JP2007090851A - Press-forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To conduct approximately uniform transfer forming to a workpiece in press-forming even in the case wherein the workpiece has a variation of board thickness and flatness. <P>SOLUTION: An approximately rectangular parallelepiped elastic article 21 is attached to a portion from a central part to a circumferential edge part of an undersurface (bottom surface) of an upper die set 19. The elastic article 21 absorbs a tilt of the workpiece 35 during pressing the workpiece 35 by cooperation of an upper frame body 300 with a lower frame body 100, and thus, the elastic article 21 is composed of an elastic material such as urethane rubber, nitrile rubber, silicone rubber or fluororubber. For example the elastic article 21 has a thickness of 30 mm and shore hardness of 90. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a press molding apparatus for transferring a desired pattern onto the surface of a workpiece between an upper mold and a lower mold in cooperation with an upper mold and a lower mold.

  Conventionally, with respect to press molding of a light guide plate that performs pressurization and transfer using a transfer plate to a substantially rectangular thermoplastic resin plate, it is possible to shorten the molding cycle and to a thermoplastic resin plate There has been proposed a light guide plate press molding method and apparatus for the purpose of performing uniform pressurization and transfer with a relatively simple structure.

  In the apparatus according to the above proposal, the temperature control is performed during one molding cycle in which both the first die on the bed side and the second die on the upper movable platen side are provided with a flat plate cooling plate and the cooling platen. And a stamper provided on the surface side of the resistance heating plate, that is, a transfer plate. In addition to the above parts, a hydraulic cylinder for separating the resistance heating plate from the cooling plate, a stamper and the resistance heating plate, and a resistance heating plate and the cooling plate, respectively, A plurality of insulators are also provided for electrically insulating between the resistance heating plate and between the resistance heating plate and the cooling plate. The stamper is heated by a resistance heating plate and directly pressurizes the thermoplastic resin plate to perform transfer molding (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2004-0774769

  In the light guide plate press molding method and apparatus according to the above proposal, it is said that good transfer is possible by using at least one of the plurality of insulators as an elastic body. Certainly, according to the above proposal, it may be possible to absorb the unevenness of the thermoplastic resin plate that is the workpiece. However, the plurality of insulators are mainly intended for electrical insulation between the resistance heating plate to be energized and the stamper, and between the resistance heating plate and the cooling plate. That is, the place where the insulator is inserted is limited to the upper and lower surfaces (that is, the front surface side and the back surface side) of the resistance heating plate.

  By the way, in the hot press molding in which the fine pattern is transferred onto the surface of the thermoplastic resin plate using a stamper having a fine pattern, the height of the unevenness of the transferred pattern is several μm to several tens of μm. . On the other hand, the plate thickness of the thermoplastic resin plate that is the workpiece has a variation of about ± 0.1 mm, and further, the thickness and flatness of the mold to which the stamper is attached, and the stamper's own plate. There is also a variation of about 0.01 to 0.05 mm in thickness and flatness.

  Therefore, at the time of transfer molding of the thermoplastic resin sheet, the molding surface pressure varies on the contact surface between the stamper and the thermoplastic resin sheet (which is the workpiece), and the workpiece (the thermoplastic material) There arises a problem that a portion where the above pattern is not sufficiently transferred is formed on the surface of the resin plate-like body. Under such circumstances, it can be said that it is difficult to absorb the inclination in the above proposal when the plate thickness of the thermoplastic resin plate-like body that is a workpiece has an inclination. In particular, in so-called multi-cavity molding, in which a large number of transfer moldings are performed at a time, in addition to variations in plate thickness and flatness within each workpiece (thermoplastic resin plate), each workpiece Due to the large variation in the plate thickness between the two, there is a problem in that the stamper is in contact with the surface of the work material, and hence good transfer molding cannot be performed.

  Accordingly, an object of the present invention is to enable transfer molding to be performed substantially uniformly on a workpiece even when the plate thickness and flatness of the workpiece vary in press molding. is there.

  In addition, another object of the present invention is to provide a plurality of workpieces in press molding in which transfer molding is performed simultaneously, in addition to variations in plate thickness and flatness within each workpiece, each workpiece. Even when there is variation in the plate thickness between the materials, the object is to make it possible to perform transfer molding substantially uniformly on the workpieces.

  In the press molding apparatus according to the first aspect of the present invention, the upper mold and the lower mold cooperate to form a desired pattern on the surface of the workpiece between the upper mold and the lower mold. A stamper having a desired transfer pattern, which is to be transferred and is attached to the upper mold and / or the lower mold in a state where surface contact is possible with the surface of the workpiece, and the upper mold And an elastic member for absorbing variations in the thickness of the workpiece when the transfer pattern of the stamper is pressure-transferred to the surface of the workpiece on at least one of the lower molds, Is provided.

  In a preferred embodiment according to the first aspect of the present invention, the stamper is brought into surface contact with a temperature adjustment mechanism attached to the upper mold and / or the lower mold, and a predetermined temperature is set by the temperature adjustment mechanism. The desired transfer pattern is pressure-transferred onto the surface of the workpiece while being heated.

  In an embodiment different from the above, the stamper is made of nickel or SUS.

  In an embodiment different from the above, the upper mold is supported by a plurality of mutually independent drive shafts and a plurality of mutually independent drive mechanisms so as to be movable in the vertical direction.

  In an embodiment different from the above, the upper mold is in a state in which the loads on the drive shafts are substantially equal during the pressure transfer of the transfer pattern of the stamper to the workpiece. The downward movement is controlled through each of the drive mechanisms.

  In an embodiment different from the above, the elastic member is made of a material having a Shore hardness of about 90.

  In an embodiment different from the above, the elastic member is made of any one material of urethane rubber, nitrile rubber, silicone rubber, and fluorine rubber.

  In an embodiment different from the above, at least a heat insulating member is interposed between the temperature adjusting mechanism and the elastic member.

  Moreover, in embodiment different from the above, the said heat insulation member is comprised with the epoxy resin.

  Furthermore, in an embodiment different from the above, the stamper and the elastic member are integrally formed, and the integrally formed member made of the same material as the stamper is used as the temperature adjusting mechanism. It is adhered to a plate-like member for mounting and fixing to.

  In the press molding apparatus according to the second aspect of the present invention, the upper mold and the lower mold cooperate to form a desired pattern on the surface of the workpiece between the upper mold and the lower mold. A stamper having a desired transfer pattern, which is to be transferred and is attached to the upper mold and / or the lower mold in a state where surface contact is possible with the surface of the workpiece, and the upper mold And an elastic member for absorbing variations in the thickness of the workpiece when the transfer pattern of the stamper is pressure-transferred to the surface of the workpiece on at least one of the lower molds, A plurality of molding stages are provided, and each of the molding stages is supported by a plurality of independent drive systems so as to be movable in the vertical direction.

  In a preferred embodiment according to the second aspect of the present invention, the plurality of drive systems each include a drive shaft directly connected to the upper mold and a drive mechanism for driving the drive shaft.

  In an embodiment different from the above, the upper mold is configured so that the load applied to each of the drive shafts is substantially equal during the pressure transfer of the transfer pattern of the stamper to the workpiece at each molding stage. In this state, the downward movement is controlled through each of the drive mechanisms.

  In the press molding apparatus according to the third aspect of the present invention, the upper mold and the lower mold cooperate to form a desired pattern on the surface of the workpiece between the upper mold and the lower mold. A stamper having a desired transfer pattern, which is to be transferred and is attached to the upper mold and / or the lower mold in a state where surface contact is possible with the surface of the workpiece, and the upper mold And an elastic member for absorbing variations in the thickness of the workpiece when the transfer pattern of the stamper is pressure-transferred to the surface of the workpiece on at least one of the lower molds, And the size and shape of the upper / lower surface of the elastic member are substantially the same as the size and shape of the upper / lower surface of the workpiece.

