JP2008073910A - Molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive molding machine in which a plurality of slide molds can be pressed by uniform pressing force. <P>SOLUTION: The molding machine 31 molding a foamed resin molding has a plurality of slide molds 45 which are installed in a fixed mold 43 and keep the volume of part of a corresponding cavity 61 constant by pressing a movable mold 41 when the movable mold 41 retreats. The molding machine 31 is provided additionally with a movable plate 49 on which the slide molds 45 are set to be separated from each other, a plurality of coil springs 53 (elastic members) which are supported by fixed bodies 55 and 57 in order to press the slide molds 45 and energize the movable plate 49 in the press direction, and a plurality of liquid pressure cylinders 51. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a molding apparatus for molding a foamed resin molding by enlarging the cavity volume of a molding die having a fixed die and a movable die.

  2. Description of the Related Art Conventionally, foamed resin moldings that are molded by foaming a thermoplastic resin are known. This foamed resin molded body is formed by filling the cavity of a mold having a fixed mold and a movable mold with a thermoplastic resin, and then retreating the movable mold to expand the cavity volume, thereby forming the surface. And a swelling layer having a resin density lower than that of the skin layer and having a large number of voids. Thereby, compared with the case where the surface and the inside are both formed with the same resin density as the skin layer, the weight reduction of the resin molding can be achieved.

On the other hand, as shown in Patent Document 1, in a molding apparatus for a foamed resin molded body, a slide mold is provided in a mold, and when the cavity volume is enlarged, the slide mold is slid in conjunction with the retraction of the movable mold to face the mold. A structure is known in which the cavity volume of the corresponding part of the slide mold is kept constant by pressing against the mold surface. A hydraulic cylinder and a spring member are shown as a mechanism for pressing the slide mold.
JP 2006-76124 A

  By the way, when using a resin molded object, the part to which local stress is added may be required like the attachment part used as the attachment part with the other member of a resin molded object, for example. Since such a portion is subjected to a higher stress than other portions, it is necessary to make it a high strength portion having a partially high strength.

  Therefore, for example, as in the molding apparatus shown in Patent Document 1, even when the cavity volume is expanded, the cavity thickness of the corresponding part of the slide mold is kept constant so that the part is a solid layer having a resin density higher than that of the expanded layer. It is considered that the solid layer is formed as a high-strength portion.

  Then, when a plurality of slide dies are arranged in the mold and these slide dies are to be pressed by one movable plate, it is conceivable that the movable plate is biased by a plurality of hydraulic cylinders or the like.

  However, when a hydraulic cylinder is used, the urging force of each hydraulic cylinder may be different due to an attachment error of the plurality of hydraulic cylinders. If it does so, the movable plate cannot be urged | biased by the uniform urging | biasing force as a whole, and there exists a problem that a movable plate will twist by the imbalance of urging | biasing force, and a several slide type | mold cannot be pressed with uniform pressing force. In addition, although the hydraulic cylinder is advantageous in that its pressing force is stable, it is expensive, and if it is attempted to suppress the twist of the movable plate by increasing its number, the molding apparatus becomes expensive. There is also a problem.

  On the other hand, a structure in which the movable plate is urged by a spring member is also conceivable, but the spring member is advantageous in that it is less expensive than the hydraulic cylinder, but the pressing force is not stable and is the same as that of the hydraulic cylinder. In addition, the movable plate cannot be biased by a uniform biasing force.

  This invention is made | formed in view of this point, The place made into the objective is to provide the cheap shaping | molding apparatus which can press a some slide type | mold with a uniform pressing force.

  In order to solve the above problems, in the molding apparatus according to the present invention, the movable plate provided with a plurality of slide molds is urged by a plurality of hydraulic cylinders and a plurality of elastic members.

