JP6320460B2 - Press molding apparatus and press molding method for molded products containing reinforcing fibers and thermoplastic resin - Google Patents

Description

The present invention relates to a press molding apparatus and a press molding method for a molded product containing reinforcing fibers and a thermoplastic resin.

The thing described in patent document 1 is known as a press molding apparatus and press molding method of the molded article containing a reinforced fiber and a thermoplastic resin. According to Patent Document 1, it is described that a carbon fiber reinforced composite material using a thermoplastic resin is cut and pressed in a press molding apparatus. Rather, in Patent Document 1, “a carbon fiber reinforced composite material using a thermoplastic resin is molded so as not to be reheated, and all the processing required for the molding is performed by a single molding. Re-heating the material is denied.

However, on the other hand, it is also known that, as in Patent Document 2, a prepreg material in which a reinforcing fiber is impregnated with a thermoplastic resin is molded by heating to a temperature higher than the melting point of the thermoplastic resin, and then cooled to a temperature lower than the melting point. ing.

JP 2014-94489 A (Claims 1, 0016, FIGS. 1 and 2) JP 2007-1089 A (Claim 1, 0041, FIG. 1, FIG. 4, FIG. 5)

In the case of the above-mentioned patent document 1, since reheating of the prepreg material is not performed, when one molded product is formed from a plurality of prepregs, or when a reinforcing fiber and a resin sheet are separately inserted into the cavity, one molded product Obviously, it is not intended for those that mold. Patent Document 1 is suitable for forming a molded product by simply bending a prepreg material to a certain degree, but it is not suitable for forming a molded product in a more complicated shape than a certain level.

On the other hand, since Patent Document 2 performs molding after heating to a temperature equal to or higher than the melting point of the thermoplastic resin to be molded, it is also possible to heat and join a plurality of prepreg tapes to mold a molded product. However, in the case of Patent Document 2, since only pressurization is performed at a melting point or higher, there is a case where the reinforcing fibers cannot be satisfactorily impregnated with the thermoplastic resin and voids remain. In some cases, the air remains between the prepregs stacked. Furthermore, in patent document 2, it was necessary to shape | mold a molding material in the shape which can be installed in a metal mold | die in the process of manufacturing an intermediate body. That is, in Patent Document 2, since the molding material is not cut during press molding, the preparatory work before molding becomes complicated.

Accordingly, in view of the above problems, the press molding apparatus and press molding method for a molded product including the reinforcing fiber and the thermoplastic resin of the present invention are well impregnated with the thermoplastic resin in the reinforcing fiber, and the internal voids and the surface An object of the present invention is to mold a molded product in which the concave portion is eliminated as much as possible. Another object of the present invention is to form a molded article containing a reinforcing fiber and a thermoplastic resin having a shape other than a rectangular flat plate, and a molded article containing a reinforcing fiber and a thermoplastic resin having different thicknesses by a relatively simple work process. And

In the press molding apparatus according to claim 1 of the present invention, a cavity for molding a molding material is formed between a fixed mold and a movable mold in a press molding apparatus for a molded product including a reinforcing fiber and a thermoplastic resin. A die, a cutting device in which a cutting blade advances with respect to the die provided with the actuator by an operation of the actuator to cut an excess portion of the molding material, a suction device capable of decompressing the inside of the cavity, and the molding A molding material provided with a heating means capable of heating the material to a melting point or higher and a cooling means capable of cooling the molding material to a predetermined temperature or lower, and preheated to a temperature higher than the thermal deformation temperature of the thermoplastic resin by the cutting device. evacuable cavity is closed by the surplus portion is cut is formed from, while none of the cavity and a vacuum by the suction device, said within the cavity by elevating the temperature of the mold Start the pressurization of the molding material the temperature of the frame members or die after the heated state above the melting point of the molding material, the molding material or mold or before or after pressurization simultaneously with the start of the molding member Is started to cool below a certain temperature.

A press molding apparatus according to a second aspect of the present invention is the press molding apparatus according to the first aspect, wherein the mold is composed of an upper mold and a lower mold, and the upper mold when the preheated molding material is placed on the lower mold; lower mold temperatures are a a thermoplastic resin of the heat deformation temperature or a temperature below the melting point of the molding material, the cutting device evacuable cavity is closed by the surplus portion is cut from the molding material by the It is formed.

The press molding method according to claim 3 of the present invention is a press molding method of a molded product containing reinforcing fibers and a thermoplastic resin, wherein the reinforcing fibers and the heat are contained in a cavity formed between the fixed mold and the movable mold. A molding material containing a plastic resin is inserted, the excess part is cut from the molding material preheated to a temperature higher than the thermal deformation temperature of the thermoplastic resin by a cutting device, and the movable mold is closed by speed control or position control. The closed cavity is formed, and the atmosphere in the cavity is sucked by a suction device to reduce the pressure while heating the mold by heating means, and the temperature of the molding material or the mold is equal to or higher than the melting point of the molding material. And the cooling of the molding material or the mold is started to a certain temperature or less at the same time as or after the start of pressurization of the molding material.