  According to the present invention, even when there is variation in the plate thickness or flatness of a workpiece in press molding, it is possible to perform transfer molding on the workpiece substantially uniformly. .

  Further, according to the present invention, in press molding in which transfer molding is simultaneously performed on a plurality of workpieces, in addition to variations in plate thickness and flatness within each workpiece, Even when there are variations in the plate thickness, it is possible to perform transfer molding on these workpieces substantially uniformly.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of a press molding apparatus according to an embodiment of the present invention.

  This press molding apparatus performs hot press molding using a stamper having a fine pattern made of a metal such as nickel on an acrylic plate, which is a workpiece, for example, to provide a light guide plate for a backlight of a liquid crystal display. An optical component having a fine pattern on the surface, such as a diffuser plate, a lens, and an optical disk substrate, and a high-design panel are created. In hot press molding, the above-described light guide plate and the like are created by press-molding a heated stamper on an acrylic plate to transfer and pattern the pattern onto the acrylic plate.

  The press molding apparatus shown in FIG. 1 drives an upper frame 300 that is opposed to a lower frame 100 that is fixed to the ground or the like and that is movably supported in a vertical (up / down) direction. This is a so-called biaxial type in which two drive shafts are provided in total (indicated by reference numerals 37 and 39), one on each side. The lower frame body 100 and the upper frame body 300 both have a substantially rectangular parallelepiped shape as a whole.

  The lower frame 100 includes a bolster 1, a lower die set 3, a plate 5, a heat insulating plate 7, a temperature adjustment plate (hereinafter referred to as “temperature control plate”) 9, a stamper 11, a vacuum chamber 13, and a vacuum packing. 15 is included. On the other hand, the upper frame 300 described above includes the slide 17, the upper die set 19, the elastic body 21, the spacer 23, the heat insulating plate 25, the temperature control plate 27, the stamper 29, the vacuum chamber 31, and the vacuum packing 33. The plate 5, the heat insulating plate 7, the temperature control plate 9, the stamper 11, the elastic body 21, the spacer 23, the heat insulating plate 25, the temperature control plate 27, and the stamper 29 constitute a molding stage.

  In the lower frame 100, the bolster 1 has a substantially rectangular parallelepiped shape, and is attached and fixed to the upper part of a bed (not shown). A lower die set 3 having a substantially rectangular parallelepiped shape is attached and fixed from a central portion to a peripheral portion of the upper surface of the bolster 1. A vacuum chamber 13 is attached and fixed to the peripheral edge of the upper surface of the lower die set 3. The vacuum chamber 13 is provided at the peripheral edge of the upper surface of the lower die set 3 so that the shape seen from above has a square shape, and the upper end of the vacuum chamber 13 is subjected to pressure applied from the vertical direction. A vacuum packing 15 that can be expanded and contracted in the vertical direction is provided so that the shape viewed from above exhibits a square shape.

  In addition, a plate 5 having a substantially rectangular parallelepiped shape is attached and fixed from the center portion to the peripheral portion of the upper surface of the lower die set 3. A rectangular heat insulating plate 7 having a substantially flat plate shape is formed on the upper surface of the plate 5, a temperature adjusting plate 9 having a substantially rectangular parallelepiped shape is formed on the upper surface of the heat insulating plate 7, and an upper surface of the temperature adjusting plate 9 is A rectangular stamper 11 having a substantially flat plate shape is attached and fixed in a laminated manner.

  The plate 5 is made of a rigid material. The heat insulating plate 7 is provided to block the heat of the temperature control plate 9 from being conducted to the plate 5 side. For the heat insulating plate 7, for example, one made of an epoxy resin is used. The temperature control plate 9 is for heating / cooling the stamper 11, and a temperature control fluid hole 9 a for flowing a temperature control fluid (ie, gas or liquid) is provided in the temperature control plate 9. It has been.

  As described above, a fine pattern is formed on the stamper 11, and the workpiece (that is, acrylic) placed on the upper surface of the stamper 11 by the downward movement (downward movement) of the upper frame body 300. When the plate 35 is pressed against the stamper 29 of the upper frame 300 and is pressed from the upper surface side, the fine pattern is transferred to the bottom surface of the workpiece 35. At the same time, the fine pattern of the stamper 29 is also transferred to the upper surface (surface) of the workpiece 35. As will be described later in detail, the transfer of each pattern to the workpiece 35 is brought into close contact with the vacuum packing 15 in a state where the vacuum packing 33 of the upper frame 300 is in pressure contact with the downward movement of the upper frame 300. The space defined by the vacuum chamber 13 and the vacuum chamber 31 of the upper frame 300 is a sealed space, and the sealed space is evacuated.

  The workpiece 35 has a non-uniform thickness. That is, as shown in FIG. 1, the workpiece 35 has the largest thickness on the right end side in FIG. 1, the smallest thickness on the left end side in FIG. 1, and from the right end side in FIG. It is inclined to the left end side.

  In the upper frame 300, the slide 17 is movable in the vertical (up / down) direction by a slide drive mechanism (not shown) located above the slide 17 via the two left and right drive shafts 37 and 39 described above. Supported by When the slide 17 is moved in the vertical direction by a slide drive mechanism (not shown), the slide 17 is controlled in parallel with an accuracy of, for example, about ± 10 μm. The slide drive mechanism (not shown) includes, for example, two three-phase press drive AC servo motors (hereinafter simply referred to as “press AC servo motors”) (not shown here; the same applies hereinafter). Is built-in. The rotary shaft of each press AC servomotor and the drive shafts 37 and 39 are directly connected to each other via, for example, a ball screw mechanism (not shown).

  An upper die set 19 having a substantially rectangular parallelepiped shape is attached and fixed from the center portion to the peripheral portion of the lower surface (bottom surface) of the slide 17. A vacuum chamber 31 is attached and fixed to the peripheral edge of the lower surface (bottom surface) of the upper die set 19. The vacuum chamber 31 is provided at the peripheral edge of the lower surface of the upper die set 19 so that the shape viewed from below is a square shape, and the lower end of the vacuum chamber 31 is subjected to pressure applied from the vertical direction. A vacuum packing 33 that can be expanded and contracted in the vertical direction is provided so that the shape viewed from below is a square shape.

  Further, an elastic body 21 having a substantially rectangular parallelepiped shape is attached and fixed from the center portion to the peripheral portion of the lower surface (bottom surface) of the upper die set 19. A rectangular spacer 23 having a substantially flat plate shape is formed on the lower surface of the elastic body 21, and a rectangular heat insulating plate 25 having a substantially flat plate shape is formed on the lower surface of the spacer 23. The temperature control plate 27 having a substantially rectangular parallelepiped shape is attached to the lower surface of the temperature control plate 27 by a rectangular stamper 29 having a substantially flat plate shape.

  The elastic body 21 is for absorbing the inclination of the workpiece 35 when the workpiece 35 is pressurized by the cooperation of the upper frame 300 and the lower frame 100. For example, a material made of an elastic material such as urethane rubber, nitrile rubber, silicone rubber, or fluorine rubber capable of elastic recovery against repeated loads is employed. As the elastic body 21, one having a thickness of, for example, 30 mm and a Shore hardness of 90 is used.

  The spacer 23 is made of a rigid material because it is necessary to prevent the heat insulating plate 25 and the temperature control plate 27 from being distorted when the workpiece 35 is pressurized. The spacer 23 is provided with a cooling fluid flow path 23a for flowing a cooling fluid (that is, gas or water (cooling water)). By flowing a cooling fluid such as cooling water through the cooling fluid flow path 23a, the workpiece 35 is pressurized by the upper frame body 300 and the lower frame body 100 by the downward movement of the upper frame body 300, for example. In such a case, the elastic body 21 is prevented from being overheated.