  Specifically, the molding apparatus according to the first invention fills a cavity of a molding die having a fixed die and a movable die arranged to face the fixed die, and retracts the movable die. A molding apparatus for molding a foamed resin molded body by enlarging the cavity volume, and is provided in one of the fixed mold or the movable mold, and when the movable mold is retracted, the other of the fixed mold or the movable mold is In order to press the plurality of slide molds that hold a certain volume of the corresponding cavity constant by pressing, a movable plate in which the plurality of slide molds are spaced apart from each other, and the slide mold And a plurality of elastic members and a plurality of hydraulic cylinders that are supported by the fixed body and bias the movable plate in the pressing direction.

  A molding apparatus according to a second aspect of the present invention is the molding apparatus according to the first aspect of the present invention, wherein the fixed body is composed of a first fixed body that supports the elastic member and a second fixed body that supports the hydraulic cylinder. The first fixed body is disposed closer to the movable plate than the second fixed body.

  According to the first aspect of the invention, by using a plurality of hydraulic cylinders with stable pressing force and a plurality of inexpensive elastic members, and energizing the movable plate with them, the mounting accuracy of the plurality of hydraulic cylinders is achieved. Even if they are different, the location where the urging force of the hydraulic cylinder is insufficient can be compensated by the elastic member, and the movable plate is evenly urged without distorting and pressing multiple slide dies with uniform pressing force Can do.

  In addition, the movable plate is not urged only by an expensive hydraulic cylinder, but a hydraulic cylinder and an inexpensive elastic member are used together. It can be made cheap.

  According to the second aspect of the invention, the hydraulic cylinder and the elastic member are supported by separate fixed bodies, and the first fixed body that supports the elastic member is made a movable plate rather than the second fixed body that supports the hydraulic cylinder. Since it has been arranged at a close position, the elastic member can have a short free length. That is, since the hydraulic cylinder is generally a longer device than the elastic member, if the hydraulic cylinder and the elastic member are supported by the same fixed body, the elastic member does not have the same length as the hydraulic cylinder. The movable plate cannot be stably pressed. However, the elastic member can be shortened by supporting the elastic member on the first fixed body that is closer to the movable plate than the second fixed body that supports the hydraulic cylinder, thereby stabilizing the movable plate. And the material cost can be reduced, so that the molding apparatus can be made more accurate and inexpensive.

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

(Side door)
In FIG. 1, reference numeral 1 denotes a front side door of an automobile. The front side door 1 includes a door body 3 having a metal door outer panel 5 and a door inner panel 7. The door inner panel 7 is attached with a door module panel 9 formed by a forming apparatus 31 described later according to an embodiment of the present invention and a door trim 11 that covers the door module panel 9 from the vehicle interior side. ing.

(Door module panel)
FIG. 2 is a view of the door module panel 9 as seen from the outside of the passenger compartment. The door module panel 9 includes a plate-shaped foamed resin molded body formed of a thermoplastic resin containing fibers. The door module panel 9 includes a panel body 15 that forms the main body, a plurality of attachment portions 19 that are attachment locations of the door inner panel 7, and front and rear guide rails (not shown) for raising and lowering the window glass. And a fastening portion 25 for mounting. The panel body 15 and the door inner panel 7 are sealed by a sealing material 13 (shown only in FIG. 1) at the outer peripheral edge of the outer surface of the vehicle body of the panel body 15. The mounting portion 19 is formed on the inner peripheral side of the sealing portion of the panel main body 15 by the sealing material 13. Bolt insertion holes 19a are formed in the mounting portions 19 so as to penetrate through the mounting portions 19. The bolt insertion holes 19a are aligned with corresponding mounting holes 7a (shown only in FIG. 1) of the door inner panel 7, The door module panel 9 is attached to the door inner panel 7 by screwing bolts 21 in advance to the weld nut 23 welded to the inner side of the inner panel 7.

