JP6581619B2 - Molding apparatus and molding method - Google Patents

Description

  The present invention relates to a technique for molding a fiber reinforced resin, and particularly to a technique for molding a fiber reinforced resin by press molding.

  In recent years, carbon fiber reinforced resin (CFRP) has attracted attention as a lightweight and high strength material. Among them, carbon fiber reinforced thermoplastic resin (CFRTP) using a thermoplastic resin as a matrix material has excellent mechanical properties and does not require heating for a long time, thereby shortening cycle time such as press molding. Therefore, it is expected as a material that makes it possible to form a high-strength member at low cost.

  However, if the temperature of the CFRTP material to be molded is lowered during the molding of the CFRTP material, the flowability of the matrix material is lowered and the movement of the carbon fibers is inhibited. Thus, when the movement of the carbon fiber is inhibited, the moldability of the CFRTP material is drastically lowered, and it becomes difficult to mold the CFRTP material into a desired shape.

  In particular, when press molding is performed, if the mold temperature is set to a low temperature (below the melting point of the matrix material) in order to shorten the cycle time, the CFRTP material is rapidly cooled during the press molding process. It is difficult to maintain a good state.

  Therefore, when press molding is performed using a low-temperature mold, development of a technique for suppressing a decrease in the temperature of the CFRTP material and maintaining good moldability of the CFRTP material is underway. For example, in Non-Patent Document 1, when press molding is performed using a mold having a temperature of room temperature, the carbon fiber sheet is sandwiched with silicon rubber to suppress a decrease in the temperature of the carbon fiber sheet. Attempts are being made to improve.

Takeshi Yoneyama, 5 others, “Pressing of thermoplastic carbon fiber sheet”, Plasticity and processing (Journal of the Japan Society for Technology of Plasticity), Japan Society for Technology of Plasticity, Vol. 53, No. 613, p. 55-59

  However, even with the technique disclosed in Non-Patent Document 1, it is difficult to sufficiently suppress a decrease in formability when performing press molding using a low-temperature mold. Further, in Non-Patent Document 1, in order to improve moldability, the carbon fiber sheet is sandwiched with silicon rubber to suppress a decrease in the temperature of the carbon fiber sheet. It takes a long time to sufficiently decrease. Therefore, it is difficult to sufficiently shorten the cycle time. This problem is not limited to the molding of carbon fiber reinforced resins, but is common to the molding of fiber reinforced resins including glass fiber reinforced resins.

  The present invention has been made to solve the above-described conventional problems, and provides a technique for ensuring sufficient moldability while shortening the cycle time when molding a fiber reinforced resin. Objective.

In order to achieve at least a part of the above object, the present invention can be realized as the following forms or application examples.
A molding apparatus according to a first aspect of the present invention is a molding apparatus for molding a molding material of a fiber reinforced thermoplastic resin including a matrix material of thermoplastic resin and reinforcing fibers, and the molding material is used as the matrix material. A heating device for heating to a temperature higher than the melting point of the first mold, a first mold having projections and depressions, a second mold having projections and depressions corresponding to the projections and depressions of the first mold, A first mold is fixed, a ram defining a relative positional relationship between the first and second molds, a bolster on which the second mold is placed, and the ram above And a press device having a balancer for pushing up, wherein the bolster is fixed to the press device, and the balancer is driven by a tank for storing a working fluid and the working fluid Balance cylinder and The cylinder chamber, whose volume is reduced when the ram of the balance cylinder moves upward, is connected to the tank via a relief valve, and the temperatures of the first and second molds are: It is set below the melting point of the matrix material, and the pressing device sandwiches the molding material heated by the heating device between the first and second molds by driving the ram. And the ram is in the vicinity of the end position where the molding of the molding material is finished and on the molding start position side where the molding of the molding material is started. It is driven so that the terminal speed, which is the ram speed at the time when the ram reaches the position near the terminal, is 100 mm / s or more.
A molding apparatus according to a second aspect of the present invention is a molding apparatus for molding a molding material of a fiber reinforced thermoplastic resin including a matrix material of thermoplastic resin and reinforcing fibers, and the molding material is used as the matrix material. A heating device for heating to a temperature higher than the melting point of the first mold, a first mold having projections and depressions, a second mold having projections and depressions corresponding to the projections and depressions of the first mold, A press device having a ram that defines the relative positional relationship between the first and second molds, and the temperature of the first and second molds is set to be equal to or lower than the melting point of the matrix material. The press device drives the ram so that the material to be molded heated by the heating device is sandwiched between the first and second molds and the material to be molded is formed. The ram is configured to be molded The terminal speed, which is the ram speed at the time when the ram reaches the position near the terminal end on the molding start position side where the molding of the material to be molded is started, is near the terminal position where the molding of the material is finished is 100 mm / s or more And the ram has a first ram to which the first mold is fixed and a second ram to which the second mold is fixed, The pressing device drives the second ram so as to follow the movement of the first ram after the time when the ram reaches the end position by driving the first ram. And
According to the molding apparatuses of these first and second embodiments, the molding material is sandwiched between the first and second molds at the end of molding. Cools quickly. Therefore, it is possible to shorten the cycle time from when the heated workpiece is carried into the press device until the molded workpiece is taken out. In addition, by setting the termination speed to 100 mm / s or more, the temperature of the material to be molded can be maintained sufficiently high over almost the entire period from the molding start time to the molding end time, and it is necessary for molding. Time can be shortened. Therefore, when molding the molding material of fiber reinforced thermoplastic resin, it becomes possible to ensure sufficient moldability while shortening the cycle time. Furthermore, since the two molds are prevented from bouncing at the end of molding, the risk of damaging the molding material molded by the bouncing can be reduced.

[Application Example 1]
A molding apparatus for molding a molding material of a fiber reinforced thermoplastic resin including a matrix material of thermoplastic resin and reinforcing fibers, the heating apparatus heating the molding material to a temperature higher than the melting point of the matrix material A first mold in which irregularities are formed, a second mold in which irregularities corresponding to the irregularities in the first mold are formed, and a relative relationship between the first and second molds. A press device having a ram that defines a positional relationship, and the temperatures of the first and second molds are set to be equal to or lower than the melting point of the matrix material, and the press device drives the ram. By doing so, the molding material heated by the heating device is sandwiched between the first and second molds, and the molding material is molded. In the vicinity of the end position where the forming of the material ends. Wherein the end position near the molding start position side molding is started to be profiled, terminal velocity is ram speed at a point of time when the ram has reached is driven so that the 100 mm / s or higher Te, molding apparatus.

  According to this application example, since the material to be molded is sandwiched between the first and second molds at the end of molding, the material to be molded is quickly cooled after the molding is completed. Therefore, it is possible to shorten the cycle time from when the heated workpiece is carried into the press device until the molded workpiece is taken out. In addition, by setting the termination speed to 100 mm / s or more, the temperature of the material to be molded can be maintained sufficiently high over almost the entire period from the molding start time to the molding end time, and it is necessary for molding. Time can be shortened. Therefore, when molding the molding material of fiber reinforced thermoplastic resin, it becomes possible to ensure sufficient moldability while shortening the cycle time.

[Application Example 2]
The molding apparatus according to application example 1, wherein the ram is driven such that a ram speed at the molding start position is not more than twice the terminal speed.

  By setting the ram speed at the molding start position to be equal to or less than twice the terminal speed, it is possible to suppress a decrease in moldability at the molding start time.

[Application Example 3]
The molding apparatus according to Application Example 1 or 2, wherein a distance between the end vicinity position and the end position is 1/5 or less of a distance between the molding start position and the end position.

  By setting the distance between the end vicinity position and the end position to 1/5 or less of the distance between the molding start position and the end position, the temperature of the molding material can be more reliably maintained.

[Application Example 4]
4. The molding apparatus according to any one of application examples 1 to 3, wherein the press device further includes a bolster fixed to the press device, and the first mold is fixed to the ram. The molding device, wherein the second mold is placed on the bolster via a cushion.

  By placing the second mold on the bolster via the cushion, it is possible to prevent the two molds from bouncing at the end of molding even when the terminal speed is sufficiently high. Therefore, the possibility of damaging the material to be molded formed by the bounce can be reduced.

[Application Example 5]
The molding apparatus according to any one of Application Examples 1 to 3, wherein the press apparatus further includes a bolster fixed to the press apparatus, and a balancer for pushing the ram upward. The first mold is fixed to the ram, the second mold is placed on the bolster, and the balancer is driven by a tank that stores a working fluid and the working fluid. A forming cylinder, wherein the tank is connected via a relief valve from a cylinder chamber whose volume is reduced when the ram of the balance cylinder moves upward.

  Also according to this application example, since the two molds are prevented from bouncing at the end of molding, it is possible to reduce the possibility of damaging the molding material molded by the bouncing.

[Application Example 6]
4. The molding apparatus according to any one of application examples 1 to 3, wherein the ram includes a first ram to which the first mold is fixed and a second ram to which the second mold is fixed. And the pressing device drives the first ram to move the second ram to the movement of the first ram after the ram reaches the end position. Molding device that drives to follow.