  The heat insulating plate 25 is provided to block the heat of the temperature control plate 27 from being conducted to the spacer 23 side. As the heat insulating plate 25, for example, one made of an epoxy resin is used. The temperature control plate 27 is for heating / cooling the stamper 29. Inside the temperature control plate 27, a temperature control fluid hole 27a for supplying a temperature control fluid (ie, gas or liquid) is provided. It has been. Similarly to the stamper 11, a fine pattern is formed on the stamper 29, and the stamper (of the lower frame body 100) is heated by the temperature control plate 27 and the upper frame body 300 is moved downward (downward movement). 11 is pressed from the upper surface side. As a result, the fine pattern is transferred to the upper surface of the workpiece 35, and at the same time, the fine pattern of the stamper 11 is also transferred to the lower surface (bottom surface) of the workpiece 35.

  As already described, the transfer of each pattern to the workpiece 35 is performed in close contact with the vacuum packing 33 and the vacuum packing 15 of the lower frame 100 by the downward movement of the upper frame 300. The space defined by the vacuum chamber 31 and the vacuum chamber 13 of the lower frame 100 is a sealed space, and the sealed space is in a vacuum state.

  FIG. 2 is a diagram showing a state when the work material 35 is transfer-molded with the fine pattern of the stampers 11 and 29 by the press molding apparatus shown in FIG.

  As shown in FIG. 2, in order to press-transfer the upper surface side and the lower surface side of the workpiece 35 with the heated stampers 29 and 11, respectively, as described above, the vacuum packings 15 and 33 are brought into close contact with each other. The sealed space formed by the vacuum packings 15 and 33 and the vacuum chambers 13 and 31 needs to be kept in a vacuum state (using a vacuum pump or the like). The sealed space is formed by outputting a control signal for lowering the slide 17 from the control unit (not shown) to the two press AC servomotors (not shown here). This is done by the slide 17 moving downward via the drive shafts 37 and 39.

  When the sealed space is in a vacuum state, the two press AC servo motors are driven by the further output of the control signal for moving the slide 17 downward from the control unit, and the drive shafts 37, The slide 17 moves downward through 39 and contracts while the vacuum packings 15 and 33 are in pressure contact with each other. At the same time, pressure is applied to the workpiece 35 from above and below via the stampers 29 and 11. At this time, the inclination of the workpiece 35 in the left direction (in FIG. 2) is an elastic body according to the inclination. 21 is absorbed by contraction, the stampers 29 and 11 are in pressure contact (contact) with the workpiece 35 (upper / lower surface) substantially uniformly.

  Therefore, the fine patterns held by the stampers 29 and 11 are pressed and transferred substantially uniformly on the upper / lower surface of the workpiece 35.

  By the way, in the press molding apparatus having the above-described configuration, a control unit (not shown) constantly applies pressure to the workpiece 35 based on an output signal from a pressure detection sensor (load monitoring device) (not shown) or the like. While checking, each of the press AC servo motors is controlled to move the slide 17 downward toward a preset bottom dead center position. Then, when it is determined by the output signal from the pressure detection sensor that a preset pressure has been reached, the control unit controls each press AC servo motor to stop the downward movement of the slide 17. The position where it was stopped is regarded as the bottom dead center.

  Thus, since it is possible to always check the pressure applied to the workpiece 35 by the load monitoring device, when it is detected that the pressure applied to the workpiece 35 has reached the set pressure. Thus, it is possible to realize control for stopping the downward movement of the slide 17. However, there is a time lag between the time when it is detected that the applied pressure has reached the set pressure and the time when the downward movement of the slide 17 actually stops. For this reason, at the position where the downward movement of the slide 17 is stopped, a pressure value (load) exceeding the preset pressure value is output, so that the pressure exceeding the set value is not applied to the workpiece 39. In order to do so, it is necessary to slow down the slide 17. As a result of experiments conducted by the present inventors, it has been found that the downward movement speed of the slide 17 must be set to be considerably slow. Therefore, in the method of reducing the downward movement speed of the slide 17, the work efficiency is low. There is a problem of getting worse.

  In addition, the thickness of the workpiece 35 (which is an acrylic plate) changes due to heating and cooling. That is, in the process in which the heated stampers 29 and 11 are pressed against the workpiece 35 and pressurize the workpiece 35, the workpiece 35 increases the plate thickness due to thermal expansion and pushes up the slide 17. To do. On the other hand, the control unit performs control to increase the current value supplied to each of the press servomotors in an attempt to hold the stop position of the slide 17 at the positioned position. The pressure applied to exceeds the set pressure value. Next, after the transfer of the fine patterns of the stampers 29 and 11 to the upper / lower surfaces of the workpiece 35 is completed, the process proceeds to a cooling process for fixing the transfer. , The thickness of the workpiece 35 is reduced by contraction.

  Therefore, when the control for continuously holding the stop position of the slide 17 is performed, the pressure applied to the workpiece 35 from the slide 35 is thereby reduced.

  Thus, in order to always apply a constant pressure from the slide 17 to the workpiece 35, the bottom dead center of the slide 17 once determined follows the change in the thickness of the workpiece 35. However, it is difficult to realize the following control operation only by the position control operation in the upward / downward direction of the slide 17.

  Accordingly, the present inventors have proposed a press forming apparatus including a control system having a configuration as shown in FIG.

  FIG. 3 is a block diagram showing the configuration of a control system provided in the press molding apparatus according to one embodiment of the present invention.

  The control system includes a movement command unit 43, a command counter 45, a comparator 47, a deviation counter 49, a pressure control unit 51, a displacement counter 53, and a servo amplifier 55 including a current limiter 57 included in the NC device 41. , A linear encoder 59, and an AC servo motor for press (abbreviated as “motor” in FIG. 3) 61.

  In the NC device 41, the movement command unit 43 receives the closed position data (in the vertical direction) of the vacuum chambers 31 and 13 of the slide 17 and the bottom dead center through an operation unit (not shown) of the NC device 41 from the operator. The position data (in the vertical direction) and the position data (in the vertical direction) of the top dead center are input. Based on the input position data, the movement command signal to the closed position of the vacuum chambers 31 and 13 of the slide 17, the movement command signal to the position of the bottom dead center, and the movement command to the position of the top dead center. Signals are generated, and the generated movement command signals are output to the command counter 45 as appropriate.

  The command counter 45 inputs each of the movement command signals output from the movement command unit 43. Then, a number of rectangular wave pulse signals corresponding to the input movement command signal are generated, and the generated plurality of rectangular wave pulse signals are output to the comparator 47 as a pulse train, that is, as slide target position data. For example, when a command signal indicating that the slide 17 should be moved to the closed position of the vacuum chambers 31 and 13 is output from the movement command unit 43, the current position (for example, top dead center) of the slide 17 in the vertical direction is output. The command counter 45 generates a number of rectangular wave pulse signals corresponding to the moving distance of the slide 17 to the position where the vacuum chambers 31 and 13 are closed. When a command signal indicating that the slide 17 should be moved to the bottom dead center position is output from the movement command unit 43 or when a command signal indicating that the slide 17 should be moved to the top dead center position is output. In the command counter 45, the same processing as described above is performed.