The press molding method according to a fourth aspect of the present invention is the press molding method according to the third aspect, wherein the movable mold is moved in the opening / closing direction while the closed cavity is formed, or the fixed mold and the movable mold are arranged. A vibration is imparted to at least one of the molds.

The press molding method according to claim 5 of the present invention is the press molding method according to claim 3 or 4, wherein the thermoplastic resin molded article including the reinforcing fiber has a thick part, and the fixed mold and the movable mold. At least one of the molds is provided with a thick portion forming portion for forming the thick portion, and a molding material formed from an excessive portion cut by a cutting device is inserted into the thick portion forming portion. And pressurizing the molding material in the thick part forming part.

The press molding apparatus according to the present invention is a press molding apparatus for a molded product containing reinforcing fibers and a thermoplastic resin, a mold in which a cavity for molding a molding material is formed between a fixed mold and a movable mold, and an actuator. A cutting device in which the cutting blade moves forward with respect to the mold provided with the actuator to cut the surplus portion of the molding material, a suction device capable of decompressing the inside of the cavity, and heating the molding material to a melting point or higher And a cooling means capable of cooling the molding material to a predetermined temperature or less, and an excess portion is cut from the molding material preheated to a temperature higher than the thermal deformation temperature of the thermoplastic resin by the cutting device. To form a cavity that can be closed and decompressed,
The mold is heated up to a temperature higher than the melting point of the molding material in the cavity while the cavity is decompressed by the suction device, and then the molding material is added. Since the pressure is started and cooling of the molding material or the mold is started to be equal to or lower than a certain temperature at the same time before or after the pressing of the molding material is started , the reinforcing fiber is well impregnated with the thermoplastic resin, A molded product in which no voids remain on the surface can be molded .

It is the schematic of the press molding apparatus of the molded article containing the reinforced fiber and thermoplastic resin of this embodiment, Comprising: It is a figure which shows the state which mounted the molding material. It is the schematic of the press molding apparatus of the molded article containing the reinforced fiber and thermoplastic resin of this embodiment, Comprising: It is a figure which shows the state at the time of pressurizing a molding material. It is a top view of the lower mold | type of the press molding apparatus of the molded article containing the reinforced fiber and thermoplastic resin of this embodiment. It is a figure which shows the action | operation of the press molding method of the molded article containing the reinforced fiber and thermoplastic resin of this embodiment.

A press molding apparatus 11 for a molded product containing reinforcing fibers and a thermoplastic resin according to this embodiment will be described with reference to FIGS. The press molding apparatus 11 is a vertical press apparatus that compresses a molding material M containing reinforcing fibers and a thermoplastic resin between an upper mold 12 and a lower mold 13. The press molding apparatus 11 is provided with a movable platen 16 which is an upper plate and to which an upper die 14 is attached, so as to be movable up and down with respect to a fixed platen 15 to which the lower die 13 is attached. Near the four corners of the movable platen 16, compression cylinders 14 are provided. Further, tie bars 17 are fixed in the vicinity of the four corners of the fixed plate 15 in the vertical direction, and the tie bars 17 are inserted and fixed in the center hole of the piston 18 of the compression cylinder 14. The compression cylinder 14 is a backward-acting hydraulic cylinder, and a compression oil chamber 19 and a mold opening oil chamber 20 are formed with a piston 18 in between. The pipes 21 and 22 connected to the compression oil chamber 19 and the mold opening oil chamber 20 are provided with pressure sensors 23 and 24 for measuring the pressure of the hydraulic oil, and the pipes 21 and 22 are connected to the servo valve 25. ing. The servo valve 25 is connected to other valves, pumps, and tanks constituting the hydraulic device 26.

Half nuts 27 are respectively attached around the portion of the upper surface of the movable plate 16 where the tie bar 17 is inserted. The lower surface of the half nut 27 is in contact with the upper surface of the piston 18 of the compression cylinder 14. A mold opening / closing device 28 for connecting the fixed platen 15 and the movable platen 16 to move the movable platen 16 up and down is attached. Here, the mold opening / closing device 28 includes a servo motor 29 and a ball screw mechanism operated by the servo motor 29. There are four mold opening / closing devices 28, and the position (distance) of the movable platen 16 relative to the fixed platen 15 can be measured by the encoder of the servo motor 29. Note that the number of mold opening / closing devices 28 is preferably two or more, and the actuator may be a hydraulic cylinder. The structure of the press molding apparatus 11 is not limited to the above. In the press molding apparatus, the upper board may be a fixed board and the lower board may be a movable board. Further, when a compression cylinder is provided for each tie bar 17, a compression cylinder may be provided on the stationary platen. Further, the half nut may be provided on a panel different from the compression cylinder, or may be of a type in which the sleeve body is pressed against the tie bar 17 by hydraulic pressure or the like and locked. The mold clamping device may be one using a toggle mechanism or one having a compression cylinder ram attached to the back of the movable platen. The mold clamping device may be a combination of a main main compression mechanism and four sub-compression mechanisms that adjust the parallelism between the lower mold and the upper mold.