  Also according to this application example, since the two molds are prevented from bouncing at the end of molding, it is possible to reduce the possibility of damaging the molding material molded by the bouncing.

[Application Example 7]
7. The molding apparatus according to any one of application examples 1 to 6, wherein the press apparatus is a screw press apparatus that is a servo screw press apparatus that drives a ram by a servo motor.

  By using a servo screw press device as the press device, it becomes easier to set the terminal speed to 100 mm / s or more.

  Note that the present invention can be realized in various modes. For example, a molding apparatus for molding a fiber-reinforced thermoplastic resin molding material, a molding method for molding a fiber-reinforced thermoplastic resin molding material, and production of a fiber-reinforced thermoplastic resin molded article using these apparatuses and methods The present invention can be realized in the form of a method or a control device or a control method of a press device for realizing those devices and methods.

Explanatory drawing which shows the shaping | molding process of CFRTP as 1st Embodiment of this invention. Explanatory drawing which shows the structure of a press apparatus. It is sectional drawing which shows the structure of a metal mold | die. Explanatory drawing which shows operation | movement of the metal mold | die at the time of shape | molding a prepreg. The block diagram which shows the structure of the drive control function of a servomotor. The graph which shows an example of the operating condition of the press apparatus at the time of shape | molding CFRTP. The graph which shows the operation state of the press apparatus in the formation process of CFRTP. The graph which shows the result of having evaluated the behavior change of the ram by the presence or absence of a cushion. The graph which shows the result of having evaluated the behavior change of the ram by the presence or absence of a cushion. The graph which shows the actual measurement result of forming speed and terminal speed. The graph which shows the mode of the temperature change of the test material during shaping | molding. The graph which shows the mode of the temperature change of the test material during shaping | molding. The graph which shows the mode of the temperature change of the test material during shaping | molding. The photograph which shows the external appearance evaluation result of a molded article. Explanatory drawing which shows the position which performed evaluation of the void amount in a molded article. The photograph which shows the mode of the cross section of the area | region which evaluated void amount. The photograph which shows the mode of the cross section of the area | region which evaluated void amount. The photograph which shows the mode of the cross section of the area | region which evaluated void amount. The hydraulic circuit diagram which shows the structure of the hydraulic circuit connected to a balance cylinder. Explanatory drawing which shows the structure of the press apparatus in 3rd Embodiment. The block diagram which shows the structure of the drive control function of the servomotor in 3rd Embodiment. Explanatory drawing which shows an example of operation | movement of the press apparatus in 3rd Embodiment.

Hereinafter, modes for carrying out the present invention will be described in the following order.
A. First embodiment:
A1. CFRTP molding process:
A2. Configuration of press machine:
A3. Mold configuration and operation:
A4. Press machine operation:
A5. Example:
B. Second embodiment:
C. Third embodiment:
D. Variation:

A. First embodiment:
A1. CFRTP molding process:
FIG. 1 is an explanatory diagram showing a carbon fiber reinforced thermoplastic resin (CFRTP) molding process (hereinafter also simply referred to as “molding process”) as a first embodiment of the present invention. In this molding process, the press machine 100 is used to deep-draw the CFRTP prepreg PPG to be molded. In addition, in FIG. 1, it draws so that vertical upper direction may become the upper direction of a paper surface. Accordingly, the vertical direction of the paper surface is the vertical direction, and the horizontal direction of the paper surface is the horizontal direction. Similarly, in the following, unless otherwise specified, the vertical direction and the horizontal direction are expressed as the vertical direction and the horizontal direction of the paper. In the following description, the vertically upward and vertically downward directions are also simply referred to as “upward” and “downward”.

  In the molding step shown in FIG. 1, first, a CFRTP prepreg (hereinafter also simply referred to as “prepreg”) PPG to be molded is prepared. The prepreg PPG is a plate-like material obtained by laminating a plurality of CFRTP sheets (hereinafter also simply referred to as “sheets”) obtained by impregnating a carbon fiber fabric obtained by weaving carbon fiber yarns, which are reinforcing fibers, with a matrix material. Various thermoplastic resins can be used as the matrix material. As the matrix material, for example, polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, acrylonitrile butadiene styrene, polymethyl methacrylate, polyether ether ketone, polyurethane, or polyamide (nylon) can be used.

  As shown in FIG. 1A, the prepared prepreg PPG is carried into a heating device 910. The prepreg PPG is carried into the heating device 910 using, for example, an automatic conveyance device. In the heating device 910, the prepreg PPG is heated to a temperature exceeding the melting point of the matrix material. The heating temperature is set to, for example, a temperature 50 to 70 ° C. higher than the melting point in consideration of a decrease in temperature in the molding process.

  The heated prepreg PPG is carried out of the heating device 910 and carried into the press device 100. Carrying out the prepreg PPG from the heating device 910 and carrying it in to the press device 100 can be performed using an automatic conveyance device. As shown in FIG. 1B, the prepreg PPG carried into the press apparatus 100 is a bolster of the press apparatus 100 via an upper mold 200 that is a mold attached to the ram 120 of the press apparatus 100 and a cushion 390. It is arranged between the lower mold 300 which is a mold placed on the 130. The cushion 390 disposed between the bolster 130 and the lower mold 300 is configured by arranging a plurality of cylindrical urethane rubbers. Although details will be described later, in the example of FIG. 1, a screw press device (servo screw press device) that controls the raising and lowering of the ram 120 by a servo motor 153 attached to the frame 110 is used as the press device 100. . The specific configurations of the upper mold 200 and the lower mold 300 will also be described later.

  After the prepreg PPG is disposed between the upper die 200 and the lower die 300, the ram 120 is lowered by driving the servo motor 153 of the press device 100. When the ram 120 is lowered to a predetermined position (lower end), the prepreg PPG is sandwiched between the upper mold 200 and the lower mold 300. As a result, the prepreg PPG is formed into a shape corresponding to the shape of the die provided on the upper die 200 and the punch provided on the lower die 300 (both not shown) as shown in FIG. Thus, a prepreg PPF molded into a desired shape is obtained. Since the lower end is a position where the molding of the prepreg PPG is completed and the molded prepreg PPF is obtained, it can also be called a “termination”.

  After the ram 120 is lowered to the lower end, the position of the ram 120 is held at the lower end while pressure is applied to the prepreg PPF until a preset time (holding time) elapses. The upper mold 200 and the lower mold 300 (hereinafter, also simply referred to as “mold”) have a temperature set below the melting point of the matrix material. Therefore, until the holding time elapses, the temperature of the prepreg PPF decreases and the molded prepreg PPF is cured. The prepreg PPF (molded product) molded into a desired shape and cured is taken out of the press device 100 by driving the servo motor 153 to raise the ram 120 after the holding time has elapsed. The temperature of the mold can be arbitrarily set as long as it is equal to or lower than the melting point of the matrix material, but is preferably set to 80 ° C. or lower. By controlling the temperature of the mold to 80 ° C. or less, the matrix material can be prevented from adhering to the mold, so that the molded product can be easily taken out, and cleaning of the mold can be omitted or the frequency of cleaning the mold can be reduced. Can be reduced. Furthermore, if the mold temperature is set to 80 ° C. or lower, the holding time can be shortened and the cycle time can be further shortened.

A2. Configuration of press machine:
FIG. 2 is an explanatory diagram showing the configuration of the press apparatus 100. In FIG. 2, the external appearance from the front of the press apparatus 100 is shown on the left side of the central axis indicated by the alternate long and short dash line, and a partial cross section of a part of the press apparatus 100 is shown on the right side. This partial cross section shows a state cut along a plane passing through the central axis and parallel to the front surface. As described above, the press apparatus 100 shown in FIG. 2 is a servo screw press apparatus using the servo motor 153 (see FIG. 1). In FIG. 2, the servo motor 153 is not shown for convenience.

  In addition to the frame 110, the ram 120, and the bolster 130 described above, the press device 100 includes a screw 140, a rotation drive unit 150, a slide guide 160, and a balancer 170.

  The frame 110 includes an outer shell plate 111 and an inner shell plate 112 extending in a vertical direction, a top plate 113 disposed on the upper surface of the outer shell plate 111 and the inner shell plate 112, a shaft fixing member 114, a thrust bearing 115, And a bushing 116. These members 111 to 116 are fixed to each other and constitute a so-called gate-type (bridge-type) frame. The inner shell plate 112 is provided with an opening 119 penetrating in the horizontal direction. A slide guide 160 extending in the vertical direction is fixed to the central axis side of the inner shell plate 112.

  The ram 120 has a ram main body 121 provided with a hole 129 along the central axis, and a female screw plate 122 fixed to the ram main body 121. The female screw plate 122 is a cylindrical member, and a female screw 128 is formed on the inner surface thereof. Further, the ram body 121 slides with respect to the slide guide 160 at its end. Accordingly, the ram 120 is restricted from rotating around the central axis and is movable in the vertical direction. The bolster 130 is fixed to the frame 110.