  The pressure control unit 51 includes a pressure / motor current table 63. The pressure / motor current table 63 is set corresponding to a plurality of pressure value data (unit t) applied to the workpiece 35 from the slide 17 and those pressure value data necessary to generate these pressures. A plurality of motor current value data (indicating a current value supplied from the power source to the press AC servomotor 61) (unit A). For example, when an applied pressure setting value is input from an operator through an operation unit (not shown) of the NC device 41, the applied pressure control unit 51 refers to the pressure / motor current table 63 and a motor corresponding to the applied pressure setting value. Current value data is read from the pressure / motor current table 63. The read motor current value data is output to a current limiter 57 built in the servo amplifier 55 as upper limit value data of the motor current supplied from the power source to the motor 61. For example, when an applied pressure setting value of 40 t is input from the operator through the operation unit (not shown) of the NC device 41, the applied pressure control unit 51 corresponds to the pressure value data 40 (t) from the pressure / motor current table 63. 60 (A) is read out as motor current value data to be output, and the 60 (A) is output to the current limiter 57 as upper limit value data of the motor current.

  The comparator 47 receives the above-described slide target position data output from the command counter 45 and the slide current position data output from the displacement counter 53 as a pulse train of (a plurality of) rectangular wave pulse signals. The difference between the two is calculated. Then, a pulse train of a rectangular pulse signal indicating the difference is output to the deviation counter 49 as position deviation data of the slide 17. There is a time difference between the motor drive command signal output to the servo amplifier 55 from the deviation counter 49 constituting the NC device 41 together with the comparator 47 and the actual moving speed of the slide 17 driven by the motor 61. (Time lag). Therefore, when the slide 17 is moving (in the vertical direction), the comparison is performed in the comparator 47, and as a result, the slide target position data from the command counter 45 and the slide from the displacement counter 53 output from the comparator 47 are compared. The deviation from the current position data is constantly monitored by the deviation counter 49.

  The deviation counter 49 preliminarily stores upper limit value data of a position deviation for assuming that the movement (in the vertical direction) of the slide 17 is stopped. The deviation counter 49 counts and accumulates the position deviation data output (as a rectangular wave pulse train) from the comparator 47, and converts the number of rectangular wave pulse signal pulse trains corresponding to the counted position deviation data to the motor. A drive command signal is output to the servo amplifier 55. The deviation counter 49 appropriately compares the accumulated position deviation data with the built-in position deviation upper limit value data, and when the position deviation data exceeds the position deviation upper limit value data as a result of the comparison. Then, the output of the motor drive command signal to the servo amplifier 55 is stopped. As a result, the driving of the motor 61 is stopped, and the downward movement of the slide 17 is stopped.

  When position deviation data indicating further downward movement of the slide 17 remains in the deviation counter 49 when the downward movement of the slide 17 is stopped, the stop position of the slide 17 (the stamper 29 and The deviation counter 49 resets the position deviation data so that the further downward movement distance of the slide 17 from the pressure contact position with the workpiece 35 is substantially zero. As a result, the deviation data indicating that the slide 17 remaining in the deviation counter 49 should be moved down is substantially zero, so that sudden acceleration that occurs when the slide 17 is moved up can be suppressed, and mechanical shock caused by the sudden acceleration can be suppressed. Occurrence can be regulated.

  The servo amplifier 55 incorporates a current limiter 63 for making the drive current of the motor 61 supplied from the power source to the motor 61 through the servo amplifier 55 equal to or less than a predetermined value. As the servo amplifier 55, for example, an AC servo amplifier is employed. The servo amplifier 55 is based on the motor drive command signal output from the deviation counter 49 and the upper limit value data of the motor drive current output from the pressure controller 51 to the current limiter 57 (in the vertical direction of the slide 17). ) The motor 61 is driven so that no positional deviation occurs during the movement. However, when the value of the motor drive current supplied from the power supply is about to exceed the current limit value (60A in this embodiment) set in the current limiter 57, the value of the motor drive current is Limited to the current limit value or less.

  Although the motor 61 has already been described, an AC servo motor that can rotate forward / reversely is used.

  In the present embodiment, a linear encoder 59 is used to measure the movement distance (in the vertical direction) of the slide 17. The linear encoder 59 generates one rectangular wave pulse signal per preset unit moving distance of the slide 17, and the generated rectangular wave pulse signal is displaced as a displacement pulse (in the vertical direction) of the slide 17. Output to the counter 53. This displacement pulse indicates the current position of the moving slide 17 (in the vertical direction).

  The displacement counter 53 counts and accumulates the displacement pulses output from the linear encoder 59 (as a rectangular wave pulse train), and stores a pulse train of rectangular wave pulse signals corresponding to the counted displacement pulses into the current slide position. The data is output to the comparator 47.

  FIG. 4 is an explanatory diagram showing the transition of the target position (in the vertical direction) of the slide 17 and the change in the pressure applied from the slide 17 to the workpiece 35 by the control system shown in FIG.

  In FIG. 4A, the vertical axis represents the position (in the vertical direction) of the slide 17, and the horizontal axis represents time. A curve 65 shows the transition of the target position (in the vertical direction) of the slide 17. On the other hand, in FIG. 4B, the vertical axis represents the magnitude of the applied pressure from the slide 17 to the workpiece 35, and the horizontal axis represents time.

In FIG. 4A, the slide 17 is shown by a curve 65 at t ₁ after a predetermined time has elapsed since the motor drive command signal for moving the slide 17 downward is output from the NC device 41 to the servo amplifier 55. As shown, the vacuum chambers 31 and 13 rapidly descend to a position where they are closed. Then, at t ₂ when the slide 17 reaches the position where the vacuum chambers 31 and 13 are closed, the lowering operation of the slide 17 is temporarily stopped, and then toward the position of the bottom dead center set in advance at t ₃ A rapid descent is started again.

Next, when the slide 17 continues the rapid lowering operation as it is, a position (t where the slide 17 may collide with the workpiece 35 due to the inertial force acting on the slide 17 and damage the workpiece 35 or the like (t ₄ ), control is performed to reduce the lowering speed of the slide 17 in order to weaken the inertial force. In the present embodiment, 60 A is set as upper limit value data of the motor current from the pressure control unit 51 (of the NC device 41) shown in FIG. 3 to the current limiter 57 (of the servo amplifier 55). The upper limit value of the pressure applied to the workpiece 35 is 40t.

Therefore, in a state where a current of 60 A is supplied as a motor drive current from the power source through the servo amplifier 55, the slide 17 is lowered at a position where the work material 35 contacting the slide 17 is applied with a pressure of 40 t from the slide 17. The operation will stop. In this embodiment, in FIG. 4A, the position indicated by the alternate long and short dash line 67 is the position where the slide 17 stops the lowering operation, that is, the slide where the work material 35 is applied with a pressure of 40 t by the slide 17. 17 stop positions. As is apparent with reference to FIGS. 4A and 4B, the time during which the workpiece 35 is applied with the pressure of 40 t by the slide 17 is from time t ₅ to time t ₈ . Between.

  When the slide 17 stops the lowering operation, the NC device 41 assumes that the slide 17 has reached the bottom dead center (position).

  Here, it is determined that the deviation between the current position data of the slide 17 output from the linear encoder 59 to the NC device 41 and the slide target position data (that is, position deviation data) exceeds the upper limit value data. In this case, as described with reference to FIG. 3, the NC device 41 executes a process for making the deviation substantially zero.

When pressurization of the workpiece 35 by the slide 17 is completed (t ₈ ), the motor 61 rotates in the direction opposite to that when the slide 17 is lowered by the motor drive command signal from the NC device 41 to the servo amplifier 55. , the slide 17 starts to rise operation, returns to the top dead center (the position of) at time t _9.

  FIG. 5 is a flowchart showing the control operation of the control system shown in FIG.

  In FIG. 5, first, a command to lower the slide 17 to the lower limit position (bottom dead center position) (of the slide 17) is output from the NC device 41 to the servo amplifier 55 (step S71). Next, the deviation counter 49 compares the position deviation upper limit value data incorporated in advance with the position deviation data given through the comparator 47, and whether the position deviation data exceeds the position deviation upper limit value data. A check is made (step S72). If the position deviation data exceeds the upper limit value data of the position deviation as a result of this check (YES in step S72), the slide 17 from when it was first determined that the position deviation data exceeded the upper limit value data of the position deviation. The time for pressurizing the workpiece 35 is measured (step S73).

