and the upper limit of the pressing force of the second actuator 53 can be reduced or the correction amount can be decreased as a unit.

As described above, when it is determined that the detected value m of the contact pressure has reached the target value N + Δ by operating the first actuator 52 while being assisted by the second actuator 53 (m = N + Δ in step S23), the mold The pressure control unit 33 confirms whether or not the resin filling is substantially completed (step S26). If the resin filling is not substantially completed (N in step S26), the process returns to step S23, and steps S23 to S25 are repeated until the resin filling is substantially completed, so that the detection value m of the contact pressure is the target. The first or

second actuator

52, 53 is operated so as to be maintained at the value N + Δ or to return to the target value N + Δ.

As a result, until the injection or filling of the resin is completed, the contact surface 72p of the slide core 72 is maintained in a moderately close state, and the slide core 72 is pushed back by the injection pressure of the molten resin. Can be avoided.

That is, as shown in FIG. 10, the slide core 72 receives the resin pressure P <b> 1 in the direction of being pushed back by the molten resin MM injected in the final stage of resin injection, but the first actuator 52 and the second actuator 53. By applying the pressing force P2 to push back to the slide core 72, the slide core 72 can be prevented from moving backward. Since the resin pressure P1 reaches, for example, 50 to 100 Mpa, the pressing pressure P2 also has a value balanced with this.

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.

After the start of the pressure holding cycle, the mold pressure control unit 33 determines whether or not the contact pressure detected by the contact pressure sensor 54 is within a set range, that is, the detected value m of the contact pressure is the target value N + Δ (step) S33). If the detected value m does not match the target value N + Δ, the mold pressure control unit 33 operates the first actuator 52 for position adjustment or the second actuator 53 for pressing to set the detected value m of the contact pressure to the target value. Match N + Δ. If the detected value m of the contact pressure is equal to or greater than the reference value N (except for m = N + Δ), the first actuator 52 for position adjustment is operated in step S34 and the detected value m matches the target value N + Δ. The method of performing is the same as that in step S24 after the start of resin filling or resin injection, and the description thereof is omitted. Further, when the detected value m of the contact pressure is smaller than the reference value N, the technique of operating the second actuator 53 for pressing in step S35 to make the detected value m larger than the reference value N is resin filling or resin This is the same as step S25 after the start of injection, and a description thereof will be omitted.

As described above, when the contact pressure on the contact surface 72p of the slide core 72 is lower than a predetermined value at the time of resin injection and holding pressure, the pressing force applied to the slide core 72 by the second actuator 53 is reduced to the predetermined value. increase. Further, the position of the slide core 72 is feedback-controlled by the first 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. As a result, it is possible to prevent the optical transfer surface of the slide core 72 from being deformed such as warping or bending at the time of injection and pressure holding, and a gap GA is formed on the contact surface 72p of the slide core 72 to form a burr. Can be prevented.

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.

After the start of the cooling cycle, the mold pressure control unit 33 determines whether or not the contact pressure detected by the contact pressure sensor 54 is within the set range, that is, the detected value m of the contact pressure is the target value N + Δ (step S43). ). If the detected value m does not match the target value N + Δ, the mold pressure control unit 33 operates the first actuator 52 for position adjustment to match the detected value m of the contact pressure with the target value N + Δ (step S44). . Note that the method for operating the first actuator 52 for position adjustment 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.

The feedback control by the first actuator 52 during cooling can prevent the optical transfer surface of the slide core 72 from being deformed such as warping or bending during cooling.

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 type | mold pressure 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, the mold pressure control unit 33 adjusts the position of the slide core 72 by the first actuator 52 based on the output of the contact pressure sensor 54 after the mold is closed. It is possible to prevent the inner surface 72a, which is the optical transfer surface, from being deformed due to excessive contact pressure due to the abutment of the core 72, 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. .

The mold pressure control unit 33 adjusts the position of the slide core 72 by the first actuator 52 based on the output of the contact pressure sensor 54 after the mold is closed, and the slide core 72 is pushed back by the resin pressure. In this case, the pressing force applied to the slide core 72 by the second actuator 53 is increased. As described above, after the resin is injected, when the slide core 72 is pushed back by the resin pressure, the mold pressure control unit 33 increases the pressing force applied to the slide core 72 by the second actuator 53. Even if the internal resin pressure increases, it is possible to reliably prevent the gap GA from being formed on the contact surface 72p of the slide core 72. In addition, by providing the first actuator 52 and the second actuator 53 as the mold pressure applying portion 59, the first actuator 52 and the second actuator 53 can have functions and roles according to the scene, and the slide The contact pressure at the contact surface 72p of the core 72 can be controlled more precisely.

FIG. 11 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.

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 mold pressure applying unit for adjusting the position of the slide core;
An optical product molding apparatus comprising: a control unit that adjusts the position of the slide core by the mold pressure applying unit based on an output of the contact pressure sensor after the mold is closed.
The mold pressure applying unit applies a pressing force from the outside to the slide core,
2. The optical product molding apparatus according to claim 1, wherein when the slide core is pushed back by a resin pressure, the control unit increases the pressing force applied to the slide core by the mold pressure applying unit.
The mold pressure applying unit includes a first actuator that supports the slide core and adjusts a position, and a second actuator that applies a pressing force to the slide core from the outside.
The controller adjusts the position of the slide core by the first actuator based on the output of the contact pressure sensor after mold closing, and when the slide core is pushed back by resin pressure, The apparatus for molding an optical product according to claim 2, wherein a pressing force applied to the slide core by a second actuator is increased.
4. The optical product molding apparatus according to claim 3, wherein the first actuator adjusts a contact pressure at the contact surface of the slide core by expansion and contraction.
The apparatus for molding an optical product according to claim 4, wherein the first actuator includes a piezoelectric element.
The optical product molding apparatus according to any one of claims 3 to 5, wherein the second actuator includes a pressure applying mechanism using hydraulic pressure or pneumatic pressure.
The control unit applies a pressing force to the slide core with a correction amount coarser than a pressure adjustment range executed by the first actuator according to an output of the contact pressure sensor by the second actuator. 7. A molding apparatus for optical products according to any one of items 1 to 6.
The control unit includes the first actuator so that the contact pressure on 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 when the mold is closed in the molding process. The apparatus for molding an optical product according to any one of claims 3 to 7, wherein the position of the slide core is feedback-controlled by the above.
The control unit applies a pressing force applied to the slide core by the second actuator when a contact pressure on the contact surface of the slide core is lower than a predetermined value at the time of resin injection and holding pressure in a molding process. The position of the slide core is increased by the first actuator so that the contact pressure at the contact surface of the slide core reaches 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 3 to 8, wherein the feedback control is performed.
The controller controls the first 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 during cooling of the molding process. The optical product molding apparatus according to any one of claims 3 to 9, wherein the position of the slide 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 between the slide cores, and the mold pressure applying unit determines the position of each slide core. The apparatus for molding an optical product according to any one of claims 1 to 10, which is adjusted.
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 mold pressure applying unit for adjusting the position of the slide core An optical product molding method using a molding apparatus comprising:
An optical product manufacturing method for adjusting a contact pressure of the contact surface of the slide core by adjusting a position of the slide core by the mold pressure applying unit based on an output of the contact pressure sensor after the mold is closed.