  The screw 140 is a member formed from a single bar, and is formed with a shaft 141, a large-diameter portion 142 having a larger outer diameter than the shaft 141, and a male screw 143 in this order from vertically above. In the press device 100, the shaft 141 is fixed to the thrust bearing 115 of the frame 110, and the upper surface of the large diameter portion 142 is in contact with the bushing 116 of the frame 110. Accordingly, the vertical movement of the screw 140 with respect to the frame 110 is restricted. Further, the male screw 143 provided on the screw 140 is meshed with the female screw 128 provided on the female screw plate 122 of the ram 120.

  The rotation drive unit 150 includes a pulley 151 and a toothed belt 152. The shaft 141 of the screw 140 is fitted in the center of the pulley 151. The toothed belt 152 is attached so as to span the pulley 151 shown in FIG. 2 and the servo motor 153 (FIG. 1). Therefore, by rotating the servo motor 153, the pulley 151 and the screw 140 rotate around the central axis. When the screw 140 rotates, the ram 120 having the female screw 128 meshed with the male screw 143 moves in the vertical direction in accordance with this rotation. Note that the movement of the ram 120 in the vertical direction by rotationally driving the servo motor 153 in this manner can be said to drive the ram 120 itself in the vertical direction.

  As described above, the ram 120 moves according to the rotation of the servo motor 153. Therefore, by controlling the rotation of the servo motor 153, the position and speed of the ram 120 and the pressure applied to the prepreg PPG during molding can be controlled. Such control of the press apparatus 100 will be described later.

  The upper mold 200 is attached to a ram 120 that moves relative to the frame 110, and the lower mold 300 is placed on a bolster 130 that is fixed to the frame 110. Therefore, it can be said that the relative positions of the two molds 200 and 300 are defined by the ram 120.

  The balancer 170 includes a balance cylinder 171, a cylinder rod 172 extending from the balance cylinder 171, and a connection arm 173 that connects the cylinder rod 172 and the ram 120 (ram body 121). By applying pressure from below the balance cylinder 171 using compressed air or the like, the cylinder rod 172 and the ram 120 are pushed up to balance these weights. As the cylinder rod 172 and the ram 120 are pushed up in this way, it is easier to control the raising and lowering of the ram 120 and a gap between the male screw 143 and the female screw 128 is suppressed.

A3. Mold configuration and operation:
FIG. 3 is a cross-sectional view showing the configuration of the molds 200 and 300. The upper mold 200 includes a base 210, a die 220, a die fixing unit 230, a blank holder 240, and a shim 250. These members 210 to 250 are fixed to each other, and the base 210 is attached to the ram 120 of the press device 100 as shown in FIG. The die 220 is provided with a recess 228 for molding the prepreg PPG and an air hole 229 for venting air from the recess 228 during molding. Corresponding to the air holes 229, the base 210 is also provided with air holes 218. The blank holder 240 is provided with a recess 249 at the periphery, and a shim 250 is attached to the recess 249. By adjusting the thickness of the shim 250, prepreg PPGs having different thicknesses can be formed.

  The lower mold 300 includes a base part 310, a punch 320, a liner 330, a blank holder 340, a spring pressing part 360, and a spring 370. Of these members 310 to 370, the punch 320 and the spring 370 are fixed to the base 310. The punch 320 is provided with a convex portion 321 for molding the prepreg PPG. On the top of the spring 370, the liner 330, the blank holder 340, and the spring pressing portion 360 are mounted in a state of being fixed to each other.

  The liner 330 and the blank holder 340 are provided with through holes 338 and 348 for passing the punch 320, respectively. Therefore, the liner 330, the blank holder 340, and the spring pressing part 360 are all movable in the vertical direction. Then, when the spring pressing portion 360 is pushed upward by the spring 370, the upper end of the convex portion 321 of the punch 320 is positioned below the upper surface of the blank holder 340 when no pressure is applied. Yes.

  Note that only the recess 228 is provided in the die 220 constituting the upper mold 200, and only the protrusion 321 corresponding to the shape of the recess 228 of the die 220 is provided in the punch 320 constituting the lower mold 300. . However, if the concave portion 229 is used as a reference, the lower surface of the die 220 has a convex shape, and if the convex portion 321 is used as a reference, the peripheral portion of the punch 320 has a concave shape. Therefore, if at least one concave portion 228 or convex portion 321 is provided as in the die 220 or the punch 320, it can be said that the die 220 or the punch 320 is formed with uneven portions having a corresponding shape.

  FIG. 4 is an explanatory diagram showing the operation of the molds 200 and 300 when molding the prepreg PPG. When the ram 120 is lowered from the state shown in FIG. 3 and the upper die 200 is lowered toward the lower die 300, as shown in FIG. 4A, the peripheral portion of the prepreg PPG is the upper die 200 and the lower die. 300 is sandwiched between respective blank holders 240 and 340. When the upper die 200 is further lowered from this state, as shown in FIG. 4B, the spring 370 contracts and the liner 330, the blank holder 340, and the spring pressing portion 360 of the lower die 300 are lowered. As a result, the upper end of the punch 320 reaches the position of the upper surface of the blank holder 340 and comes into contact with the prepreg PPG.

  At this time, pressure is applied from the blank holders 240 and 340 to the peripheral portion of the prepreg PPG. Therefore, since the peripheral edge part of the prepreg PPG is sandwiched and held (clamped) by the blank holders 240 and 340, generation of wrinkles in the prepreg PPG is suppressed by molding. Note that the pressure applied from the blank holders 240 and 340 to the peripheral edge of the prepreg PPG is given by the repulsive force of the spring 370. Therefore, the force for clamping the peripheral edge of the prepreg PPG by the blank holders 240 and 340 can be set to a desired strength by appropriately adjusting the spring constant of the spring 370.

  When the upper die 200 is further lowered from the state shown in FIG. 4B, the convex portion 321 (FIG. 3) of the punch 320 is pushed into the concave portion 228 of the die 220. When the ram 120 (FIG. 2) reaches the lower end, as shown in FIG. 4C, the prepreg PPF is sandwiched between the convex portion 321 of the punch 320 and the concave portion 228 of the die 220, and pressure is applied to the prepreg PPF. Join. Thereby, the shape of the formed prepreg PPF becomes a shape that follows the shape of the punch 320 and the die 220. In the first embodiment, no stopper is provided to prevent the convex portion 321 of the punch 320 from being pushed into the concave portion 228 of the die 220 from the state shown in FIG. It is also possible to provide such a stopper. Such a stopper is disposed between the upper mold 200 and the lower mold 300, or between the ram 120 and the bolster 130, for example.

  As shown in FIG. 4C, in the first embodiment, the molded prepreg PPF is in direct contact with the molds 200 and 300. As described above, the temperatures of the molds 200 and 300 are set to be equal to or lower than the melting point of the matrix material included in the prepreg PPF. Therefore, since the molded prepreg PPF is rapidly cooled, the holding time in which the prepreg PPF is held between the convex portion 321 of the punch 320 and the concave portion 228 of the die 220 can be shortened. In the first embodiment, the holding time can be shortened as described above, and therefore, the cycle time from when the heated prepreg PPG is carried into the press apparatus 100 until the molded prepreg PPF is taken out is shortened. Is possible.

A4. Servo motor drive control:
FIG. 5 is a block diagram showing the configuration of the drive control function of the servo motor 153. The control unit 10 that controls the press device 100 is realized as a computer that includes an interface that exchanges signals with the press device 100.

  The control unit 10 includes a drive condition determination unit 11, a speed detection unit 12, a position detection unit 13, and a torque detection unit 14 as functional units. Each of these functional units 11 to 14 is realized by a computer executing a program. The press device 100 includes a motor control unit 191 as a component related to control. In addition, the servo motor 153 is provided with an encoder 192 that measures the rotation state of the servo motor 153 as a component related to control.

  The speed detection unit 12 and the position detection unit 13 detect the rotation speed and rotation angle of the servo motor 153 based on the output signal from the encoder 192, respectively. The torque detector 14 detects the drive torque of the servo motor 153 based on the output signal of the motor controller 191. The drive condition determination unit 11 determines the drive condition of the servo motor 153 based on the rotation speed, rotation angle, and drive torque of the servo motor 153 detected as described above and the preset operation condition of the press device 100. .

  The motor control unit 191 supplies electric power to the servo motor 153 according to the drive condition of the servo motor 153 determined by the drive condition determination unit 11 to drive and control the servo motor 153. As the servo motor 153 is driven and controlled in this way, the rotation angle, rotation speed, and driving torque of the servo motor 153 are controlled. Then, the position and speed of the ram 120 (FIG. 1) corresponding to these and the pressure applied to the workpiece prepreg PPG, the lower mold 300, and the like are controlled according to the operating conditions of the press device 100.