  Further, four fastening portions 25 are formed at positions inside the attachment portion 19 of the panel main body 15. Each of these fastening portions 25 is formed with a bolt insertion hole 25a therethrough. The mounting portion 19 and the fastening portion 25 are formed so as to protrude stepwise from the panel body 15 toward the outside of the passenger compartment.

  The panel main body 15 has a hard skin layer 33 having no voids and a high resin density, and is formed inside the skin layer 33 and has a large number of voids (not shown). It consists of an expanded layer 35 with a low resin density.

  On the other hand, each of the mounting portion 19 and the fastening portion 25 is constituted by a solid layer 37 having a high resin density without the expansion layer 35.

(Molding equipment)
3 and 4 show a molding apparatus 31 according to an embodiment of the present invention that molds the door module panel 9 as a pair. The molding device 31 is slidable on the fixed die 43 shown in the center of the left and right in FIG. 3, a movable die 41 that is opposed to the fixed die 43 so as to be movable back and forth in the left and right directions in FIG. A substantially rectangular forming die 47 having a plurality of slide dies 45 provided on the same is provided. The movable mold 41 has a movable mold side molding surface 41a having a shape corresponding to the shape of the door module panel 9 on the outside of the vehicle compartment, and the fixed mold 43 has a shape corresponding to the shape of the door module panel 9 on the vehicle interior side. Fixed mold side molding surfaces 43a are respectively formed.

  On the other hand, the slide molds 45 are for molding the mounting portions 19 and the fastening portions 25 of the door module panel 9 and are slidably inserted into through holes 43b formed through the fixed mold 43. The number corresponding to the number of the attachment portions 19 and the fastening portions 25 is provided. A slide mold side molding surface 45 a having a shape corresponding to the shape of the mounting portion 19 or the fastening portion 25 on the vehicle interior side is formed on the slide mold 45, and on the movable mold side molding surface 41 a of the movable mold 41, Opposing portions are formed in a recessed shape corresponding to the shape of the mounting portion 19 or the fastening portion 25 outside the passenger compartment. Further, a cylindrical projection 45b for molding the bolt insertion holes 19a, 25a of the mounting portion 19 or the fastening portion 25 is formed at the center of the slide mold side molding surface 45a of the slide die 45, and this projection The tip surface of 45b is in contact with the movable mold side molding surface 41a.

  The plurality of slide dies 45 are erected with a base end portion attached to one substantially rectangular movable plate 49 located on the back side of the fixed die 43 (opposite the movable die 41). The movable plate 49 is spaced apart from the back side of the fixed die 43 and is urged toward the forming die 47 by both a plurality of hydraulic cylinders 51 such as hydraulic cylinders and a plurality of coil springs 53 as elastic members. Due to this urging force, the plurality of slide dies 45 supported (standing) on the movable plate 49 move toward the movable die 41 in a state where the tip surfaces of the projections 45b are in contact with the movable die-side molding surface 41a. It is pressed.

  Specifically, the movable plate 49 supports the tips of the piston rods 51 a of the plurality of hydraulic cylinders 51 and the tips of the plurality of coil springs 53. On the opposite side of the movable plate 49 from the molding die 47, a plate-shaped first fixed body 55 having a substantially rectangular shape in plan view is fixedly disposed apart from the movable plate 49. The base end of the coil spring 53 is supported. Further, on the opposite side of the first fixed body 55 from the movable plate 49, a plate-shaped second fixed body 57 having a substantially rectangular shape in plan view is fixedly disposed apart from the first fixed body 55. This second fixed The body 57 supports the base side of the hydraulic cylinder 51. The first and second fixed bodies 55 and 57 are integrally connected by a connecting means (not shown) and fixed so as not to move relative to the fixed mold 43. The first fixed body 55 has a cylinder insertion hole (not shown) that allows the hydraulic cylinder 51 to pass therethrough. As described above, the coil spring 53 is supported by the first fixed body 55 and the hydraulic cylinder 51 is supported by the second fixed body 57, so that the coil spring 53 and the hydraulic cylinder 51 form the movable plate 49 into a mold. It is energized to the 47 side. The slide mold 45 erected on the movable plate 49 abuts the distal end surface of the projection 45b on the movable mold-side molding surface 41a of the movable mold 41, so that the slide mold 45 is connected to the movable mold 41. The inside of the through hole 43b of the fixed mold 43 slides following the advance and retreat with respect to the fixed mold 43.