  Next, it is checked whether or not the duration of pressing the workpiece 35 by the slide 17 has reached a preset pressing time (step S74). As a result of this check, if it is determined that the pressurization duration has reached a preset pressurization time (YES in step S74), the deviation counter 49 is cleared (step S75), and the NC device 41 causes the slide 17 to Is output to the servo amplifier 55 (step S76).

  As described above, according to one embodiment of the present invention, variations in thickness of the workpiece 35, stampers 11, 29, (metal mold), etc. are absorbed, and the transfer surfaces of the stampers 11, 29 and the workpiece are processed. It is possible to make the contact state between the front and back surfaces of the acrylic plate 35, which is a material, substantially uniform. Accordingly, in order to make the contact state substantially uniform, the heating temperature of the stamper (11, 29) is increased more than necessary to pressurize the workpiece (35) more than necessary or to increase the surface temperature of the workpiece (35). Since it does not need to be raised, a fine pattern of the stampers 11 and 29 can be transferred to the workpiece 35 with a small molding surface pressure and a low heating temperature.

  Further, since the pattern can be transferred at a low heating temperature, the heating time of the stampers 11 and 29 is shortened, and the molding time is shortened. Further, since the workpiece 35 is not heated more than necessary and the entire workpiece 35 is not softened, transfer molding with a small molding surface pressure is possible. The swelling of the material can be kept small, and post-processing of the molded product can be shortened or omitted.

  Further, since the transfer can be performed with a small molding surface pressure, the equipment capacity of the press molding apparatus can be reduced, and the pattern can be transferred at a low heating temperature, so that the stampers 11 and 29 are heated. Therefore, it is possible to reduce the amount of heat required for this purpose and to reduce the running cost.

  FIG. 6 is a diagram showing an overall configuration of a press molding apparatus according to a modification of the embodiment of the present invention.

  In this modification, the lower frame 110 is provided with a thin elastic body 81 and a cooling fluid flow path 83a for flowing a cooling fluid instead of the plate 5 shown in FIG. The lower frame shown in FIG. 1 has a spacer 83 made of a rigid material, and a back plate 85 and an elastic body 87 are interposed between the stamper 11 and the temperature control plate 9. Different from 100. The upper frame 310 is different from the upper frame 300 shown in FIG. 1 in that a back plate 89 and an elastic body 91 are interposed between the temperature control plate 27 and the stamper 29. Since other configurations are the same as those shown in FIG. 1, in FIG. 6, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the lower frame 110, cooling water always flows as a cooling fluid in the cooling fluid passage 83 a of the spacer 83, and heat insulation that prevents the elastic body 81 from being overheated by this cooling water. Serves as a board. The elastic body 81 absorbs variations in the overall parallelism of the workpiece 36 when the fine pattern of the stampers 29 and 11 with respect to the workpiece 36 is transferred and molded. On the other hand, the elastic body 87 is made of a material having heat resistance, thermal conductivity, and elastic recovery against repeated loads. The elastic body 87 is integrated with the stamper 11 and the back plate 85 and functions together with the stamper 11 as a hot press stamper. The elastic body 87 and the stamper 11 absorb variations in local thickness of the stampers 29 and 11 and the workpiece 36 when the fine pattern of the stampers 29 and 11 on the workpiece 36 is transferred. As the elastic body 87, for example, one having a Shore hardness of 50 to 70 is used.

  In the upper frame 310, similarly to the elastic body 81, the elastic body 21 absorbs the variation in the overall parallelism of the work material 36 during the transfer molding of the fine pattern of the stampers 29 and 11 with respect to the work material 36. It is supposed to be. On the other hand, similarly to the elastic body 87, the elastic body 91 is made of a material having heat resistance, thermal conductivity, and an elastic recovery force against repeated loads. The elastic body 91 is also integrated with the stamper 29 and the back plate 89 and functions together with the stamper 29 as a stamper for heat press. The elastic body 91 and the stamper 29 absorb variations in local plate thickness of the stampers 29 and 11 and the workpiece 36 when the fine pattern of the stampers 29 and 11 on the workpiece 36 is transferred. The elastic body 91 having a Shore hardness of 50 to 70, for example, is used.

  As described above, the stampers 11 and 29 are made of a material such as nickel or SUS, but the back plates 85 and 89 are also thermally expanded / contracted when the stampers 11 and 29 are heated / cooled. It is desirable to select the same material as the stampers 11 and 29 in consideration of the above. As the elastic bodies 87 and 91, it is desirable to use those made of heat-dissipating silicone rubber having particularly good thermal conductivity. Further, the thicknesses of the stampers 11 and 29, the back plates 85 and 89, and the elastic bodies 87 and 91 are each preferably about 0.2 to 0.5 mm.

  FIG. 7 is a perspective view showing a mounting structure of the stamper 11, the elastic body 87, and the back plate 85 of the lower frame 110 shown in FIG.

  The laminated structure of the stamper 11, the elastic body 87, and the back plate 85 shown in FIG. The elastic body 87 is formed by pouring (coating) the rubber so as to have a uniform thickness and curing. Separately, the stamper 11 and the elastic body 87 are integrated by adhering a sheet-like elastic body 87 to one surface (which becomes the back surface) of the stamper 11 with an adhesive or a double-sided tape, and then the back plate. The above laminated structure can also be realized by bonding to 85 (the upper surface). The back plate 85 is fixed to the upper surface of the temperature control plate 9 by, for example, vacuum suction. It is also possible to fix the back plate 85 to the upper surface of the temperature control plate 9 using a method other than vacuum suction, for example, an adhesive tape or the like.

  According to this modification, since the stamper 11, the elastic body 87, and the back plate 85 are integrated, the stamper 11 and the elastic body 87 are attached to, removed from the temperature control plate 9, and positioning at the time of attachment. Can be done easily.

  FIG. 8 is a perspective view showing a modified example of the attachment structure of the stamper 11, the elastic body 87, and the back plate 85 of the lower frame 110 shown in FIG. 7.

  In the mounting structure shown in FIG. 8, the back plate is slightly larger than the back plate 85 as shown by reference numeral 86, and the back plate 86 is temperature-controlled by a fastener 88 such as a bolt or a screw. 9 is different from the mounting structure shown in FIG. Since other configurations are the same as those of the mounting structure shown in FIG. 7, detailed description thereof will be omitted. 7 and 8 may be applied to the structure for attaching the stamper 29, the elastic body 91, and the back plate 89 of the upper frame 310 shown in FIG.

  FIG. 9 is a diagram showing an overall configuration of a press molding apparatus according to another embodiment of the present invention.

  The press molding apparatus shown in FIG. 9 makes it possible to perform transfer molding on a plurality of workpieces at a time with a single press molding apparatus. That is, on the upper surface of the lower die set 121 having the same configuration as the lower die set 3 shown in FIG. 1, the plate having the same configuration as the plate 5, the heat insulating plate 7, the temperature control plate 9, and the stamper 11 shown in FIG. A plurality of heat insulating plates, temperature control plates, and stampers are provided (in FIG. 9, two for convenience of illustration and explanation). On the other hand, on the lower surface of the upper die set 123 having the same configuration as the upper die set 19 shown in FIG. 1, the same as the elastic body 21, the spacer 23, the heat insulating plate 25, the temperature control plate 27, and the stamper 29 shown in FIG. A plurality of elastic bodies, spacers, heat insulating plates, temperature control plates, and stampers each having the structure (2 in FIG. 9 for convenience of illustration and description) are provided.