  In the example of FIG. 5, the rotation angle, rotation speed, and driving torque of the servo motor 153 are detected as parameters corresponding to the position and speed of the ram 120 (FIG. 1) and the pressure applied to the prepreg. However, it is also possible to directly detect the position and velocity of the ram 120 and the pressure in addition to at least some of these. In this case, the press device 100 is provided with a linear encoder that detects the position of the ram 120 or a strain gauge that detects pressure.

A4. Press machine operation:
FIG. 6 is a graph showing an example of operating conditions of the press apparatus 100 when molding CFRTP. In FIG. 6, the horizontal axis represents time, the left vertical axis represents the position (ram displacement) of the ram 120 (FIG. 1), and the right vertical axis represents the lowering speed (ram lowering speed) of the ram 120. Note that the position of the ram 120 indicated by the left vertical axis in FIG. 6 is such that the vertically upward direction is the positive direction. Therefore, the ram displacement takes the minimum value P1 when the ram 120 reaches the lower end. The ram speed takes a maximum value Vx in a state where the descending speed of the ram 120 is maximized. The ram speed is usually expressed so that the driving direction of the ram 120 at the time of molding is a positive value. Therefore, in FIG. 6, the ram speed is a positive value below 0 and a negative value above 0.

  As shown in FIG. 6, in the period (acceleration period) from time 0 to T1, the ram 120 is accelerated vertically downward. In this acceleration period, the ram 120 is lowered from the upper end P0, and the ram speed becomes the maximum speed Vx at the time point T1 when the acceleration period ends. Next, in the period from time T1 to T2 (idle period), the ram 120 continues to descend. During this idling period, the ram speed is adjusted to be the target speed (molding speed) Vf.

  During the idling period, the upper mold 200 and the lower mold 300 are in contact with each other, and the prepreg PPG is held between the blank holders 240 and 340 as shown in FIG. Then, at time T2 when the idle running period ends, as shown in FIG. 4B, the punch 320 comes into contact with the prepreg PPG and molding of the prepreg PPG is started. As is apparent from this, the molding speed Vf refers to the ram speed at the time when the molding of the prepreg PPG is started.

  During the period from time T2 to T3 (molding period), as described above, the prepreg PPG is deformed by pressure. When the time when the molding period ends approaches the time point T3, the molded prepreg PPF is sandwiched between the convex part 321 of the punch 320 (FIG. 3) and the concave part 228 of the die 220, and the deformation resistance is large. Become. Therefore, the ram speed decreases rapidly as the time approaches the time point T3. Then, at time T3, the ram 120 (FIG. 1) reaches the lower end P1, and the ram speed becomes zero. After the time point when the ram 120 of time T3 reaches the lower end P1 (holding period), the ram 120 is held at the position of the lower end P1 with pressure applied to the prepreg PPF.

In the example of FIG. 6, the ram speed is adjusted in the idling period from time T1 to T2, but adjustment of the ram speed can be omitted. In this case, the acceleration of the ram 120, the position of the upper end P0, the position of the lower end P1, and the like are adjusted so that molding is started in a state where the molding speed Vf reaches the maximum speed Vx.

  FIG. 7 is a graph showing the operating state of the press device in the molding process of CFRTP. The graph of FIG. 7 is an enlarged graph of the vicinity of the molding period in the graph of FIG.

  As described above, the punch 320 comes into contact with the prepreg PPG as shown in FIG. 4B at the time T2 when the idle running period ends and the molding period starts. At this time, since the punch 320 is not yet pushed into the die 220, the ram 120 is located at a position (molding start position) Pf above the lower end P1. During the molding period, the ram 120 moves downward by the distance Sf between the molding start position Pf and the lower end P1. The distance Sf is a stroke (stroke) in which the ram 120 moves from the molding start position Pf toward the lower end P1 and the prepreg PPG is molded, and can also be referred to as a “molding stroke Sf”.

  As shown in FIG. 7, the ram speed is kept substantially constant from the molding speed Vf at time T2 when the ram 120 reaches the molding start position Pf to the vicinity of the lower end P1. In this way, the ram speed is maintained sufficiently high until the ram 120 reaches the vicinity of the lower end P1. Thereby, since the temperature of the prepreg PPG during molding is maintained sufficiently high, the moldability of the prepreg PPG can be further increased, and the time required for molding can be shortened. Further, by maintaining the ram speed sufficiently high over almost the entire area of the molding stroke Sf, the voids (voids) generated before or during molding are crushed well. Therefore, the amount of voids in the molded prepreg PPF can be reduced.

  In order to express these effects more reliably, the ram speed in the vicinity of the lower end P1 may be set to a certain level or more. Specifically, the ram speed (terminal speed) Vt at a position where the distance (terminal distance) St from the lower end P1 is sufficiently short (terminal position near the terminal) may be 100 mm / s or more. This end distance St can be determined based on the molding stroke Sf (for example, 1/5 of the molding stroke Sf). In addition, the above-mentioned effect can be expressed more reliably as the terminal distance St is shorter. Therefore, the terminal distance St is preferably set to 1/5 or less of the molding stroke Sf, and more preferably 1/10 or less.

  As described above, the molding speed Vf, which is the ram speed at the molding start time (time T2) is faster than the terminal speed Vt. However, if the molding speed Vf is too fast, the prepreg at the molding start time. There is a possibility that the moldability of PPG may decrease. Therefore, the molding speed Vf is preferably set to a speed close to the terminal speed Vt. Specifically, the molding speed Vf is preferably 2 times or less, more preferably 1.5 times or less of the terminal speed Vt. Thus, by making the molding speed Vf close to the terminal speed Vt, the moldability of the prepreg PPG at the molding start time can be maintained well.

  As described above, according to the first embodiment, by setting the terminal speed Vt of the ram 120 to 100 mm / s or more, the molding time of the prepreg PPG is improved and the molding time of the prepreg PPG is improved while reducing the time required for the molding. In addition, the amount of voids in the prepreg PPF can be reduced. Furthermore, by setting the molding speed Vf, which is the ram speed at the molding start time, to be a speed close to the terminal speed Vt, the moldability of the prepreg PPG at the molding start time can be maintained well.

  Further, as described above, in the first embodiment, pressure is applied to the molded prepreg PPF in a state where the prepreg PPF is in direct contact with the molds 200 and 300 (FIG. 4). Therefore, the holding time which is the length of the holding period can be shortened, and the cycle time from taking the heated prepreg PPG into the press apparatus 100 until taking out the molded prepreg PPF can be shortened.

  According to the first embodiment, the cushion 390 is disposed between the lower mold 300 and the bolster 130, but the cushion 390 can be omitted. However, the ram 120 is raised by the reaction force applied when reaching the lower end, and the separation (bound) between the upper mold 200 and the lower mold 300 is suppressed, and the prepreg PPF formed by the bounce of the molds 200 and 300 is suppressed. It is preferable to dispose the cushion 390 in that it can reduce the risk of damaging it. In particular, in the first embodiment, since the terminal speed Vt is high (100 mm / s or more), the reaction force applied to the ram 120 tends to increase. Therefore, when forming the prepreg PPG as in the first embodiment, it is preferable to use the cushion 390.

  In the first embodiment, the cushion 390 is configured by arranging a plurality of cylindrical urethane rubbers, but the configuration of the cushion is not limited thereto. For example, plate-like urethane rubber can be used as a cushion, and the cushion can be formed using other types of rubber. Furthermore, as a cushion, in order to apply sufficient pressure to the molded prepreg PPF, it is preferable that the repulsive force when the ram 120 reaches the lower end is increased, and then the repulsive force decreases. Such a cushion can be realized by disposing an elastic body in the dilatancy fluid. Such a cushion can also be realized by using a hydraulic circuit whose movement resistance decreases as the stroke increases.

  Furthermore, in 1st Embodiment, although the servo screw press apparatus is used as the press apparatus 100, other press apparatuses, such as a servo crank press which drives a crank with a servomotor, can also be used. However, in a press apparatus using a crank, the lower end is set at the bottom dead center, so that the ram speed changes almost linearly from a position somewhat away from the lower end to the lower end. Therefore, it is difficult to sufficiently increase the terminal speed Vt by using a press device using a crank. Furthermore, as described above, it is extremely difficult to achieve the molding speed Vf close to the terminal speed Vt with a press device using a crank. Therefore, as shown in the first embodiment, it is preferable to use a servo screw press device in order to perform CFRTP molding.

A5. Example:
As an example of the first embodiment, a prepreg molding test was performed, and a molded product obtained by the molding test was evaluated. In the molding test, three types of sheets having different configurations of the matrix material and the reinforcing fibers were prepared, and the prepared sheets were laminated to prepare three types of test materials (A to C). The composition of the prepared test material is as shown in Table 1 below.

  As shown in Table 1, the test materials A and B were prepared by laminating 10 sheets of 0.2 mm thick using nylon 6 (PA6) as a matrix material. Further, the test material A was prepared using a sheet in which the reinforcing fibers were plain weave, and the test material B was prepared using a sheet in which the reinforcing fibers were twilled. Test material C was prepared by laminating eight sheets of 0.25 mm thickness using nylon 6,6 (PA66) as a matrix material. Further, the test material C was prepared using a sheet in which the reinforcing fibers are twilled.