In this embodiment, the lower mold 13 is fixed to a fixed board 15 which is a lower board and is not described so as to be movable. However, only the lower mold or the lower mold and its holding plate face the outside of the press molding apparatus. A certain bolster may be moved together, or a mold composed of a lower mold and an upper mold may be moved toward the outside of the press molding apparatus. The press molding apparatus 11 is preferably a vertical type in which the movable plate 16 and the upper mold 12 (movable mold) are moved up and down and compressed in the vertical direction when the molding material M is placed. A horizontal type in which the board and the movable mold move in the horizontal direction may be used. However, in that case, a device is required for setting the prepreg which is the molding material M.

Next, the metal mold | die which comprises a part of press molding apparatus 11 is demonstrated. As shown in FIGS. 1 and 2, the lower mold 13 (fixed mold) attached to the stationary platen 15 is a convex mold, and its upper surface is composed of a cavity surface 30 and a surface 31 around the cavity surface 30. Is done. A cutting blade 33 (male blade) of a cutting device 32 is provided between the cavity surface 30 and a surface 31 around the cavity surface so as to be able to be raised and lowered by a hydraulic cylinder as an actuator so as to surround the cavity surface 30. The peripheral surface 31 of the outer cavity surface with the cutting blade 33 as a boundary is an inclined surface that decreases toward the outer side, and the cut surplus portion M3 falls to the outside of the mold. Or you may provide the handling apparatus and conveying apparatus for collect | recovering the surplus parts M3 in the part outside the cutting blade 33. FIG. In the present embodiment, the cutting blade 32 is provided on the entire periphery of the cavity surface 30, but the cutting blade 32 may be provided on only a part of the periphery of the cavity surface 30.

The outer shape of the cavity surface 30 of the lower mold 13 of this embodiment is not a rectangle but a pentagon as shown in FIG. A rib forming portion 34 (concave portion) for forming a rib M2 which is a thick portion in the molded product is provided at the central portion of the cavity surface 30. An ejector device 35 is incorporated in the lower mold 13. The front surface of the protruding member 36 of the ejector device 35 is the bottom surface of the rib forming portion 34 and has a function of compressing the molten resin in the rib forming portion 34. The protruding member 36 may form at least a part of the bottom surface of the rib forming portion 34 or may form the whole. Further, the protruding protruding member 36 and the compression member that compresses the rib forming portion 34 may be different members.

A vacuum suction hole 38 is formed in a portion between the main body portion 37 and the protruding member 36 of the lower mold 13, and the vacuum suction hole 38 decompresses the inside of the cavity through a passage formed in the mold (main body portion 37). It is connected to a vacuum pump 39 which is a possible suction device. It is important that the molten resin does not enter the vacuum suction hole 38, or even if the molten resin enters, there is almost no influence on the molded product, and the vacuum suction hole 38 is closed by the movement of the member such as the protruding member 36. It may be formed from a porous metal. Furthermore, a temperature sensor 40 for measuring the mold temperature is attached to the lower mold 13. The temperature sensor 40 may be one that directly measures the temperature near the cavity surface 30 with a thermocouple or the like, or one that measures the temperature of the temperature control medium or one that directly measures the temperature of the heater. There is no limitation as long as there is. Note that the vacuum suction hole 38, the temperature sensor 40, and the concave portion forming the thick portion may be provided in at least one of the lower mold 13 and the upper mold 12.

The upper mold 12 (movable mold) attached to the movable board 16 which is the upper board is a concave mold, and the lower surface thereof has a cavity surface 41 corresponding to the cavity surface 30 of the lower mold 13 and a surface 42 around the cavity surface. Consists of A hole into which the lower cutting blade 33 is inserted is provided between the cavity surface 41 and the peripheral surface 42 of the cavity surface so as to surround the cavity surface 41, and the inner edge portion of the hole becomes the female blade 43. ing. A seal member is provided on the side surface of the hole and in the vicinity of the female blade 43. When the cutting blade 33 moves forward, the sealing member comes into contact with the side surface of the cutting blade 33 so that the cavity is sealed. It should be noted that the cavity sealing structure may be another structure, such as one that seals when the upper mold 12 is lowered.

