JPH0852757A - Injection molding machine and clamping device in the same - Google Patents

Abstract

PURPOSE:To provide a vertical injection molding machine which is easy of handling such as mold transfer and mold matching and of attachment/ detachment operation, eliminate troubles caused by sliding resistance between a platen and a tie bar and protect the mold from being damaged by reflecting directly the precision of the mold in that of the mold matching. CONSTITUTION:With a movable side plate and a tie-bar eliminated, a mold itself or a mold holder is fixed directly by clamps 8, 8 which are joined as a clamping device on both sides of the mold, a lower mold 2 is fixed by chucks 5, 5 on the cradle 1 on the fixed side, and injection is carried out with it placed on a parting surface PL.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical injection molding apparatus for molding plastic, rubber and the like and a mold clamping apparatus in the injection molding apparatus.

[0002]

2. Description of the Related Art Conventional vertical injection molding apparatuses of this type are roughly classified into three types. In the first type, as shown in FIG. 9, the movable side plate B is vertically movable with respect to the fixed side plate A while being guided by the tie bars C, C, and the fixed side plate A and The upper mold D and the lower mold E are attached to the movable side plate B by using tightening metal fittings, bolts, etc., and the movable side plate B is moved up and down by an actuator F to clamp and open the mold.

As shown in FIG. 10, the second type is an upper die which is laterally movable between the fixed side plate A and its outer side position at the lower part of the fixed side plate A in the first type. A holder G is provided, and an upper die D is engaged with and held by the upper die holder G so as to be vertically movable, and the upper die D is laterally moved to the outside of the die clamping region to release the molded product.

In the third type, as shown in FIG. 11, a lower die holder I is provided on the upper side of the lower side of a U-shaped frame H so as to be slidable in the lateral direction, and a lower die E is attached to the lower die holder I. An upper mold holder G is provided on the lower part of the upper side so as to be vertically movable by an actuator F, and after molding, the lower mold holder I is slid laterally to take out a molded product.

In addition, the molding apparatus having the structure shown in FIG.
In the horizontal injection molding apparatus in which the vertical injection molding apparatus shown in FIG. 9 is placed horizontally, in the process of moving the movable side plate B, the movable mold D is strongly advanced to a position approaching the fixed mold E. Contrary to this, after the two molds approach each other, the wedges J, J are used to perform the mold touch under a relatively low pressure under a low mold clamping force.

[0006]

The conventional vertical injection molding machine described above has the following disadvantages and disadvantages. a. In either model, the movable die is attached to the movable side plate (platen), and the movable side plate is generally large and heavy in order to secure its rigidity. Requires the heavy movable plate to be moved up and down, and because there is a gap between the bush and the tie bar in the movable plate, the sliding accuracy of the movable plate tends to be impaired. The molds are becoming more complicated year by year, and more precise is required.Since a mold processed with high precision is attached to such a movable side plate that does not have high precision, it is necessary to match the molds of both molds. There is a tendency for the molds to be damaged, because the molds tend to have a parallel relationship and the cores do not match.

B. In the first and second types, not only is the upper die or the fixed side plate disposed above the lower die and is not opened, but a tie bar is erected upright around the lower die, so that the lower die is attached to the lower die. Difficult to apply the insert member. c. In the first and third types, it is necessary to deliver the molded product and the sprue runner by the take-out machine, and it may be necessary to replace the attachment for each molded product.

D. In each of the first to third types, the pressing force required for the mold clamping is because the movable mold vertical moving means and the mold clamping means perform the vertical movement of the movable side plate (platen) by a common actuator. Even if the value is small, the heavy-duty powerful actuator for moving the movable plate is used to press and clamp the mold, and in addition to the above-mentioned movement of the movable plate, the sliding accuracy is insufficient. , Tends to damage the mold. e. In the first and second types, since there is a tie bar around the die, the tie bar hinders the die replacement work, and in any of the types, tightening metal fittings, bolts, Since the mold is attached using a holder or the like, not only is the transfer of the mold itself restricted, but also the workability of the mold replacement becomes extremely complicated.

F. In the molding apparatus having the structure shown in FIG. 12, the mold is clamped under a low mold clamping force after the two molds approach each other, but the mold clamping advances the movable side plate. The mold clamping force is actually required to be about several hundreds of kg due to the weight and friction of the movable parts. Therefore, when the mold matching does not match, or when there is clogging due to residual foreign matter in the mold matching part between the thin hole and the sharp pin, etc. Is inevitable due to inertial response delay.