<Outline of molding test>
After preparing the test material, a molding test was performed using the prepared test material. In the molding test, the prepared test material was heated to a predetermined temperature with a heater. The heating temperature was set according to the type of matrix material. Specifically, in the test materials using PA6 as the matrix material (test materials A and B), the heating temperature is set to 260 ° C., 280 ° C. or 300 ° C., and the test material using PA66 as the matrix material ( In test material C), the heating temperature was set to 280 ° C, 300 ° C or 320 ° C.

  The heated test material was placed on the upper part of the lower mold (lower mold 300 in FIG. 3) placed on the bolster of the servo screw press apparatus. In addition, in order to prevent that the temperature of a test material falls because a test material contacts a lower mold | type, the arrangement | positioning of a test material was performed using the jig | tool for floating a test material in a hollow. The mold used for molding is a mold for a deep drawing test in which a test material is molded into a hemisphere having a radius of about 30 mm. The mold temperature was set to room temperature (RT), 50 ° C., 100 ° C., or 150 ° C.

The test material was shape | molded by operating a screw press apparatus (FIG. 2) after arrangement | positioning to the lower mold | type upper part of a test material. The molding speed (ram speed at the start of molding) was set to any one of 150 mm / s, 250 mm / s, 300 mm / s, 350 mm / s and 365 mm / s. As a comparative example, it was also molded test set the forming speed to 50 mm / s. As a preliminary test prior to the actual molding test, the behavior change of the ram with and without the cushion was evaluated and the molding speed was measured.

  During molding, the temperature of the test material was measured in order to evaluate the temperature change of the test material during molding. The temperature was measured by attaching a thermocouple to the test material. The temperature of the test material was measured at the center of the test material and at the end near the blank holder. Hereinafter, the temperature measured at the central portion is referred to as the central temperature, and the temperature measured at the end is referred to as the end temperature.

  After the molding of the test material was completed, the pressure on the test material was maintained for 10 seconds, and then the test material (molded product) molded by raising the ram was taken out. The molded product thus obtained was evaluated for formability by observing the appearance and void amount by observing the cross-sectional structure.

<Preliminary test results: Change in ram behavior>
In order to evaluate the change in the behavior of the ram depending on the presence or absence of a cushion, a molding test was performed using the test material B. In the molding test without a cushion, the heating temperature of the test material was 300 ° C., and in the molding test with the cushion provided, the heating temperature of the test material was 280 ° C. As the cushion, flat urethane rubber was used. The mold temperature was set to 50 ° C. and the molding speed was set to 150 mm / s in both the state where the cushion was provided and the state where the cushion was not provided.

  8 and 9 are graphs showing the results of evaluating the behavior change of the ram with and without the cushion. FIG. 8 shows the time change of the ram displacement and the ram speed when the cushion is not provided, and FIG. 9 shows the time change of the ram displacement and the ram speed when the cushion is provided. Note that the graphs shown in FIGS. 8 and 9A are drawn in the same manner as the graph shown in FIG. 6, and FIG. 9B is an enlarged graph of FIG. The explanation about the graph is omitted.

As shown in FIG. 8, in the state where the cushion is not provided, when the ram reaches the lower end, the ram speed greatly fluctuated in the minus direction (ram rising direction). From this, it was found that when the cushion was not provided, the mold bounced greatly even when the molding speed was 150 mm / s.

  On the other hand, as shown in FIG. 9 (a), by providing the cushion, the large fluctuation in the negative direction of the ram speed that appeared in the state where the cushion was not provided (FIG. 8) did not appear. From this, it was confirmed that the bounce of the mold was suppressed by providing the cushion. As shown in FIG. 9 (b), the ram displacement once sinks by about 0.6 mm, and when recovering from this sinking, the ram speed swings in the negative direction. Therefore, it is considered that the ram speed in the minus direction in the state where the cushion is provided is due to the spring back by the cushion. From this, it was found that the bounce of the mold is sufficiently suppressed by providing the cushion.

<Preliminary test results: actual measurement of molding speed and end speed>
The measurement data when evaluating the behavior change of the ram with and without the cushion were analyzed, and the molding speed and the terminal speed were measured. FIG. 10 is a graph showing actual measurement results of the molding speed and the terminal speed. In the graph of FIG. 10, the horizontal axis represents the ram speed, and the vertical axis represents the ram displacement. In the graph of FIG. 10, the ram displacement is drawn so that the lower end of the ram is 0 mm. At this time, the position of the ram where the ram displacement is 30 mm is the molding start position where the punch and the test material come into contact. In the graph of FIG. 10, a solid line indicates an actual measurement result in a state where the cushion is provided, and a broken line indicates an actual measurement result in a state where the cushion is not provided.

As shown in FIG. 10, the ram speed at the molding start position, that is, the molding speed was 150 mm / s in both the state where the cushion was provided and the state where the cushion was not provided. Further, when the terminal distance is 1/5 of the molding stroke, that is, 6 mm, the terminal speed is 134 mm / s in both the state where the cushion is provided and the state where the cushion is not provided. From this, it was confirmed that the termination speed could be 100 mm / s or more by setting the molding speed to 150 mm / s. Furthermore, as can be seen from the graph of FIG. 10, it was found that by setting the molding speed to 150 mm / s, it is possible to increase the ram speed to 100 mm / s or more up to the vicinity of the lower end.

<Temperature change of test material during molding>
11 to 13 are graphs showing the temperature change of the test material during molding. In the graphs of FIGS. 11 to 13, the horizontal axis represents time, the left vertical axis represents temperature, and the right vertical axis represents ram displacement. Also, in the graphs of FIGS. 11 to 13, the solid line represents the ram displacement, the broken line represents the end temperature, and the alternate long and short dash line represents the center temperature. In these graphs, two dotted lines extending vertically indicate the molding start time and the molding end time. Therefore, the range between these two dotted lines corresponds to the molding period.

As shown in FIG. 11, when the mold temperature was set to 50 ° C., the end temperature decreasing rate during the molding period reached 950 ° C./s, and the end temperature at the end of molding became 153 ° C. Thus, when the mold temperature is set to 50 ° C., the rate of decrease in the end temperature is fast, so that it is considered that the moldability is reduced at the end of molding even when the molding speed is set to 300 mm / s.

On the other hand, as shown in FIGS. 12 and 13, when the mold temperature is set to 100 ° C., the rate of decrease in the end temperature during the molding period is about 1/2 to 1 when the mold temperature is set to 50 ° C. / 3. In the molding test showing the temperature change in FIGS. 12 and 13, the molding speed is set to 365 mm / s. For this reason, the end temperature at the end of molding exceeded 200 ° C. Therefore, if the mold temperature is set to 100 ° C. or higher and the molding speed is made faster than 300 mm / s, the end temperature is maintained sufficiently high over the entire molding period, and the moldability is sufficiently increased. It is considered possible.

<Appearance evaluation of molded products>
FIG. 14 is a photograph showing the appearance evaluation result of the molded product. FIG. 14A to FIG. 14C each show the appearance of a molded product formed by changing the mold temperature. In addition, all the molded products which show an external appearance in FIG. 14 are molded using the test material B as the test material, the heating temperature of the test material being 280 ° C., and the molding speed being 150 mm / s.

As shown in FIG. 14, as the mold temperature was lowered, the surface of the molded product did not exhibit gloss. From this, it was confirmed that when the mold temperature was lowered, the moldability was lowered. Such a tendency agrees with the result of evaluating the temperature change of the test material during molding. However, although the molded product showing the appearance evaluation results in FIG. 14 is molded at a lower molding speed than the molded product showing the temperature change evaluation results in FIGS. Even at room temperature (RT), it was possible to mold the molded product into a hemispherical shape. Further, when the mold temperature was 100 ° C., a glossy surface was formed. Thus, even if molding is performed at a relatively slow molding speed (150 mm / s), a certain degree of moldability can be secured because the termination speed is sufficiently high (100 mm / s or more). It is considered a thing.

<Evaluation of void amount>
FIG. 15 is an explanatory view showing a position where the void amount is evaluated in the molded product. FIG. 15A shows the direction of the molded product defined by the arrangement direction of the reinforcing fibers. Normally, as shown in FIG. 15A, the direction of the molded product of CFRTP is a direction parallel to the fiber arrangement direction called 0, 90 ° direction, and forms a 45 ° angle with the fiber arrangement direction. Is called the 45 ° direction. Of these directions, the direction in which voids are likely to occur is the 45 ° direction. Therefore, in evaluating the void amount, first, the molded product was cut along a line passing through the apex of the molded product and extending in the 45 ° direction. And the cross section which appeared by cutting | disconnection was observed, the area ratio of the void in the observed cross section was measured, and the amount of voids was evaluated.