  FIG. 5 is a plan view of the molding device 31 as viewed from the second fixed body 57 side. With the molding device 31, two door module panels 9 can be molded as indicated by phantom lines in the figure. It is like that. A plurality (four in the illustrated example) of the hydraulic cylinders 51 are arranged at substantially the center of each rectangular edge of the second fixed body 57, as indicated by broken lines in the figure. A plurality (16 in the illustrated example) of coil springs 53 are arranged at intervals so as not to overlap with the positions of the hydraulic cylinders 51 as indicated by broken lines in the figure. Specifically, the hydraulic cylinder 51 and the coil spring 53 are arranged substantially point-symmetrically with respect to the center of the rectangle in the plan view of the mold 47 and the movable plate 49, respectively. As a result, the hydraulic cylinder 51 and the coil spring 53 urge the movable plate 49 evenly.

(Molding method)
Next, a method for forming the door module panel 9 using the forming apparatus 31 according to the embodiment of the present invention will be described.

  First, the movable mold 41 moves forward in the right direction in FIGS. 3 and 4 toward the fixed mold 43 and the mold 47 is closed. At this time, the slide mold 45 is pushed by the movable mold 41 with the protrusion 45b that is in contact with the movable mold-side molding surface 41a of the movable mold 41, and follows the advance of the movable mold 41. Slide in 43b. As the slide mold 45 slides, the movable plate 49 moves toward the first and second fixed bodies 55 and 57 while contracting them against the urging force of the hydraulic cylinder 51 and the coil spring 53. As a result, the movable plate 49 is urged toward the forming die 47 by the plurality of hydraulic cylinders 51 and the coil springs 53, and the plurality of slide dies 45 press the movable die 41 by the movable plate 49.

  Next, the thermoplastic resin R containing fibers is injected and filled into the cavity 61 of the mold 47 from an injection machine (not shown).

  Thereafter, in the process in which the thermoplastic resin R is solidified in the cavity 61 of the mold 47, the movable mold 41 is retracted in the mold opening direction (the arrow direction in FIG. 4) in which the volume of the cavity 61 is increased. In other words, the movable mold 41 moves backward to move away from the fixed mold 43, and the cavity volume is increased to twice or more, for example. The process of solidifying the thermoplastic resin R is when the skin layer 33 is generated in the vicinity of the molding surfaces 41 a and 43 a of the molding die 47 (movable die 41 and fixed die 43) in the cavity 61.

  As the movable mold 41 moves backward, the movable plate 49 pressed by the hydraulic cylinder 51 and the coil spring 53 follows the molding mold 47 side, so that the plurality of slide molds 45 can pass through the through holes 43b of the fixed mold 43. It slides inside and advances into the cavity 61 toward the movable mold 41. With the advancement of the slide mold 45, the cavity volume corresponding to the slide mold 45 does not fluctuate (enlarge).

  At this stage, the portion of the thermoplastic resin R in the cavity 61 between the movable mold side molding surface 41a and the fixed mold side molding surface 43a is brought into contact with the molding surfaces 41a and 43a at an early stage due to the influence of the mold temperature. Since it is cooled, it forms a surface layer as a hard skin layer 33 with no voids, while the inner part of the thermoplastic resin R is hardly affected by mold temperature and is in a highly viscous gel state. Therefore, the expansion of the cavity volume causes the thermoplastic resin R that has been compressed by the movable mold 41 and the stationary mold 43 to be expanded by being pulled by the movable mold side molding surface 41a. At this time, the thermoplastic resin R is also released from the compression, and the fibers in the resin R are elastically restored, and expansion of the thermoplastic resin R is promoted by this elastic restoring force (spring back phenomenon). As a result, the hard skin layer 33 with few voids is formed on the surface, and the door module panel 9 in which the expansion layer 35 having a large number of voids is formed is formed.