  The forming stage A is constituted by the plate 125, the heat insulating plate 127, the temperature adjusting plate 129, the stamper 131, the elastic body 133, the spacer 135, the heat insulating plate 137, the temperature adjusting plate 139, and the stamper 141. Similarly, the forming stage B is configured by the plate 143, the heat insulating plate 145, the temperature adjusting plate 147, the stamper 149, the elastic body 151, the spacer 153, the heat insulating plate 155, the temperature adjusting plate 157, and the stamper 159.

  Since other parts are the same as those shown in FIG. 1, in FIG. 9, the same parts as those shown in FIG.

  Of the plurality of workpieces 161 and 163 (for convenience of illustration and description in FIG. 9), the workpiece 161 is placed on the stamper 131 on the molding stage A side, and the workpiece 163 is Each of the workpieces 161 and 163 is transferred and molded independently of each other on the stamper 149 on the molding stage B side.

  The slide 17 is provided for each of the plurality of molding stages (A, B) provided in the press molding apparatus of FIG. 9 (two in FIG. 9) (in FIG. 9, 2) points. The movement of the slide 17 (in the vertical direction) is performed by a plurality of (in this embodiment, two) independent drive systems (for example, the aforementioned AC servo amplifier and the AC servo for press) linked to each of the above points. Including the motor). Then, when the fine patterns of the stampers 131, 141, 149, 159 with respect to the workpieces 161, 163 are transferred and molded, the above drive systems are controlled by the control unit so that the loads applied to the respective points are substantially the same. The movement of the slide 17 (in the vertical direction) is performed.

  FIG. 10 is a diagram illustrating a state in which a fine pattern of a stamper is transferred and molded on the workpiece by the press molding apparatus illustrated in FIG. 9.

  As described with reference to FIG. 2, the vacuum packings 15, 33 are used to individually press and transfer the upper and lower surfaces of the workpieces 161, 163 by the heated stampers 131, 141, 149, 159, respectively. It is necessary to keep the sealed space formed by the vacuum packings 15 and 33 and the vacuum chambers 13 and 31 in a vacuum state due to the close contact therebetween.

  When the sealed space is in a vacuum state, the slide 17 is moved downward through the respective points, and the vacuum packings 15 and 33 are contracted in a pressed state, and the stampers 131, 141, and 149 are respectively applied to the workpieces 161 and 163 from above and below. 159, pressure is applied. At this time, the inclination of the work material 161 in the right direction (in FIG. 10) is absorbed by the elastic body 133 contracting in accordance with the inclination, while the work material 163 is moved in the left direction (in FIG. 10). Is absorbed by the elastic body 151 contracting in accordance with the inclination. Therefore, the stampers 131, 141, 149, and 159 are brought into pressure contact (contact) with the workpieces 161 and 163 (upper / lower surfaces) substantially uniformly.

  Therefore, the fine patterns of the stampers 131, 141, 149, and 159 are pressed and transferred substantially uniformly on the upper and lower surfaces of the workpieces 161 and 163, respectively.

  As described above, according to the press molding apparatus according to another embodiment of the present invention, in the press molding apparatus having the configuration shown in FIG. 9, the workpieces having different thickness variations depending on the molding stages A and B, respectively. 161 and 163, or when there is a relative difference in thickness between the workpieces 161 and 163, the load applied to the points A and B corresponding to the molding stages A and B is mutually Since the movement of the slide 17 (in the vertical direction) is controlled so as to be substantially the same by an independent drive system, the slide 17 is on the molding stage A side where the workpiece 161 having a relatively small plate thickness exists. Pressurization is performed in an inclined state. However, variations in the thickness of the workpieces 161 and 163 and the inclination of the slide 17 due to the variations are absorbed by the elastic body 133 on the molding stage A side and the elastic body 151 on the molding stage B side, and the thickness variation. Since substantially uniform molding surface pressure can be applied to the transfer surfaces of the workpieces 161 and 163 having different values, good transfer molding can be performed.

  Further, the heating temperature of the stampers (131, 141, 149, 159) is increased more than necessary in order to pressurize the workpieces (161, 163) with a load larger than necessary or to increase the surface temperature of the workpieces (161, 163). Since good transfer can be performed without raising, the energy consumption can be reduced, the running cost can be reduced, and the life of the mold or the like can be extended. Furthermore, the equipment cost can be reduced.

FIG. 11 is an explanatory diagram showing a modification of the transition of the target position (in the vertical direction) of the slide by the control system shown in FIG. 3 and the change in the pressure applied from the slide to the workpiece.

In the example shown in FIG. 11, as shown in FIG. 11B, the pressure applied to the workpiece 35 via the slide 17 is set in, for example, three stages of 20 t, 30 t, and 40 t. For this reason, in FIG. 11A, the curve indicating the target position (in the vertical direction) of the slide 17 denoted by reference numeral 171 is also abrupt after the slide 17 reaches the position where the vacuum chambers 31 and 13 are closed. After the slope is reached, the slope is set to be gentler than that shown in FIG. That is, when the slide 17 continues the rapid lowering operation as it is, a position (t ′) where the slide 17 may collide with the workpiece 35 due to the inertial force acting on the slide 17 and damage the workpiece 35 or the like. ₄ ), the lowering speed of the slide 17 is controlled so that the lowering position of the slide 17 moves gently and the pressure applied to the workpiece 35 is reduced in order to weaken the inertial force. It is gradually increased. The other contents are the same as the contents described with reference to FIG.

  As in the case shown in FIG. 4, when the slide 17 stops the lowering operation, the NC device 41 assumes that the slide 17 has reached the bottom dead center (position).

  If it is determined that the deviation between the current position data of the slide 17 and the slide target position data (that is, the set position of the bottom dead center) exceeds the upper limit value data, the deviation is The NC device 41 executes a process for making it substantially zero.

  FIG. 12 is a flowchart showing a modification of the control operation of the control system shown in FIG.

  In FIG. 12, the processing operations shown in steps S181 to S183 are the same as the processing operations shown in steps S71 to S73 of FIG. 5, and thus detailed description thereof is omitted.

In step S73, from the start of counting pressurization duration of the workpiece 35 by the slide 17, (in the present embodiment, 20t) pressurizing value 1 in the pressing time (the embodiment in, T ₁ ) Is timed up (step S184). The result of this check, when the pressing time T ₁ is is determined that the time is up (YES at step S184), changes the setting of the pressurizing value against the workpiece 35 by the slide 17, from pressurization value 1 to the pressurization value 2 (Step S185). Next, it is checked whether or not the pressurization time at the pressurization value 2 (T _{2 in} this embodiment) is up (step S186).

The result of this check, when the pressing time T ₂ is determined that the time is up (YES at step S186), changes the setting of the pressurizing value against the workpiece 35 by the slide 17, the pressurization value 2 to pressurization value 3 (Step S187). Next, it is checked whether or not the pressurization time at the pressurization value 3 (T _{3 in} this embodiment) is up (step S188). The result of this check, when the pressing time _{T 3} is determined that the time is up (Step S188 YES), as well as clear the deviation counter 49 (step S189), NC device 41, the position of the top dead center (the slide 17 ) Is output to the servo amplifier 55 (step S190).

Incidentally, if the pressing time T ₁ is determined not to be time-up (NO at step S184), if the pressing time T ₂ is determined to not timed (NO at step S186), and pressing time in the case where T ₃ is determined to not timed (nO at step S188), the process proceeds to operation both shown in step S181.

  Even in the above-described modification, substantially the same effect as that in the embodiment of the present invention shown in FIGS. 3 to 5 can be obtained.