  FIG. 15B shows the state of the cut surface of the molded product cut as described above. The numerical value shown in FIG. 15B represents the distance from the vertex. When the test material is molded into a hemispherical shape by deep drawing as in this example, the distance between the reinforcing fibers is increased in the molding process at a position inside the distance from the apex of 30 mm. On the other hand, when the distance from the apex is 40 mm, the reinforcing fibers are drawn from the outside, so that the interval between the reinforcing fibers is narrowed. Thus, since the direction of the force applied to the reinforcing fibers is reversed between the inside and outside of the region having a distance from the apex of 30 mm to 40 mm, voids are easily generated in the region indicated by the arrow. Therefore, the void amount was evaluated for the region indicated by the arrow in FIG.

16 to 18 are photographs showing the state of the cross section of the region where the void amount was evaluated. FIG. 16 shows a cross section of a molded product molded using the test material C as the test material, the heating temperature of the test material being 280 ° C., and the molding speed being 150 mm / s. FIG. 17 shows a cross section of a molded product molded using the test material B as the test material, the heating temperature of the test material being 280 ° C., and the molding speed being 365 mm / s. Further, FIG. 18, as a comparative example, a test material B used as a test material, the heating temperature of the test material and 280 ° C., shows a molded product of a cross section obtained by molding the molding rate as 50 mm / s. 16 (a), 17 (a), and 18 (a) show the state of the cross section of the test material that was only heated and not molded, and the others of FIGS. 16, 17, and 18. These photographs show the state of the cross section of the test material molded by changing the mold temperature.

As shown in FIG. 16, when the molding speed was set to 150 mm / s, the void area ratio of the test material subjected to heating alone was 6.96%, whereas in the molded product, the void area ratio was 0. It decreased greatly from 0.07% to 0.54%. From this, it was confirmed that the amount of voids in the molded product can be reduced by sufficiently increasing the termination speed. It was also found that the effect of reducing the amount of voids was enhanced as the mold temperature was lowered.

As shown in FIG. 17, even when the molding speed was set to 365 mm / s, the void area ratio of the test material that was only heated was 12.74%, whereas the molded article had a void area ratio of 12.74%. , Greatly decreasing from 0.32% to 0.78%. Further, similar to the case where the molding speed was set to 150 mm / s, there was a tendency that the effect of reducing the amount of voids was enhanced as the mold temperature was lowered.

On the other hand, when the extrusion rate and 50 mm / s as the comparative example, as shown in FIG. 18, the void area ratio by molding, although decreases from 12.74% to about 3%, the degree of reduction The molding speed was not as large as 150 mm / s or 364 mm / s. From this, it was found that it is important to increase the molding speed to a certain level or more in order to exhibit the effect of reducing the void amount. In general, voids are also generated during molding, but in this example, the amount of voids in the molded product could be sufficiently reduced. From these facts, it is estimated that it is important to sufficiently increase the terminal speed in order to more reliably reduce the amount of voids in the molded product.

B. Second embodiment:
In the first embodiment, as shown in FIG. 2, a cushion 390 is disposed between the lower mold 300 and the bolster 130 in order to suppress the bounce of the molds 200, 300. It is also possible to suppress the bounce of the mold. Specifically, the cushion 390 is omitted, and the bounce of the mold is suppressed by using a hydraulic cylinder (balance cylinder with a ram stop device) connected to an appropriately designed hydraulic circuit instead of the balance cylinder 171. Can do. Other configurations, functions, effects, and the like are the same as those in the first embodiment, and thus description thereof is omitted here.

  FIG. 19 is a hydraulic circuit diagram showing a configuration of a hydraulic circuit 20a connected to a balance cylinder 171a with a ram stop device (hereinafter also simply referred to as “balance cylinder 171a”). The hydraulic circuit 20a includes a tank 21a, a relief valve 22a with an electromagnetic valve (hereinafter also simply referred to as “relief valve 22a”), a check valve 23a, and a cock valve 24a.

  The tank 21a is connected to the P port of the relief valve 22a, the inlet port of the check valve 23a, and the first port of the cock valve 24a. The tank 21a is connected to the lower cylinder chamber of the balance cylinder 171a. On the other hand, a T port of the relief valve 22a, an outlet port of the check valve 23a, and a second port of the cock valve 24a are connected to the upper cylinder chamber of the balance cylinder 171a. Since the cock valve 24a is normally in a closed state, the description thereof is omitted here.

  The tank 21a stores hydraulic oil for the hydraulic circuit 20a. The inside of the tank 21a is pressurized by the compressed air. The hydraulic oil flows into the upper cylinder chamber of the balance cylinder 171a through the check valve 23a connected to the tank 21a, so that the cylinder rod 172a of the balance cylinder 171a can be lowered and the ram 120 can be lowered.

  As shown in FIG. 19, the tank 21a and the upper cylinder chamber of the balance cylinder 171a are connected via a check valve 23a, but since the cylinder rod 172a is connected to the upper cylinder chamber, The cross-sectional area of the cylinder is reduced. Therefore, by pressurizing the inside of the tank 21a, a force that pushes the cylinder rod 172a upward acts and can support the weight of the ram 120 (FIG. 2) and the like. In addition, the resistance of the flow path to the upper cylinder chamber connected via the check valve 23a is higher than the resistance of the flow path to the lower cylinder directly connected to the tank 21a. This difference in flow path resistance also contributes to supporting the weight of the ram 120 and the like.

  In the relief valve 22a, when the operation power supply of the press apparatus 100 is cut off, the electromagnetic valve is closed. At this time, the hydraulic oil flows from the T port to the P port, and the hydraulic oil does not flow from the P port to the T port. That is, the relief valve 22a in the closed state functions as a check valve having the T port as an inlet port and the P port as an outlet port.

  On the other hand, when the operation power of the press apparatus 100 is turned on, the solenoid valve is opened. At this time, the relief valve 22a blocks the flow of hydraulic oil from the T port to the P port until the differential pressure of the T port with respect to the P port reaches a preset pressure (relief pressure). When the differential pressure exceeds the relief pressure, the hydraulic oil flows from the T port to the P port. That is, when the operation power of the press device 100 is turned on and the press device 100 operates, the relief valve 22a with a solenoid valve is equivalent to a general relief valve having a T port as an inlet port and a P port as an outlet port. It is. Therefore, in the second embodiment, it can be said that the tank 21a is connected to the tank 21a from the upper cylinder chamber of the balance cylinder 171a through the relief valve. Further, since the cylinder rod 172a moves upward when the ram 120 moves upward, the volume of the upper cylinder chamber is reduced when the ram moves upward.

  In this way, the relief valve 22a acts, and the check valve 23a blocks the flow of hydraulic oil from the upper cylinder chamber of the balance cylinder 171a to the tank 21a. Therefore, the flow of hydraulic oil from the upper cylinder chamber to the tank 21a is blocked until the differential pressure in the upper cylinder chamber with respect to the lower cylinder chamber of the balance cylinder 171a exceeds the relief pressure of the relief valve 22a.

  Usually, the reaction force applied to the ram 120 is smaller than the pressure generated by operating the press device 100. Therefore, by appropriately setting the relief pressure of the relief valve 22a, the rise of the ram 120 due to the reaction force is suppressed, and the bounce of the mold is suppressed. On the other hand, when the ram 120 is raised by rotating the screw 140, the pressure difference between the upper cylinder chamber and the lower cylinder chamber of the balance cylinder 171a becomes sufficiently large. Therefore, even if the second embodiment is applied, the operation of raising the ram 120 is not affected.

  Thus, also by 2nd Embodiment, since the bound of a metal mold | die can be suppressed, it becomes possible to make terminal speed Vt sufficiently quick. Therefore, as in the first embodiment, the moldability of the prepreg PPG can be improved and the amount of voids in the molded prepreg PPF can be reduced. Furthermore, the second embodiment is preferable to the first embodiment in that the pressure applied to the prepreg PPF can be increased when the ram 120 reaches the lower end. On the other hand, 1st Embodiment is more preferable than 2nd Embodiment at the point which can suppress the bounce of a metal mold | die more easily.

  In the second embodiment, the balance cylinder 171a is connected from the upper cylinder chamber to the tank 21a via a relief valve 22a, and is connected from the tank 21a to the upper cylinder chamber via a check valve 23a. However, in general, it is only necessary that the upper cylinder chamber is connected to the tank 21a via the relief valve 22a. In this case, an electromagnetic valve may be provided instead of the check valve 23a, and the electromagnetic valve may be closed when the ram 120 reaches the lower end, and the upper cylinder chamber and the lower cylinder of the balance cylinder 171a. The chamber may be connected by a check valve or a solenoid valve.

C. Third embodiment:
FIG. 20 is an explanatory diagram illustrating a configuration of a press device 100b according to the third embodiment. 3rd Embodiment suppresses the bounce of the metal mold | die 200,300 in a different aspect from 1st Embodiment and 2nd Embodiment.