Position sensors 44 for measuring the distance (distance) between the lower mold 13 (fixed mold) and the upper mold 12 (movable mold) are mounted near the four corners of the lower mold 13 and the upper mold 12, respectively. The type of the position sensor 44 is not limited, and the sensor body may be attached to either the lower mold 13 side or the upper mold 12 side. A temperature control medium flow path 45 is provided in the vicinity of the cavity surfaces 30 and 41 inside the lower mold 13 and the upper mold 12. The flow path 45 of the temperature control medium is connected to a heating medium supply device 46 that is a heating means and a cooling medium supply device 47 that is a cooling means, so that the temperature of the lower mold 13 and the upper mold 12 can be changed to the melting point of the molding material M. The heating means that can be heated and the cooling means that can cool the molding material to a certain temperature or less are configured. The heating means for the mold is not limited to the above, but may be one using an electric heater, an induction heating device, a steam heating device, or the like.

The shape of the cavity surfaces 30 and 41 is not limited to the above because it differs depending on the shape of the molded product. The upper mold 12 may be a convex mold and the lower mold 13 may be a concave mold, or both molds may be flat plate molds (including those having fine irregularities). Also, the thick part forming part (rib forming part 34) is not for forming a rib, but a thick part of a molded product in which the thickness gradually differs between the thick part and the thin part. It may be for doing. The molded product may have a more complicated shape such as a hole or a flat plate. When molding a molded product having a complicated shape, the mold is provided with a movable core or the like. May be good.

Next, the control apparatus 48 which comprises a part of press molding apparatus 11 is demonstrated. The control device 48 is a concept including a servo amplifier for controlling the servo motor 29 for opening and closing the mold, and is also connected to the servo motor 29 (including an encoder). The control device 48 is also connected to each valve of the hydraulic device 26 that drives the press molding device 11. The control device 48 is provided in a temperature control medium supply device such as a position sensor 44 and a temperature sensor 40 attached to the mold, a heating medium supply device 46 and a cooling medium supply device 47, and a flow path 45 of the temperature control medium. It is also connected to a valve or the like. The control device 48 is also connected to peripheral devices such as a vacuum pump 39 and an unillustrated unloader.

Next, a method for press-molding a molded product including the reinforcing fiber and the thermoplastic resin using the press molding apparatus 11 for the molded product including the reinforcing fiber and the thermoplastic resin according to the present embodiment will be described. The molding material used in the present embodiment is a prepreg using carbon fibers as the reinforcing fibers and polyamide (PA6) as the thermoplastic resin matrix resin which is a matrix resin. Note that the molding material may be a combination of at least two of the prepreg M, the reinforcing fiber-only sheet, and the resin-only sheet.

As shown in FIG. 4, the molding material is set on the cavity surface 30 of the lower mold 13 in the first placement process. At this time, if there is a thick part forming part such as the rib forming part 34, a molding material for the rib M2 (molding material for the thick part) is inserted into the rib forming part 34 (concave part). The molding material for the rib M2 is formed from an excessive portion M3 obtained by cutting a rectangular prepreg M in accordance with the shape of the periphery of the molded product at the time of molding up to the previous time. In manufacturing the material for the rib M2 from the surplus portion M3 in the present embodiment, the material is once pulverized and then pressed with a separate mold according to the shape of the rib M2. However, the finely pulverized material may be directly pushed into the rib forming portion 34, or may be cut and laminated according to the shape of the rib without pulverizing the prepreg M. Alternatively, the molding material for the rib M2 may be injection molded using a finely pulverized material. Further, the molding material for the prepreg M and the rib M2 (molding material for the thick portion) is joined by heat melting or the like outside the press molding apparatus 11 and placed on the cavity surface 30 of the lower mold 13. May be. When the thick part of the molded product has a certain area or more, one or more prepregs M cut in accordance with the shape of the thick part are used in piles. In addition, if the molded product is a flat plate with no thick part and thin part, or if the difference in thickness between the thick part and the thin part is less than a predetermined value, only the prepreg M of the same shape is stacked. May be used as a molding material.

Next, the rectangular prepreg M, which is a molding material, is placed on the cavity surface 30 of the lower mold 13 (fixed mold) of the press molding apparatus 11. At this time, as shown in FIG. 4, the lower mold 13 and the upper mold 12 are heated to a temperature not lower than the heat distortion temperature of the matrix resin (thermoplastic resin) contained in the prepreg M and not higher than the melting point. Is desirable. Further, the prepreg M itself is transported in a state in which the temperature is raised to a temperature higher than the heat deformation temperature of the matrix resin (more desirably, a melting point temperature minus 50 ° C. or more) by a preheating device such as an infrared heating device (not shown) outside the press molding device 11. It is desirable to place it on the lower mold 13 using an apparatus. If the shape is maintained by the reinforcing fibers even when the matrix resin is melted and there is no hindrance to the conveyance of the prepreg M, the matrix resin may be heated to a temperature equal to or higher than the melting point of the matrix resin. The temperature of the lower mold 13 and the upper mold 12 may be raised to the melting point of the matrix resin or higher when the prepreg M is placed depending on the shape of the cavity and the type of the matrix resin.