  On the other hand, the thermoplastic resin R in the cavity 61 corresponding to the mounting portion 19 and the fastening portion 25 is not moved in the cavity 61 by the slide mold 45 following the retraction operation even when the movable die 41 is retreated in the cavity volume expansion direction. Therefore, the cavity space is not enlarged, and the attachment portion 19 and the fastening portion 25 made of the solid solid layer 37 are formed.

  Finally, the movable mold 41 is retracted and the mold 47 is opened, so that the molded product, that is, the door module panel 9 is removed.

(Effect of embodiment)
A skin layer 33 is formed on the entire panel body 15 of the door module panel 9, and an expanded layer 35 having a large number of voids inside and having a lower resin density than the skin layer 33 is formed. . For this reason, compared with the case where the panel main body 15 is the same thickness, and the surface and the inside are both formed with the same resin density as the skin layer 33, the weight reduction of the door module panel 9 can be achieved.

  Moreover, the attachment part 19 which is an attachment location to the door inner panel 7 of the door module panel 9, and the fastening part 25 for attaching the front and rear guide rails for raising and lowering the wind glass in the door module panel 9 Since the compressive stress is higher than that of the panel body 15, and the attachment portion 19 and the fastening portion 25 are formed of a solid solid layer 37 that does not have the expansion layer 35, the attachment portion 19 and the fastening portion. The strength against the compressive strength and shearing force of 25 can be increased.

  Further, even when the mounting accuracy of the plurality of hydraulic cylinders 51 is different by using a plurality of hydraulic cylinders 51 with stable pressing force and a plurality of inexpensive coil springs 53 and urging the movable plate 49 with these, Since the plurality of coil springs 53 are arranged in combination with these, the portion where the urging force of the hydraulic cylinder 51 is insufficient can be compensated by the coil spring 53, and the movable plate 49 is evenly urged without being distorted. The plurality of slide dies 45 can be pressed with a uniform pressing force. For example, among the four hydraulic cylinders 51 shown in FIG. 5, when the urging force of the hydraulic cylinder 51 shown at the center on the right side is smaller than the urging force of the other hydraulic cylinders 51, it is arranged at least around the periphery. Since the three coil springs 53 are supported by the first fixed body 55 and bias the movable plate 49, the movable plate 49 is evenly biased without distortion.

  This ensures that the door module panel 9 of stable quality formed by the solid layer 37 having a uniform shape and a solid shape is reliably formed as the thickness of the mounting portion 19 and the fastening portion 25 formed by the slide mold 45 is set. be able to.

  Further, the movable plate 49 is not urged only by the expensive hydraulic cylinder 51 but is urged by using the hydraulic cylinder 51 and the inexpensive coil spring 53 together. The molding apparatus 31 can be made inexpensive as compared with the case where the biasing is performed only with this.

  Further, the hydraulic cylinder 51 and the coil spring 53 are supported by separate fixed bodies 55 and 57, and the first fixed disposed at a position closer to the movable plate 49 than the second fixed body 57 that supports the hydraulic cylinder 51. By supporting the coil spring 53 with the body 55, the coil spring 53 can have a short free length. That is, since the hydraulic cylinder 51 is generally a longer device than the coil spring 53, when the hydraulic cylinder 51 and the coil spring 53 are supported by the same fixed body, the coil spring 53 is the same length as the hydraulic cylinder 51. The movable plate 49 cannot be pressed stably. However, the coil spring 53 can be shortened by supporting the coil spring 53 to the first fixed body 55 that is closer to the movable plate 49 than the second fixed body 57 that supports the hydraulic cylinder 51. Since the movable plate 49 can be pressed stably and the material cost can be reduced, the molding apparatus 31 can be made more accurate and inexpensive.