Therefore, an object of the present invention is to provide a vertical injection molding apparatus which is easy and easy to handle such as mold transfer, mold matching, and the like, and which can be easily attached and detached. Another object is to provide a simple structure. In addition to eliminating the adverse effects of the sliding resistance between the platen and the tie bar, the accuracy of the mold itself is directly reflected in the mold matching accuracy, making it possible to easily achieve high-precision mold matching and prevent damage to the mold. It is to provide a vertical injection molding device and a mold clamping device in the injection molding device that can be prevented, and another object is to take out a molded product and insert the lower mold at the same time. Another object of the present invention is to provide a vertical injection molding device that facilitates insert work, and another object is to provide a vertical injection molding device in which the equipment around the mold is compact. Sprue It is to provide a vertical injection molding apparatus can be performed easily discharged runner.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention mounts and fixes a lower die as a fixed die on a pedestal, and above the pedestal, a movable die in a conventional device. The movable plate for mounting and the tie bar for guiding the movable plate are removed, and instead of this, a mold transfer device that can transfer vertically and laterally while holding the movable mold is provided, and the movable mold is fixed from above by the mold transfer device. In addition, the pedestal is provided with a movable mold clamping clamp, and the injection unit is arranged in a horizontal type with its axis aligned with the parting surface of the fixed type and the movable type. In addition, as a mold clamping device, a wedge type clamp that engages with both sides of a movable mold placed on a fixed mold is adopted, and a lower mold as a fixed mold is fixed to a cradle by a chuck. What you did It is an butterfly.

[0012]

Operation: The movable die is lowered from above the fixed die fixed to the cradle by the die transfer device and placed on the fixed die, and when the clamps are operated on both sides, the fixed die and the movable die are separated from each other. It is clamped accurately with precision. The injection unit presses its nozzle into a nozzle touch formed on the parting surface of the fixed mold and the movable mold after mold clamping, and the molten resin is injected and filled into the cavity through the injection hole to be molded.

The fixed mold is held and transferred by the mold transfer device and is easily fixed to the pedestal by the chuck, and the movable mold is gripped and transferred by the mold transfer device so that the vicinity of the mold is maintained. Since there is no need for a tie bar and an upper die mounting plate, lower die die exchanging work and insert work can be performed without disturbing them.

[0014]

Embodiments of the present invention will be described in detail below with reference to the drawings. As a vertical injection molding apparatus to which the present invention is applied, for example, as shown in FIGS. 1 and 2, a lower mold as a fixed mold 2 is mounted on a pedestal 1 and a movable mold is mounted on the fixed mold 2. The upper mold as 3 is provided so as to be able to move up and down, and the injection unit 4 adopts a model in which it is arranged so that its axis coincides with the parting surface PL.

As a special construction of the present invention with respect to the above type, as shown in detail in FIGS. 1 to 3, for example, the fixed mold 2 is removably attached to the pedestal 1 by chucks 5 and 5 from the front-rear direction. In addition, while the movable die 3 is held by the die transfer device 6 of the bidirectionally moving vertically and horizontally or the chuck 7 in the robot hand, the transfer device 6 moves the die up and down above the fixed die 2 to align and open the die. In addition, in the ascending position, the molded product is stored, the sprue runner is discharged, and the mold is moved laterally.

As the chucks 5 and 5, for example, a structure in which a claw operated by a fluid pressure actuator is brought into contact with and separated from the front and rear portions of the fixed die 2, and as the die transfer device 6, for example, a fluid pressure actuator is used. The chuck 7 can be provided so as to be slidable in the lateral direction while being guided by the guide rod, and the guide rod itself can be moved up and down so as to be vertically movable.

On the right and left sides of the fixed die 2 mounting portion on the pedestal 1, the wedge type clamps 8 for clamping the fixed die 2 and the movable die 3 are guided in the left and right direction while being guided by the guides. It is provided so that it can move forward and backward. The wedge-shaped clamps 8 and 8 are provided with trapezoidal grooves having an upward pressing surface 9 and an obliquely downward pressing surface 10 toward the tips thereof, and the downward pressure receiving surfaces 11 and 11 corresponding to the pressing surfaces 9 are provided on both sides of the fixed die 2 against this. And a fixed die 2 and a movable die 3 are aligned with each other, by forming a receiving portion having a diagonally upward pressure receiving surface 12, 12 corresponding to the pressing surface 10 on both sides of the movable die 3. In this state, the wedge-shaped clamps 8 and 8 are advanced from both sides to allow the receiving portions of the fixed and movable molds 2 and 3 to be received in the trapezoidal grooves of the wedge-shaped clamps 8 and 8 while the oblique downward pressing surfaces 10 and 10 are used. Both the fixed and movable dies 2 and 3 are clamped by the pressing force via the upward pressure receiving surfaces 12 and 12.