  In the press device 100b of the third embodiment, instead of the bolster 130, a ram (lower ram) 130b configured to be movable in the vertical direction and a feed screw mechanism 180b for moving the lower ram 130b in the vertical direction are provided. It differs from the press device 100 (FIG. 2) of the first embodiment in that it has the slide guide 160b extending vertically downward in order to suppress the rotation of the lower ram 130b with respect to the central axis. ing. Other configurations, functions, effects, and the like are the same as those in the first embodiment, and thus description thereof is omitted here.

  As shown in FIG. 20, the lower ram 130b has a ram body 131b provided with a hole 139b along the central axis, and a pressure sensor 132b attached to the ram body 131b. The ram body 131b slides with respect to the slide guide 160b at its end. Thus, the lower ram 130b is restricted from rotating around the central axis and is movable in the vertical direction.

  The feed screw mechanism 180b includes an integrally formed shaft 181b and screw 182b, a pulley 183b, and a toothed belt 184b. Although not shown, the feed screw mechanism 180b includes a servo motor 153 (hereinafter also referred to as “upper servo motor”) provided in the press device 100 of the first embodiment shown in FIG. Further, another servo motor (hereinafter also referred to as “lower servo motor”) is provided. The shaft 181b is fitted into a hole 139b provided in the ram body 131b. A male screw is formed on the screw 182b.

  The pulley 183b is provided with a hole 189b along the central axis. On the inner surface of the hole 189b, a female screw that meshes with a male screw provided on the screw 182b is formed. The toothed belt 184b is attached so as to bridge the pulley 183b and a lower servo motor (not shown). Therefore, by rotating the lower servo motor, the pulley 183b rotates around the central axis.

  Although not shown, the pulley 183b is restricted from moving in the vertical direction. Therefore, when the pulley 183b rotates, the screw 182b having a male screw meshed with the female screw of the pulley 183b, the shaft 181b integrally formed with the screw 182b, and the lower ram 130b in which the shaft 181b is fitted are rotated. It moves in the vertical direction according to.

  As shown in FIG. 20, in the press device 100 b according to the third embodiment, the lower ram 130 b is smaller and lighter than the upper ram 120. Furthermore, the screw 182b and the pulley 183b for moving the lower ram 130b are smaller than the screw 140 and the pulley 150 for moving the upper ram 120. Therefore, the inertia of the lower ram drive system when the lower ram 130b, the screw 182b and the pulley 183b are viewed as a whole is smaller than the inertia of the upper ram drive system when the upper ram 120, the screw 140 and the pulley 150 are viewed as a whole. .

  As shown in FIG. 20, the molds 200 and 300 are respectively attached to an upper ram 120 (hereinafter also referred to as “upper ram 120”) and a lower ram 130b of the press device 100b. Therefore, it can be said that the two rams 120 and 130b define the relative positions of the two molds 200 and 300.

  FIG. 21 is a block diagram illustrating the configuration of the servo motor drive control function in the third embodiment. As described above, the servo motor 185b is added to the press device 100b of the third embodiment. Therefore, the motor control unit 191b is configured to drive and control the two servo motors 153 and 185b. The added servo motor 185b is also provided with an encoder 192b. The output signal of the encoder 192b is supplied to the speed detector 12b and the position detector 13b of the controller 10b. The output signal of the pressure sensor 132b provided in the lower ram 130b is supplied to the pressure detection unit 15b added to the control unit 10b.

  The control part 10b of 3rd Embodiment has the speed detection part 12b, the position detection part 13b, and the torque detection part 14b. These functional units 12b to 14b have corresponding functional units 12 to 14 in the control unit 10 of the first embodiment, and the configuration of these functional units is changed to correspond to the two servo motors 153 and 185b. Other than that, the second embodiment is the same as the first embodiment. The pressure detector 15b added in the controller 10b of the third embodiment detects the pressure applied to the lower ram 130b (FIG. 20) based on the output signal of the pressure sensor 132b.

  The drive condition determination unit 11b included in the control unit 10b according to the third embodiment includes the rotation angles and rotations of the two servo motors 153 and 185b detected by the speed detection unit 12b, the position detection unit 13b, and the torque detection unit 14b. Based on the speed and driving torque, the pressure applied to the lower ram 130b detected by the pressure detector 15b, and the preset operating conditions of the press device 100b, the driving conditions of the two servo motors 153 and 185b are determined. . Thereby, the respective positions and speeds of the upper ram 120 and the lower ram 130b and the pressure applied to the prepreg PPG, the lower mold 300, etc., which are workpieces, are controlled.

  FIG. 22 is an explanatory diagram illustrating an operation mode of the press apparatus 100b according to the third embodiment. In FIG. 22, for convenience of illustration, only the portion of the press device 100 b necessary for explaining the mode of operation is illustrated, and the die 220 (see FIG. 3) and only the punch 320 are shown.

  In the press apparatus 100b, in the initial state, as shown in FIG. 22A, the upper ram 120 is located at the position (initial position) UP0, and the lower ram 130b is located at the position (initial position) LP1. . In addition, the prepreg PPG to be molded is located between the upper mold 200 and the lower mold 300. When the operation of the press device 100b is started, the upper servo motor 153 that moves the upper ram 120 is driven, and the upper ram 120 starts to descend.

  When the upper ram 120 is lowered to the position UP1, as shown in FIG. 22B, the mold, that is, the upper mold 200 (die 220) and the lower mold 300 (punch 320), and the prepreg PPG come into contact with each other. PPG molding is started. The contact between the mold and the prepreg PPG is determined based on whether or not the pressure (detected pressure) detected by the pressure sensor 132b exceeds a preset pressure threshold (pressure threshold).

  When the detected pressure exceeds the pressure threshold, it is determined that the mold and the prepreg PPG are in contact with each other, and the lower servo motor 185b is driven in a direction to raise the lower ram 130b. At this time, the lower servo motor 185b is controlled (pressure control) so that the pressure applied to the pressure sensor 132b becomes a preset pressure value. Thus, by controlling the pressure of the lower servo motor 185b, the pressure necessary for forming the prepreg PPG is also provided by the lower servo motor 185b.

  In the example of FIG. 22, the drive of the lower servo motor 185b is started from the time when the mold and the prepreg PPG come into contact with each other, but the drive of the lower servo motor 185b is as shown in FIG. In addition, the driving of the lower servo motor 185b can be started when the prepreg PPG is sandwiched between the blank holders 240 and 340, or when a part of the punch 320 is pushed into the die 220. In this case, the pressure threshold value may be adjusted according to the time point when the lower servo motor 185b starts to be driven.

  After molding of the prepreg PPG is started, the upper ram 120 and the lower ram 130b each move in the vertical direction, and as shown in FIG. 22 (c), the upper ram 120 is in the position UP2 and the lower ram 130b is in the position. LP2 is reached. When the upper ram 120 and the lower ram 130b reach the positions UP2 and LP2, respectively, the molding of the prepreg PPG is finished, and the molded prepreg PPF is sandwiched between the upper mold 200 (die 220) and the lower mold 300 (punch 320). It becomes a state. It can be said that the positions UP2 and LP2 of the upper ram 120 and the lower ram 130b at this point are at the end positions. As described above, since the pressure of the lower servo motor 185b is controlled, the pressure applied to the prepreg PPG during molding can be changed by appropriately setting the operating conditions of the press device 100b. For example, the pressure during molding may be increased so that the prepreg PPG is molded faster, and the pressure at the end of molding is increased so as to increase the bounce suppression effect described later. Anyway.

  As shown in FIG. 22C, when the upper mold 200 and the lower mold 300 come into contact with each other, a reaction force that pushes the upper ram 120 upward is applied to the upper ram 120, and the lowering speed of the upper ram 120 decreases. Therefore, in the third embodiment, when the upper mold 200 and the lower mold 300 come into contact with each other, the lower ram 130b is driven so as to compensate for the decrease in the lowering speed of the upper ram 120 due to the reaction force. In this way, the lower ram 130b is driven so as to compensate for the decrease in the lowering speed of the upper ram 120, that is, to follow the movement of the upper ram 120, thereby suppressing the bounce of the mold. it can.

  As described above, in the third embodiment, since the inertia of the lower ram drive system is smaller than the inertia of the upper ram drive system, the speed of the lower ram 130b is easier than that of the upper ram 120. Can be controlled. Therefore, according to the third embodiment, it is possible to more reliably compensate for a decrease in the lowering speed of the upper ram 120 and to more reliably suppress the mold bounce. Further, since the speed of the lower ram 130b is easy to control, the relative speed between the upper ram 120 and the lower ram 130b during molding of the prepreg PPG (corresponding to the ram speed of the first embodiment). Adjustment) becomes easy. As a result, the termination distance St can be further shortened, or the termination speed Vt can be further increased, and the amount of voids in the molded prepreg PPF can be more reliably reduced.

  After the upper mold 200 and the lower mold 300 are in contact with each other as shown in FIG. 22C, the upper ram 120 is driven to decelerate, and the lower ram 130b is driven to follow the lowering of the upper ram 120. Is done. Thereby, the state which the upper mold | type 200 and the lower mold | type 300 contacted can be maintained, and a pressure can be continuously applied to the shape | molded prepreg PPF.