  By the way, in general, planar materials such as the workpiece (acrylic plate) 35 shown in FIG. 1 and the workpiece (acrylic plate) 36 shown in FIG. 6, for example, as shown in FIG. 1 and FIG. When pressure is applied using a flat metal mold, a local increase in molding surface pressure occurs at the outer edge of the flat material. As already described, the stamper (11, 29) having a fine pattern is pressed against the surface of a thermoplastic resin plate (planar material) such as an acrylic plate (35, 36) at a predetermined temperature and a predetermined pressure. In the hot press molding in which a fine pattern is transferred to the surface of the thermoplastic resin plate, the stamper (11, 29) is attached to a temperature adjustment plate (9, 27), that is, a flat mold having a temperature adjustment function. And press against the thermoplastic resin plate.

  At this time, since the molding surface pressure at the outer edge portion of the planar material (acrylic plates 35, 36) which is a thermoplastic resin plate is stronger than the inner portion of the planar material, at the central portion of the thermoplastic resin plate, There is a possibility that the molding surface pressure is relatively insufficient, and that a fine pattern of the stamper (11, 29) is not completely transferred onto the thermoplastic resin plate. On the other hand, since the molding surface pressure is strong at the outer edge portion of the thermoplastic resin plate, the side surface of the thermoplastic resin plate swells greatly. If the workpiece is a light guide plate as described above, the side surface of the molded product is a light incident surface, and the side surface must be flat, so that it swells to the side surface of the workpiece by hot press molding. If this occurs, post-processing is required to finish the side surface flat, thereby increasing the number of manufacturing steps.

  In addition, in order to eliminate the incomplete transfer of the fine pattern at the central portion of the thermoplastic resin plate described above, the pressing force of the press must be increased.

  Therefore, the present inventors suppress increase in local molding surface pressure generated at the outer edge of the workpiece, and absorb variations in the machining accuracy of the workpiece and the mold to the workpiece. As a means for equalizing the applied surface pressure, an arrangement has been conceived in which an elastic body having substantially the same shape as the pressing surface of a workpiece is inserted into a mold for attaching a stamper. The elastic body (substantially the same shape as the pressure surface of the workpiece) can be elastically recovered even when a load is repeatedly applied, for example, composed of materials such as urethane rubber, nitrile rubber, silicone rubber, and fluorine rubber Is adopted.

  The elastic body may be disposed directly under a planar mold that pressurizes the workpiece, or may have a structure in which a heat insulating material, a spacer, or the like is interposed between the planar mold and the elastic body. Furthermore, the elastic body may be disposed in both the upper and lower molds, or may be disposed in only one of the upper and lower molds.

  FIG. 13 is a diagram showing an overall configuration of a press molding apparatus according to still another embodiment of the present invention.

  The press molding apparatus according to the embodiment shown in FIG. 13 uses a so-called uniaxial drive shaft 211 instead of the so-called biaxial drive shaft (37, 39) shown in FIG. 1 is different from the press forming apparatus according to the embodiment of the present invention shown in FIG. 1 in that the lower cooling plate 213 is used instead of the thick plate 5 shown in FIG. Further, the press forming apparatus according to the above embodiment is substantially the same size and the same as the upper / lower surface of the workpiece 215 instead of the elastic body 21 having the upper surface and the lower surface of the size and shape shown in FIG. Also in the point which uses the upper elastic body 217 which has a shape upper surface and a lower surface, it differs from the press molding apparatus which concerns on one Embodiment of this invention shown in FIG. The lower cooling plate 213 is formed with a cooling fluid channel 213a for flowing a cooling fluid (that is, gas or water (cooling water)).

  Furthermore, the press molding apparatus according to the above embodiment includes a lower elastic body 219 having an upper surface and a lower surface that are substantially the same size and shape as the upper / lower surface of the workpiece 215, the lower die set 3 and the lower cooling plate 213. Is different from the press molding apparatus according to the embodiment of the present invention shown in FIG. In the above embodiment, the workpiece 215 having a substantially uniform plate thickness as shown in FIG. 13 is used as the workpiece instead of the workpiece 35 having a non-uniform thickness as shown in FIG. Used.

  It is desirable that the upper / lower surface (vertical / horizontal) dimensions of the upper elastic body 217 and the lower elastic body 219 be approximately 10 mm larger than the upper / lower surface (vertical / horizontal) dimensions of the workpiece 215.

  In the configuration other than the above, the same components as those shown in FIG. 1 are denoted by the same reference numerals and their detailed description is omitted.

  According to the above-described embodiment, when the workpiece 215 is processed, it is possible to prevent an increase in local molding surface pressure at the outer edge portion of the workpiece 215, and the workpiece, stamper, mold, and the like can be prevented. By absorbing variations in the thickness dimension, it is possible to make the molding surface pressure of the stamper transfer surface and the surface of the workpiece uniform, and it is possible to transfer the pattern with a small pressure and low heating temperature. it can.

  In addition, since the pattern can be transferred at a low heating temperature, the heating time of the stamper is shortened and the molding time is shortened. In addition to not heating the workpiece more than necessary to soften the entire workpiece, transfer molding with a small pressure is possible, so the material bulges on the side of the workpiece during transfer molding Can be kept small, and post-processing of the molded product can be shortened or omitted.

  Furthermore, since it is possible to transfer with a small pressure, it is possible to reduce the equipment capacity of the press and to heat at a low heating temperature, so the amount of heat required to heat the stamper is reduced. Running costs can also be reduced.

  In the above embodiment, the workpiece 215 having a substantially uniform thickness as shown in FIG. 13 is taken as an example of the workpiece, but the workpiece having a non-uniform thickness as shown in FIG. The above embodiment can be applied to (35), and the same effect as in the workpiece 215 having a substantially uniform plate thickness can be obtained.

  FIG. 14 is a diagram showing an overall configuration of a press molding apparatus according to a modification of the embodiment shown in FIG.

  The press molding apparatus according to the modification shown in FIG. 14 is a rigid spacer having an upper / lower surface having the same size and shape as the upper / lower surface of the lower cooling plate 213, instead of the lower elastic body 219 shown in FIG. 221 is different from the press molding apparatus according to the embodiment shown in FIG. 13 in that 221 is used. In the configuration other than the above, the same components as those shown in FIG. 13 are denoted by the same reference numerals, and detailed description thereof is omitted.

  Also in the modified example, the same effect as in the embodiment shown in FIG. 13 can be obtained. In the above embodiment, the workpiece 215 having a substantially uniform thickness as shown in FIG. 13 is taken as an example of the workpiece, but the workpiece having a non-uniform thickness as shown in FIG. The above embodiment can be applied to (35), and the same effect as in the workpiece 215 having a substantially uniform plate thickness can be obtained. In the above modification, the workpiece 215 having a substantially uniform thickness as shown in FIG. 14 is taken as an example of the workpiece, but the workpiece having a non-uniform thickness as shown in FIG. The modified example can be applied to the processed material (35), and the same effect as in the processed material 215 having a substantially uniform plate thickness can be obtained.

  FIGS. 15 and 16 are generated on pressure-sensitive paper when an acrylic flat plate of 350 mm × 280 mm × t8 mm, which is a workpiece, is pressed at 600 KN using a mold having the configuration shown in FIG. It is the figure which showed distribution of the pressurization surface pressure by black shading. FIG. 15 shows a case where the upper elastic body (urethane sheet having a Shore hardness of 90) 217 shown in FIG. 14 has a size of 450 mm × 420 mm × thickness 25 mm, which is larger than the pressure surface of the acrylic plate as the workpiece. The pressure surface pressure distribution on the pressure sensitive paper is shown. Further, FIG. 16 shows the distribution of the pressing surface pressure on the pressure sensitive paper when the size of the upper elastic body (217) is 350 mm × 280 mm × thickness 25 mm which is the same as that of the acrylic plate (217) as the workpiece. Show.