(Other embodiments)
In addition, the above-mentioned embodiment is an illustration of this invention, Comprising: This invention is not limited to this example. For example, the following configuration may be used.

  That is, in the above embodiment, the slide mold 45 is provided on the fixed mold 43, but may be provided on the movable mold 41. In other words, the slide mold may be provided on one of the fixed mold 43 and the movable mold 41 and presses the other of the fixed mold 43 and the movable mold 41 when the movable mold 41 is retracted.

  Further, in the above embodiment, the movable plate 49 is urged by supporting the base end side of the coil spring 53 on the first fixed body 55. However, instead of the coil spring 53, another elastic member such as a leaf spring or elastic rubber is used. Elastic polyurethane or the like may be used.

  In the above embodiment, the hydraulic cylinder 51 and the coil spring 53 are supported by the first and second fixing bodies 55 and 57, respectively. However, the hydraulic cylinder 51 and the coil spring 53 are not supported by separate fixing bodies. You may make it support by a fixed body. In this case, it is preferable to configure the fixed body so that the proximal end side of the coil spring 53 is closer to the movable plate 49 than the proximal end side of the hydraulic cylinder 51.

  In the above embodiment, four hydraulic cylinders 51 and sixteen coil springs 53 are arranged. However, this number is arbitrarily set by the molding apparatus, and is not limited to this embodiment. It is set arbitrarily.

  Moreover, in the said embodiment, although the fiber-containing thermoplastic resin R was used as resin inject | emitted to the cavity 61, it is also possible to put a foaming agent into this resin, or not to insert a fiber when a foaming agent is put. is there.

  Moreover, although the case where the door module panel 9 was shape | molded by the shaping | molding apparatus 31 was shown in the said embodiment, the foamed resin molded object shape | molded by this shaping | molding apparatus 31 is not restricted to this, The inner plate and trunk of the back door of a motor vehicle A board etc. may be shape | molded and it can apply also to molded objects other than a motor vehicle.

  As explained above, the present invention fills a foamed resin molded body by filling a cavity of a molding die having a fixed die and a movable die and expanding the cavity volume by retracting the movable die. This is useful for a molding apparatus for molding.

It is sectional drawing which shows the lower part of the side door of a motor vehicle. It is a top view which shows a door module panel. It is the III-III sectional view taken on the line of FIG. It is a figure which shows the state which retracted the movable mold | type in FIG. It is the top view which looked at the shaping | molding apparatus which concerns on embodiment of this invention from the 2nd stationary body side.

Explanation of symbols

31 Molding Device 41 Movable Die 43 Fixed Die 45 Slide Die 47 Mold Die 49 Movable Plate 51 Hydraulic Cylinder 53 Coil Spring (Elastic Member)
55 1st fixed body 57 2nd fixed body 61 Cavity R thermoplastic resin

Claims (2)

Forming a foamed resin molding by filling a thermoplastic resin into the cavity of a molding die having a fixed die and a movable die arranged opposite to the fixed die, and retracting the movable die to enlarge the cavity volume. A molding device for
A plurality of slides which are provided on one of the fixed mold and the movable mold and hold the volume of a part of the corresponding cavity constant by pressing the other of the fixed mold or the movable mold when the movable mold is retracted. Type,
A movable plate in which the plurality of slide molds are erected apart from each other;
A plurality of elastic members and a plurality of hydraulic cylinders supported by a fixed body to press the slide mold and biasing the movable plate in the pressing direction;
A molding apparatus comprising: The molding apparatus according to claim 1, wherein
The fixed body includes a first fixed body that supports the elastic member, and a second fixed body that supports the hydraulic cylinder,
The molding apparatus, wherein the first fixed body is disposed at a position closer to the movable plate than the second fixed body.

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