  By driving the upper ram 120 to decelerate and driving the lower ram 130b to follow the lowering of the upper ram 120, as shown in FIG. 22 (d), the upper ram 120 and the lower ram 130b Respectively reach positions UP3 and LP3 and stop. After the upper ram 120 and the lower ram 130b are stopped, the upper ram 120 and the lower ram 130b are maintained so that pressure is continuously applied to the prepreg PPF until the temperature of the molded prepreg PPF sufficiently decreases. Are held at the positions UP3 and LP3, respectively.

  As is clear from the above description, the position of the ram in the third embodiment can be defined by the relative positional relationship between the upper ram 120 and the lower ram 130b. Therefore, as shown in FIG. 22 (d), when the upper ram 120 and the lower ram 130b are at the positions UP3 and LP3, respectively, the upper ram 120 and the lower ram 130b are at the positions UP2 and LP2, respectively. Similar to (FIG. 22C), it can be said that the ram is located at the end.

  When a preset holding time elapses with the upper ram 120 and the lower ram 130b held at the positions UP3 and LP3, respectively, the temperature of the prepreg PPF is lowered and molded until the holding time elapses. The prepreg PPF cured. The prepreg PPF molded and cured in a desired shape is taken out of the press device 100b by returning the upper ram 120 and the lower ram 130b to the initial positions UP0 and LP1 after the holding time has elapsed.

  As described above, the bounce of the mold can be suppressed also by the third embodiment. Therefore, it is possible to sufficiently increase the terminal velocity Vt, so that the moldability of the prepreg PPG is improved and the amount of voids in the molded prepreg PPF is reduced as in the first and second embodiments. Can be reduced.

  Furthermore, in the third embodiment, since the inertia of the lower ram drive system is smaller than the inertia of the upper ram drive system, the speed of the lower ram 130b can be adjusted more easily than the upper ram 120. Therefore, it becomes easier to adjust the ram speed during molding of the prepreg PPG, and the terminal distance St can be further shortened or the terminal speed Vt can be further increased, so that the voids in the molded prepreg PPF can be reduced. The amount can be further reliably reduced. In this respect, the third embodiment is preferable to the first embodiment and the second embodiment. On the other hand, 1st Embodiment and 2nd Embodiment are more preferable than 3rd Embodiment at the point which can make the structure of a press apparatus and its control method simpler.

  Generally, in order to make the adjustment of the speed of the lower ram 130b easier, the inertia of the lower ram drive system may be made smaller than the inertia of the upper ram drive system. Therefore, unlike the third embodiment, each of the parts 130b, 182b, 183b constituting the lower ram drive system need not be smaller than the parts 120, 140, 150 constituting the upper ram drive system. In addition, the inertia of the lower ram drive system is not necessarily smaller than the inertia of the upper ram drive system. However, it is preferable to make the inertia of the lower ram drive system smaller than the inertia of the upper ram drive system in order to further shorten the end distance St or further increase the end speed Vt.

D. Variation:
The present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

D1. Modification 1:
In each of the above embodiments, the present invention is applied to the molding of a prepreg PPG in which a carbon fiber fabric is impregnated with a sheet impregnated with a matrix material, but the present invention is applied in one direction in addition to the molding of such a prepreg PPG. A prepreg formed by laminating sheets of carbon fiber impregnated into a bundle of arranged carbon fibers, a single layer sheet of CFRTP, or a sheet or prepreg containing carbon fibers only in a part of the matrix material, or already molded It can also be applied to additional molding of CFRTP materials. Note that these prepregs, single-layer sheets, CFRTP materials, and the like are all objects of molding and can be collectively referred to as “materials to be molded”.

D2. Modification 2:
In each of the above embodiments, the present invention is applied to the molding of CFRTP. However, the present invention is not limited to CFRTP, but a glass fiber reinforced thermoplastic resin using glass fibers as reinforcing fibers, and an aromatic polyamide system as reinforcing fibers. The present invention can be applied to molding various fiber reinforced thermoplastic resins such as fiber reinforced thermoplastic resins using resin fibers.

D3. Modification 3:
In each of the above embodiments, the present invention is applied to CFRTP deep drawing. However, the present invention can be applied to general forming such as stamping in addition to deep drawing. In the case of molding such as stamping, the blank holders 240 and 340 provided in the molds 200 and 300 in order to suppress generation of wrinkles during molding can be omitted.

DESCRIPTION OF SYMBOLS 10, 10b ... Control part 11, 11b ... Drive condition determination part 12, 12b ... Speed detection part 13, 13b ... Position detection part 14, 14b ... Torque detection part 15b ... Pressure detection part 20a ... Hydraulic circuit 21a ... Tank 22a ... Electromagnetic Relief valve with valve 23a ... Check valve 24a ... Cock valve 100, 100b ... Press device 110 ... Frame 111 ... Outer shell plate 112 ... Inner shell plate 113 ... Top plate 114 ... Shaft fixing member 115 ... Thrust bearing 116 ... Bushing 119 ... Opening 120 ... Ram 121 ... Ram main body 122 ... Female screw plate 128 ... Female screw 129 ... Hole 130 ... Bolster 130b ... Ram 131b ... Ram main body 132b ... Pressure sensor 139b ... Hole 140 ... Screw 141 ... Shaft 142 ... Large diameter part 143 ... Male screw 150: Rotation drive unit 151: Pulley 1 2 ... toothed belt 153 ... servo motor 160, 160b ... slide guide 170 ... balancer 171, 171a ... balance cylinder 172, 172a ... cylinder rod 173 ... connection arm 180b ... feed screw mechanism 181b ... shaft 182b ... screw 183b ... pulley 184b ... Toothed belt 185b ... servo motor 189b ... hole 191,191b ... motor control unit 192,192b ... encoder 200 ... upper mold 210 ... base 218 ... air hole 220 ... die 228 ... concave 229 ... air hole 230 ... die fixing part 240 ... Blank holder 249 ... Concavity 250 ... Shim 300 ... Lower mold 310 ... Base 320 ... Punch 321 ... Convex part 330 ... Liner 338, 348 ... Hole 340 ... Blank holder 360 ... Spring pressing part 39 ... cushion 910 ... heating device PPF, PPG ... prepreg

Claims (5)

A molding apparatus for molding a fiber-reinforced thermoplastic resin molding material including a matrix material of thermoplastic resin and reinforcing fibers,
A heating device for heating the molding material to a temperature higher than the melting point of the matrix material;
A first mold formed with irregularities;
A second mold in which irregularities corresponding to the irregularities of the first mold are formed;
A ram that fixes the first mold and defines a relative positional relationship between the first and second molds, a bolster on which the second mold is mounted, and the ram A press device having a balancer for pushing up ,
With
The bolster is fixed with respect to the press device,
The balancer has a tank for storing a working fluid, and a balance cylinder driven by the working fluid,
The cylinder chamber whose volume is reduced when the ram of the balance cylinder moves upward is connected to the tank through a relief valve.
The temperatures of the first and second molds are set to be equal to or lower than the melting point of the matrix material,
The pressing device is configured to drive the ram so as to form the molding material by sandwiching the molding material heated by the heating device between the first and second molds. And
The ram has a ram speed at the time when the ram reaches a position near the terminal end on the molding start position side where the molding of the molding material is started, near the terminal position where the molding of the molding material is finished. It is driven so that a certain terminal speed is 100 mm / s or more.
Molding equipment. A molding apparatus for molding a fiber-reinforced thermoplastic resin molding material including a matrix material of thermoplastic resin and reinforcing fibers,
A heating device for heating the molding material to a temperature higher than the melting point of the matrix material;
A first mold formed with irregularities;
A second mold in which irregularities corresponding to the irregularities of the first mold are formed;
A pressing device having a ram defining a relative positional relationship between the first and second molds;
With
The temperatures of the first and second molds are set to be equal to or lower than the melting point of the matrix material,
The pressing device is configured to drive the ram so as to form the molding material by sandwiching the molding material heated by the heating device between the first and second molds. And
The ram has a ram speed at the time when the ram reaches a position near the terminal end on the molding start position side where the molding of the molding material is started, near the terminal position where the molding of the molding material is finished. It is driven so that a certain terminal speed is 100 mm / s or more ,
The ram has a first ram to which the first mold is fixed, and a second ram to which the second mold is fixed;
The pressing device drives the second ram so as to follow the movement of the first ram after the time when the ram reaches the end position by driving the first ram.
Molding equipment. The ram, the ram speed in the forming start position are driven to be equal to or less than 2 times the terminal velocity, the molding apparatus according to claim 1 or 2 wherein. Distance between the end position and the end position near is 1/5 of the distance between the end position and the forming start position, the molding apparatus according to any one of claims 1 to 3. The press apparatus is a screw press apparatus, the servo motor is a servo screw press apparatus for driving a ram, molding apparatus according to any one of claims 1 to 4.