  The pressure-sensitive paper having the pressure surface pressure distribution shown in FIG. 15 and FIG. 16 is obtained by placing and pressing on an acrylic plate as a workpiece. In FIGS. 15 and 16, the dark black portion is a portion to which a strong pressing surface pressure is applied. FIG. 16 is compared with FIG. Whereas the pressing surface pressure is applied to the upper / lower surface substantially uniformly, it is clear that in FIG. 15, the pressing surface pressure applied to the upper / lower surface of the workpiece has large unevenness. is there.

  That is, as shown in FIG. 15, when the upper / lower surface dimension of the upper elastic body (urethane rubber) (217) is larger than the upper / lower surface dimension of the acrylic plate as the workpiece, the acrylic plate The pressing surface pressure at the outer edge portion of the plate is locally increased, so that the pressing surface pressure on the surface of the acrylic plate becomes non-uniform. On the other hand, as shown in FIG. 16, the upper elastic body (that is urethane rubber) (217) having the same size of the upper / lower surface of the acrylic plate as the workpiece and the upper / lower surface is used. In this case, the distribution of the pressing surface pressure on the surface of the acrylic plate becomes substantially uniform.

  The preferred embodiments of the present invention and modifications thereof have been described above, but these are examples for explaining the present invention, and the scope of the present invention is limited to these embodiments and modifications thereof. It is not meant to be limited only. The present invention can be implemented in various other forms.

The figure which shows the whole structure of the press molding apparatus which concerns on one Embodiment of this invention. The figure which shows the state at the time of carrying out the transfer molding of the fine pattern which a workpiece has which a stamper has with the press molding apparatus described in FIG. The block diagram which shows the structure of the control system with which the press molding apparatus which concerns on one Embodiment of this invention is provided. Explanatory drawing which shows the transition of the target position (in the vertical direction) of the slide by the control system described in FIG. 3, and the change of the pressure applied to a workpiece from a slide. 4 is a flowchart showing a control operation of the control system shown in FIG. 3. The figure which shows the whole structure of the press molding apparatus which concerns on the modification of one Embodiment of this invention. The perspective view which shows the attachment structure of the stamper of the lower frame body of FIG. 6, an elastic body, and a backplate. The perspective view which shows the modification of the attachment structure of the stamper of the lower side frame body described in FIG. 7, an elastic body, and a backplate. The figure which shows the whole structure of the press molding apparatus which concerns on other embodiment of this invention. The figure which shows the state at the time of the transfer material of the fine pattern which a workpiece has a stamper by the press molding apparatus described in FIG. Explanatory drawing which shows the modification of the change of the target position (in the vertical direction) of the slide by the control system described in FIG. 3, and the change of the pressure applied to a workpiece from a slide. 6 is a flowchart showing a modification of the control operation of the control system shown in FIG. 3. The figure which shows the whole structure of the press molding apparatus which concerns on further another embodiment of this invention. The figure which shows the whole structure of the press molding apparatus which concerns on the modification of embodiment shown in FIG. The figure which shows distribution of the pressurization surface pressure which arises on a pressure sensitive paper, when the acrylic board which is a workpiece is pressurized by predetermined pressure using the metal mold | die shown in FIG. The figure which shows distribution of the pressurization surface pressure which arises on a pressure sensitive paper, when the acrylic board which is a workpiece is pressurized by predetermined pressure using the metal mold | die shown in FIG.

Explanation of symbols

1 Bolster 3 Lower die set 5 Plate 7, 25 Heat insulation plate 9, 27 Temperature adjustment plate (temperature control plate)
11, 29 Stamper 13, 31 Vacuum chamber 15, 33 Vacuum packing 17 Slide 19 Upper die set 21 Elastic body 23 Spacer 35 Work material (acrylic plate)
37, 39 Drive shaft 41 NC device 43 Movement command section 45 Command counter 47 Comparator 49 Deviation counter 51 Pressure control section 53 Displacement counter 55 Servo amplifier 57 Current limiter 59 Linear encoder 61 AC motor (motor) for press
63 Pressure / motor current table 100 Lower frame 300 Upper frame

Claims (14)

In a press molding apparatus for transferring a desired pattern on the surface of a workpiece between the upper mold and the lower mold in cooperation with the upper mold and the lower mold,
A stamper having a desired transfer pattern, which is attached to the upper mold and / or the lower mold in a state where surface contact is possible with the surface of the workpiece;
When the transfer pattern of the stamper is pressure-transferred to the surface of the workpiece on at least one of the upper mold and the lower mold, the thickness variation of the workpiece is absorbed. An elastic member;
A press molding apparatus comprising: The press molding apparatus according to claim 1, wherein
In a state where the stamper is in surface contact with a temperature adjustment mechanism attached to the upper mold and / or the lower mold and heated to a predetermined temperature by the temperature adjustment mechanism, the desired transfer pattern is Press molding equipment that is pressure-transferred onto the surface of the workpiece. The press molding apparatus according to claim 1, wherein
A press molding apparatus in which the stamper is made of nickel or SUS. The press molding apparatus according to claim 1, wherein
A press molding apparatus in which the upper die is supported by a plurality of independent drive shafts and a plurality of independent drive mechanisms so as to be movable in the vertical direction. The press molding apparatus according to claim 4, wherein
The upper mold moves downward through the drive mechanisms in a state where the loads on the drive shafts are substantially equal during the pressure transfer of the transfer pattern of the stamper to the workpiece. Is a press-forming device that is controlled. The press molding apparatus according to claim 1, wherein
A press molding apparatus in which the elastic member is made of a material having a Shore hardness of about 90. The press molding apparatus according to claim 6, wherein
A press molding apparatus in which the elastic member is made of any one of urethane rubber, nitrile rubber, silicone rubber, and fluorine rubber. In the press molding apparatus of Claim 2,
A press molding apparatus in which at least a heat insulating member is interposed between the temperature adjusting mechanism and the elastic member. The press molding apparatus according to claim 8, wherein
A press molding apparatus in which the heat insulating member is made of an epoxy resin. The press molding apparatus according to claim 1, wherein
The stamper and the elastic member are integrally formed, and are bonded to a plate-like member made of the same material as the stamper for attaching and fixing the integrally formed member to the temperature adjusting mechanism. Press forming equipment. In a press molding apparatus for transferring a desired pattern on the surface of a workpiece between the upper mold and the lower mold in cooperation with the upper mold and the lower mold,
A stamper having a desired transfer pattern, which is attached to the upper mold and / or the lower mold in a state where surface contact is possible with the surface of the workpiece;
When the transfer pattern of the stamper is pressure-transferred to the surface of the workpiece on at least one of the upper mold and the lower mold, the thickness variation of the workpiece is absorbed. An elastic member;
A plurality of molding stages having
Each of the molding stages is
A press molding apparatus in which each is supported by a plurality of independent drive systems so as to be movable in the vertical direction. The press molding apparatus according to claim 11, wherein
A press molding apparatus in which the plurality of drive systems each include a drive shaft directly connected to the upper mold and a drive mechanism for driving the drive shaft. In the press molding apparatus according to claim 11 or 12,
The upper mold passes through each drive mechanism in a state in which the load applied to each drive shaft is substantially equal during the pressure transfer of the transfer pattern of the stamper to the workpiece in each molding stage. A press molding device in which the downward movement is controlled. In a press molding apparatus for transferring a desired pattern on the surface of a workpiece between the upper mold and the lower mold in cooperation with the upper mold and the lower mold,
A stamper having a desired transfer pattern, which is attached to the upper mold and / or the lower mold in a state where surface contact is possible with the surface of the workpiece;
When the transfer pattern of the stamper is pressure-transferred to the surface of the workpiece on at least one of the upper mold and the lower mold, the thickness variation of the workpiece is absorbed. An elastic member;
With
The press molding apparatus in which the size and shape of the upper / lower surface of the elastic member are substantially the same as the size and shape of the upper / lower surface of the workpiece.

Images