In the present embodiment, a molding material in which only a plurality of prepregs M (two to thirty as an example, but not limited thereto) are used is used. At this time, in the case where the reinforcing fibers of the prepreg M are oriented in only one direction, it is desirable that the reinforcing fibers of the prepreg M are stacked so that the directions of the reinforcing fibers are orthogonal to each other. When the rectangular prepreg M is placed on the cavity surface 30 of the lower mold 13, the area of the prepreg M is larger than the area of the cavity surface 30 so that the prepreg M protrudes from the entire periphery of the cavity surface 30. Is done. At this time, the prepreg M does not have an area covering the entire cavity surface 30 but may cover the cavity surface 30 with two or more prepregs M placed side by side in the horizontal direction. As described above, the prepreg M placed on the cavity surface 30 is preheated, and the temperature of the lower mold 13 is also heated at least to the heat deformation temperature. The planar prepreg M is also deformed into a shape substantially following the shape of the cavity surface 30.

Next, the movable platen 16 and the upper mold 12 are lowered, and the cavity surface 41 of the upper mold 12 is brought into contact with the upper surface of the prepreg M. The operation control of the movable platen 16 at this time is performed by speed control (or position control), and when it reaches a predetermined position, the movable platen 16 is stopped by position control (the mold closing process in FIG. 4). The stop position at this time is a position where the prepreg M can be further shaped to follow the shape of the molded product, but is a position where a sufficient pressure is not yet applied to the prepreg M. This position is preferably a preset position. However, it is detected that the torque of the servo motor 29 for opening / closing the mold has increased due to the upper mold 12 coming into contact with the prepreg M, or the mold opening / closing cylinder is used. For example, the movable platen 16 may be stopped by detecting an increase in pressure.

In the next cutting step, the hydraulic cylinder, which is the actuator of the cutting device 32, is operated to advance the cutting blade 33, and the excess portion M2 protruding from the cavity surface 30 of the prepreg M is cut off. At this time, the prepreg M is preheated (desirably higher than the heat distortion temperature, more preferably preheated to the melting point temperature minus 50 ° C. or higher), so that the cutting blade 33 can be easily cut. Less wear. It is desirable that the cutting blade 33 has a structure in which the cutting edge is attached in an oblique direction rather than a direct direction with respect to the ascending / descending direction of the cutting blade 33 so that all the cutting edges do not contact the prepreg M at the same time. Further, the cutting device 32 may be one in which a cutting blade is provided on the upper mold 12 (movable mold) and the surplus portion M2 is cut by the lowering of the upper mold 12. In the present embodiment, the cut surplus portion M2 slides down the surface 31 (inclined surface) around the cavity surface and is collected in a collection tray (not shown) provided around the press molding apparatus 11. Note that the robot may be used to grip and collect the surplus portion M2.

When the surplus portion M2 is cut by the cutting blade 33 of the cutting device 32, the portion of the cutting blade 33 is sealed by the sealing member, and the molding portion M1 cut into the shape of the molded product of the prepreg M is isolated from the outside world. It is stored in the cavity. A passage including a suction hole 37 connected to the cavity is communicated from the vacuum pump 39 operated in this state, and air is sucked in order to decompress the inside of the cavity. The cavity may be sealed only by lowering the upper mold 12 and isolated from the outside. Alternatively, the entire press molding apparatus 11 may be placed in a vacuum chamber and the cavity may be isolated from the outside. In the next pre-pressurization step, the temperature of the lower mold 13 and the upper mold 12 is raised before and after the atmospheric suction in the cavity, and the temperature of the molding part M1 is equal to or higher than the melting point of the thermoplastic resin included in the prepreg M. Raise to temperature. The mold temperature at this time detects the temperature of the temperature sensor 40 and controls the heating medium supply device 46 in a closed loop. However, only the heat medium temperature of the heating medium supply device 46 outside the mold may be measured to perform closed loop control, and the mold temperature may not be used for control.

At this time, if the suction hole 38 is exposed to the cavity, the mold temperature can be raised to the melting point or higher after the atmospheric suction (decompression or evacuation) in the cavity by the vacuum pump 39 is stopped. desirable. However, if the structure of the suction hole 38 is special, it may be considered that the decompression in the cavity is stopped after the mold temperature is raised to the melting point or higher, and gas is generated when the matrix resin is melted. It is effective when it becomes. As an example, when the matrix resin is PA6, the temperature is raised to 225 ° C. or higher, which is the melting point of PA6. The range of the temperature rise is not limited to this, but it is desirable that the mold temperature be in the range of the melting point or higher and the melting point plus 40 ° C. or lower. When induction heating or the like is used as the heating means, only the temperature of the prepreg M, which is the molding material, is raised to the melting point of the matrix resin or higher.