As the equipment for advancing and retracting the wedge-shaped clamps 8, 8, for example, as shown in detail in FIG.
Is provided with a fluid pressure actuator 13 so that the cylinder itself can be moved in the axial direction, and the levers 14 and 14 are connected to both ends of the fluid pressure actuator 13 by a pin 16 in an elongated hole 15 at the base. The pin 14 is connected to the wedge-shaped clamp 8 by a pin 19 in a long hole 18 at the end while being pivotally attached to the pedestal 1 by a shaft 17, so that at the time of operations such as mold opening, mold matching, and mold replacement. , By contracting the fluid pressure actuator 13,
Both wedge type clamps 8 and 8 are fixed via the
Is kept away from the lever 1, and the fluid pressure actuator 13 is extended in the opposite direction, so that the lever 1
Both wedge-shaped clamps 8 and 8 are advanced through 4, 14 and their trapezoidal grooves are pressed against the receiving portions of the fixed die 2 and the movable die 3, and the fixed die 2 and the movable die 3 are parted by the wedge action. The surfaces PL are pressed against each other so that they can be clamped.

The equipment for advancing and retracting the wedge-shaped clamps 8, 8 is not limited to the above structure, but the lever 1
Alternatively, the electric screw feeders may be used to swivel the screws 4 and 14, and the wedge-shaped clamps 8 may be directly advanced and retracted by the electric screw feeders.

In addition to the above, as equipment for changing the mold,
As shown in FIG. 2, a mold standby unit 20 and a mold discharge unit 21 are separately provided on both the left and right sides of the injection unit 4, and the mold is replaced at an intermediate position between the mold standby unit 20 and the mold discharge unit 21. It is desirable to dispose the robot 22 for use in the die so that the die can be exchanged in accordance with the forming program, and the robot 23 for the insert may be placed instead of or in the vicinity of the robot 22 for exchanging the die. . The mold transfer device 6 may be omitted and the mold replacement robot 22 may be used also as the mold transfer device 6.

The molding operation will be described based on the above configuration.
First, while the fluid pressure actuator 13 is contracted to keep both the wedge type clamps 8 and 8 separated from the fixed die 2 and the movable die 3, the fixed die 2 is placed on the pedestal 1 by the die exchange robot 22. Then, the chucks 5 and 5 are fixed in place. Next, after the movable die 3 is aligned with the fixed die 2 by the die transfer device 6 with position regulation, the fluid pressure actuator 13 is extended to move both wedge die clamps 8 and 8 to the center, The fixed die 2 and the movable die 3 are clamped.

After the completion of the mold clamping, the injection unit 4 is advanced, and the cavity is injection-filled with the molten resin through the nozzle touch and the injection hole formed corresponding to the parting PL surface of the fixed mold and the movable mold. After timely waiting for cooling, the injection unit 4 is retracted, and the fluid pressure actuator 13 is contracted to fix both wedge-shaped clamps 8 and 8 away from both movable molds 2 and 3, and the movable mold 3 is moved by the mold transfer device 6. Is moved upward and laterally to store the molded product and discharge the sprue runner, and thereafter, the movable mold 3 is placed on the fixed mold 2 by the mold transfer device 6 and the mold is clamped for the next molding. Then, such an operation is automatically repeated.

Regarding the receiving portions of the fixed mold 2 and the movable mold 3 which are provided corresponding to the trapezoidal grooves formed near the tip of the wedge clamp 8, the fixed mold 2 and the movable mold 3 themselves are the same as in the above embodiment. However, when the fixed mold 2 and the movable mold 3 of the type held in separate holders are adopted, the holder may be formed with a pressure receiving surface.

As for the pressure receiving surface of the receiving portion, as shown in FIG. 4, the upward pressure receiving surfaces 12, 12 of the movable die 3 are formed horizontally and the downward pressure receiving surfaces 11, 11 of the fixed die 2 are formed obliquely. In addition, the wedge-shaped clamps 8 and 8 corresponding thereto may be provided with a trapezoidal groove having an obliquely upward pressing surface 9 and a downward pressing surface 10, or as shown in FIG. Both the surfaces 11 and 11 and the upward pressure receiving surfaces 12 and 12 of the movable die 3 are formed obliquely, and the wedge-shaped clamps 8 and 8 corresponding thereto have an oblique upward pressing surface 9 and an oblique downward pressing surface 10. A trapezoidal groove may be provided, or the upward pressure receiving surfaces 12, 12 of the movable mold 3 are formed obliquely as shown in FIG. Pair with wedge-shaped clamp 8 It may be loosely fit.

As for the mold clamping device for the fixed mold 2 and the movable mold 3, clamps having other structures can be adopted instead of the wedge clamps 8. For example, as shown in FIG. 1 is provided with a fluid pressure actuator 13 so that its cylinder itself can be moved in the axial direction, and levers 2 are provided at both ends of the fluid pressure actuator 13.
4 and 24 are connected by a pin 16 in a long hole 15 in the base, and the levers 24 and 24 are pivotally attached to the pedestal 1 by a shaft 25 while the pressing claws 26 at the ends are the upward pressure receiving surfaces of the movable die 3. 12, the fluid pressure actuator 13 is contracted so that the pressing claws 26 of the levers 24 and 24 are separated from the movable mold 3 during the work such as mold opening, mold matching, and mold replacement. In this state, the fluid pressure actuator 13 is extended to prevent the lever 24,
The tip of 24 is brought into pressure contact with the upward pressure receiving surface 12 of the movable mold 3,
By the pressing action, the fixed mold 2 and the movable mold 3 may be pressed against each other on the parting surface PL so that the mold can be clamped.