The temperature rising process in which the mold temperature or the temperature of the molding material is increased from the mold contact to the melting point of the matrix resin of the molding material, or the impregnation is promoted after the mold temperature or the molding material temperature exceeds the melting point. In the impregnation process (the pre-pressurization process in FIG. 4 together with both), in the case where the lower mold 13 and the upper mold 12 are provided with vibration applying devices such as vibrations, by applying vibration to the mold It is possible to promote good air removal and impregnation of matrix resin into reinforcing fibers such as carbon fibers. Alternatively, the mold opening / closing device is operated by speed control or position control to move the upper mold 13 (movable mold) in the opening / closing direction, so that a space between the prepregs M in the cavity (resin-only sheet or reinforcing-fiber-only sheet is present). (Including the case where it is inserted) and the impregnation of the resin into the reinforcing fiber may be promoted. Further, at this time, the ejector device 35 may be operated to partially apply force to the prepreg M in the cavity to promote air removal or resin impregnation.

When a predetermined time elapses after contact with the mold contact position (or when a predetermined time elapses after the molds 12 and 13 reach a temperature equal to or higher than the melting point), a pressurizing step (first pressurizing step) is performed. Start. In the first pressurizing step, the compression cylinder 14 is operated, and the movable platen 16 and the upper mold 12 (movable mold) are further lowered by position control (or speed control). At this time, it is desirable that the temperature of the mold or prepreg M is higher than the melting point at the start of pressurization, but the temperature of the prepreg M or mold as the molding material is higher than the melting point of the resin of the prepreg M in the reduced pressure cavity. If pressurization of the prepreg M is started after being held in a heated state, excluding those in which pressurization is started after the mold or prepreg M is cooled to a temperature slightly lower than the melting point. Absent.

The half nut 27 is appropriately operated during the period from the start of mold contact until the predetermined time elapses, and is engaged with the groove of the tie bar 17. At this time, the cooling medium is circulated through the flow path 45 from the cooling medium supply device 47 as the cooling means at the same time as or after the lowering control of the upper mold 12, and cooling of the molds 12 and 13 is started. Regarding the position control at this time, the values of the four position sensors 44 arranged between the molds 12 and 13 or the base plates 15 and 16 are detected, and the values of the position sensors 44 (values from the origin) are the same. Only the speed control (or position control) is performed by the compression cylinders 14 corresponding to the respective position sensors 44 so that the value becomes a value, and the parallelism of the upper mold 12 (or the movable platen 16) with respect to the lower mold 13 (or the fixed platen 15). Parallel control is performed so that is maintained.

In the present embodiment, the shape of the molded product is not a rectangle, and the center of gravity when the molded product is viewed in plan and the center of gravity of the press molding apparatus 11 (the intersection of lines connecting the compression cylinders 14 between diagonals) are one. I have not done it. Therefore, even if the four compression cylinders 14 are controlled with the same pressure to compress the prepreg M as a molding material, the parallelism of the upper mold 16 with respect to the lower mold 15 is different. That is, when each compression cylinder 14 is pressurized and controlled with the same pressure, the surface pressure relative to the molded product is relatively high on the side where the area of the molded product is small when viewed from the center of gravity, and the movable platen is pressed by excessively pressing the compression cylinder 14. The amount of advance of 16 and the upper mold | type 12 will become relatively large. Further, on the side where the area of the molded product is large as viewed from the position of the center of gravity, the surface pressure against the molded product is relatively low, and the advancement amount of the movable platen 16 and the upper mold 12 is relatively small due to insufficient pressing of the compression cylinder 14. End up. Further, the deviation in parallelism during the pressurization control becomes more prominent as the temperature of the matrix resin of the prepreg M is higher and the fluidity is higher.

There are various parallel control (closed loop control) performed by detecting the value of the position sensor 44, and the speed control (or position control) is performed by the servo valve 25 using the single-axis compression cylinder 14 as a master cylinder. The other compression cylinders 14 may control the servo valves 25 provided corresponding to the respective compression cylinders 14 by following the master cylinders as slave cylinders. Alternatively, a speed control method (or position control) is performed to individually control servo valves 25 provided corresponding to each compression cylinder 14 so that the average position of each compression cylinder 14 reaches the target position. Method). In the latter case, the control signal is generated by obtaining the difference between the target position and the detection position of each position sensor, and the feedback control is performed by controlling each servo valve 25 of each compression cylinder 14. In both the former and the latter, the original pressure sent from the pump to each compression cylinder 14 is controlled to the set pressure.

The mold temperature of the lower mold 13 and the upper mold 12 is a predetermined temperature which is not higher than the melting point and is not lower than the heat distortion temperature (although not limited to this, preferably in the range of melting point minus 5 ° C. to melting point minus 50 ° C.) When the temperature sensor 40 detects that it has become, the control by the compression cylinder 14 is switched from only speed control (or only position control) to control that adds pressure control elements. Note that the temperature of the temperature control medium may also be detected as the mold temperature at this time. In the present embodiment, the control can be changed at a stage where the fluidity of the resin is optimal by switching the control depending on the temperature. Then, the control of the compression cylinder 14 is switched from the first pressurizing process of only speed control (or only position control) to the second pressurizing process using both speed control (position control) and pressure control. In this case as well, the speed control (position control) element may use a method of matching the position of the other compression cylinder 14 (detected by the position sensor 44) with the compression cylinder 14 of the master shaft. A control method may be used in which the position of each compression cylinder 14 (detected by the position sensor 44) reaches the target position of the average value.

For pressure control, the pressure of the hydraulic oil in the compression oil chamber 19 of the compression cylinder 14 is detected by the pressure sensor 23, and the average value is calculated and used for the control. Then, a difference from the target pressure is taken to generate a control signal for the pressure loop. Accordingly, the same advance amount command is issued to each compression cylinder 14. The target pressure at this time is not limited to this. For example, the hydraulic pressure of the hydraulic oil may be determined so that the surface pressure exerted on the molded product is 3 to 30 MPa (more preferably 5 to 20 MPa). desirable. In this pressure control, the pressure of the hydraulic oil in the mold opening oil chamber 20 may also be detected by the pressure sensor 24 and used for the control. Then, the control signal of the advance amount by the pressure loop is added to the control signal by the speed loop (or position loop) and used in the second pressurizing step of compression molding. As for the pressure control, the servo valve 25 may be individually controlled for each compression cylinder 14 so that the value of each pressure sensor 23 becomes the target pressure. Also in this case, an element of speed control (position control) is added to the control signal for pressure control of the individual compression cylinder 14 and used for compression molding.

Therefore, in the second pressurizing step of compression molding of this embodiment, the pressure control of each compression cylinder 14 can be performed while ensuring the parallelism of the movable platen 16 with respect to the fixed platen 15 by speed control (position control). The parallelism can be ensured even for a molded product having a problem in fluidity, or a molded product having a non-uniform shape and a portion that is easily compressed and a portion that is difficult to be compressed.

During the second pressurizing step, the mold temperature is maintained at a set target cooling temperature not higher than the heat distortion temperature. The mold is cooled by the cooling means by detecting the temperature by the temperature sensor 40, but only the cooling heat medium temperature of the cooling medium supply device 47 outside the mold is measured to perform closed loop control, and the mold temperature is controlled. You may not use it. When a predetermined time elapses from the start time of the second pressurizing process, the second pressurizing process is finished, the pressure of the compression cylinder 14 is released, and then the compression cylinder 14 is operated to the mold opening side to release the mold. I do. (Or the end of the second pressurizing step may be performed by another time measurement or the like.) At this time, the matrix resin of the molded product has a resin cavity solidification temperature at which the cavity surfaces 30 and 41 of the mold are below the heat deformation temperature. Since it is sufficiently cooled by being kept cooled, it can be released satisfactorily. Then, the upper mold 12 is moved to the mold opening position by the mold opening / closing device 28 (mold release / mold opening process in FIG. 4). Further, the molded product remaining in the lower mold 13 is ejected by the ejector device 35 (projecting step in FIG. 4). Further, the upper mold 12 and the lower mold 13 are switched to heating control by the heating means at the same time as or before and after the protrusion of the molded product by the ejector device 35. It is desirable that the cutting blade 33 is retracted when the molded product is ejected.

In the present embodiment, the bottom surface of the rib forming portion 34 is formed by the protruding member 36 of the ejector device 35 and can be moved by the hydraulic cylinder of the ejector device 35. Therefore, the first pressurizing step and the second pressurizing step are performed. You may make it compress the rib formation part 34 (thick part) by operating a hydraulic cylinder between at least one pressurization process. As a result, the density of the rib part M2 and the main body part M1 becomes substantially equal, and the strength with which the rib part M2 adheres to the main body part M1 is improved.

In addition, the set temperature of the mold in the second pressurizing step is desirably equal to or lower than the thermal deformation temperature of the matrix resin of the prepreg M to be molded. It is sufficient if it is below a certain temperature at which the mold can be formed. Further, a molded product taken out from the mold may be taken out at a temperature higher than the heat deformation temperature even if the set temperature of the mold is equal to or lower than the heat deformation temperature.

In this embodiment, the temperature sensor 40 sets the mold temperature to the set temperature by switching from the pre-pressurization process to the first pressurization process and from the first pressurization process to the second pressurization process. It is detected and detected. However, the process may be switched by detecting that the oil pressure of the compression cylinder 14 has reached the set pressure by the pressure sensor 23 and switching at least one process or switching at least one process only by the passage of time. Alternatively, the process may be switched when both the mold temperature and the hydraulic pressure of the compression cylinder 14 reach predetermined set values. Further, at this time, instead of the hydraulic pressure of the compression cylinder 14, the mold clamping force or the cavity internal pressure (surface pressure) measured by a tie bar sensor or the like may be measured and used for control.

Furthermore, the present invention detects, after the second pressurization step, that the mold temperature has become a predetermined temperature or the pressure of the compression cylinder 14, and performs pressure control as the third pressurization step. May only do. When the compression cylinder 14 is controlled only by pressure control, the servo valve 25 is controlled so that the pressure in the compression oil chamber 19 of each compression cylinder 14 reaches the target pressure, thereby equalizing the pressure. Pressure becomes possible. Alternatively, the target pressure may be individually determined and controlled for each compression cylinder 14. Furthermore, the first pressurization process may be directly shifted from the speed control (or position control) to the third pressurization process with only pressure control.

The present invention is not enumerated one by one, but is not limited to that of the above-described embodiment, and it goes without saying that those skilled in the art also apply modifications made in accordance with the spirit of the present invention. is there. The reinforcing fiber used in the present invention is not limited to carbon fiber, and may be glass fiber or the like. The thermoplastic resin used in the present invention is not limited to polyamide (PA6), and may be polyamide (PA66), polycarbonate, polypropylene, or the like, or may contain a thermosetting resin. The form of the molding material supplied to the press molding apparatus 11 is not limited to the prepreg alone, and may include at least two of the prepreg, the resin-only sheet, and the reinforcing fiber-only sheet. That is, a sheet of reinforcing fiber only and a sheet of resin only may be laminated and placed on the cavity surface 30 of the lower mold 13 and press molded. And about a thermoplastic resin, what was already made into the molten state with the heating supply apparatus of the previous process may be supplied. In this case, the thermoplastic resin in the molten state may be supplied in a state where the sheet of the reinforcing fiber only is placed on the cavity surface 30 of the lower mold 13, or the thermoplastic resin containing the reinforcing fiber is supplied in the molten state. Also good.

11 Press molding device 12 Upper mold 13 Lower mold
14 Compression cylinders 23 and 24 Pressure sensor 25 Servo valves 30 and 41 Cavity surface 33 Cutting device 35 Ejector device 39 Vacuum pump (suction device)
40 Temperature sensor 44 Position sensor 46 Heating medium supply device (heating means)
47 Cooling medium supply device (cooling means)
48 Controller M Prepreg (molding material)
M1 body part M2 rib forming part M3 surplus part

Claims (5)

In press molding equipment for molded products containing reinforcing fibers and thermoplastic resin,
A mold in which a cavity for molding a molding material is formed between a fixed mold and a movable mold;
A cutting device in which the cutting blade advances with respect to the mold provided with the actuator to cut the surplus portion of the molding material by the operation of the actuator ;
A suction device capable of depressurizing the cavity;
Heating means capable of heating the molding material to a melting point or higher;
Cooling means capable of cooling the molding material to a certain temperature or less, and
A cavity that can be closed and depressurized is formed by cutting the surplus portion from the molding material preheated to a temperature higher than the thermal deformation temperature of the thermoplastic resin by the cutting device,
While making the cavity into a decompressed state by a suction device,
Pressurizing the molding material after heating the mold and setting the temperature of the molding material or the mold in the cavity above the melting point of the molding material,
An apparatus for press-molding a molded article containing reinforcing fibers and a thermoplastic resin, wherein cooling of the molding material or the mold is started to a certain temperature or less at the same time as or after the start of pressurization of the molding material. The mold consists of an upper mold and a lower mold,
The temperature of the upper mold and the lower mold when placing the preheated molding material on the lower mold is a temperature not lower than the melting point and not higher than the melting point of the thermoplastic resin of the molding material,
Molded article of press molding comprising reinforcing fibers and a thermoplastic resin according to claim 1, characterized in that pressure can be reduced cavity is closed is formed by the surplus portion is cut from the molding material by said cutting device apparatus. In the press molding method of a molded product containing reinforcing fiber and thermoplastic resin,
Insert a molding material containing reinforcing fiber and thermoplastic resin into the cavity formed between the fixed mold and movable mold,
While cutting the surplus portion from the molding material preheated to a temperature higher than the thermal deformation temperature of the thermoplastic resin by a cutting device,
The movable mold is closed by speed control or position control to form a closed cavity,
While sucking the atmosphere in the cavity with a suction device and making it in a reduced pressure state, the mold is heated by the heating means so that the temperature of the molding material or the mold is heated above the melting point of the molding material,
A method for press-molding a molded article containing reinforcing fibers and a thermoplastic resin, wherein cooling of the molding material or the mold is started to a certain temperature or less at the same time as or after the start of pressurization of the molding material. While maintaining the state of forming a closed cavity,
4. A molded article comprising reinforcing fibers and a thermoplastic resin according to claim 3, wherein the movable mold is moved in the opening / closing direction, or vibration is applied to at least one of the fixed mold and the movable mold. Press molding method. The thermoplastic resin molded product containing the reinforcing fiber has a thick portion,
At least one of the fixed mold and the movable mold includes a thick part forming part for forming the thick part,
The molding material formed from the surplus portion cut by the cutting device is inserted into the thick portion forming portion and the molding material in the thick portion forming portion is pressurized. Item 5. A method for press-molding a molded article comprising the reinforcing fiber according to Item 4 and a thermoplastic resin.

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