Further, as shown in FIG. 8, for example, the fluid pressure actuators 27, 27 are fixed to the pedestal 1 at their bases, and the end of each fluid pressure actuator 27 has a pressing claw 26 at its tip. In addition to connecting the levers 28 with a pin 29 at the base, a guide piece 30 is fixedly provided on the back side of the lever 28 so that the lever 28 can be tilted as the lever 28 moves up and down. During work such as mold matching and mold replacement, the fluid pressure actuator 27 is extended to raise the levers 28, 28 as shown by the chain line in the drawing, and at the same time tilt the levers 28, 28 outwardly to push the pressing claw 26 at the tip. , 26 are kept away from the movable mold 3, and the fluid pressure actuators 27, 27 are contracted in the opposite direction, so that the lever 28,
While lowering 28, the pressing piece 26 at the tip thereof is pressed against the upward pressure receiving surface 12 of the movable die 3 under the standing state by the guide piece 30, and by the pressing action, the fixed die 2 and the movable die 3 are parted. The PLs may be pressed against each other so that the molds can be clamped.

On the parting surface PL of the lower mold 2 and the upper mold 3, a position regulating pin having a taper toward the tip is projected on one side and a position regulating hole corresponding to the position regulating pin on the other side. It is desirable to provide the position regulating mechanisms 31, 31 having the holes.

It is desirable to adopt a wedge type clamp as the mold clamping device in order to exert a strong clamping action,
In short, the upper part of the mold needs to be open except when the mold is clamped because of the transfer of the movable mold (upper mold), the mold replacement, and the insert work.

[0029]

As described above, according to the present invention,
It has the following effects. a. Since the movable die is moved by holding the movable die in the vertical direction and the lateral direction while holding it, the platen and the tie bar in the conventional device are omitted. When the mold is transferred from the mold clamping area to another place, there is no obstacle such as a platen and a tie bar near the upper part of the lower mold, and therefore replacement and insert work of the lower mold are extremely easy. b. The upper mold is gripped and transferred without moving up and down by a platen or the like in the conventional apparatus, and the fixed mold and the movable mold are clamped directly on both sides of the mold by clamps. Therefore, it is not necessary to consider the platen and the tie bar for mold clamping in the conventional apparatus, and therefore it is not necessary to consider the parallelism at the time of mold clamping due to the wear that is likely to occur in the tie bar part and the distortion of the platen itself. Can show the precision of the mold as it is. c. Since the movable die is transferred by providing the die transfer device for directly holding the movable die, it is not necessary to simultaneously move up and down the equipment for clamping other than the movable die unlike the conventional device. , The weight to be raised and lowered is remarkably light, and therefore, when the fixed mold and the movable mold are matched with each other, the response is quick because the influence of inertia is small, and when there is clogging due to residual foreign matter in the mold, Abnormalities can be easily detected and stopped, and mold damage due to clogging can be reliably prevented.

D. Since the platen and tie bar in the conventional device are omitted and the movable die can be laterally moved by the die transfer device to separate the molded product, the upper part near the lower mold can be removed when the molded product is separated. Since there is no obstacle because it is opened, the removal of the molded product and the insert work can be performed at the same time, and the molding cycle can be shortened. e. By adopting wedge-shaped clamps that act on both sides of the mold as the mold clamping device, not only a strong clamping function can be exhibited by the wedge action, but also pressing force to the mold acts uniformly.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view illustrating an injection molding device in a mold clamped state of the present invention.

FIG. 2 is a plan view of the injection molding apparatus of FIG. 1, partially omitted.

FIG. 3 is a side view of only a main part of the injection molding apparatus of FIG.

FIG. 4 is a partially cutaway front view showing only a main part of another embodiment of the wedge-shaped clamp.

FIG. 5 is a front view of only a main part showing still another embodiment of the wedge clamp.

FIG. 6 is a front view of only a main part showing still another embodiment of the wedge clamp.

FIG. 7 is a front view showing another embodiment of the clamp.

FIG. 8 is a front view showing still another embodiment of the clamp.

FIG. 9 is a front view illustrating a conventional injection molding device.

FIG. 10 is a front view illustrating another conventional injection molding apparatus.

FIG. 11 is a front view illustrating another conventional injection molding apparatus.

FIG. 12 is a side view illustrating still another conventional injection molding apparatus.

[Explanation of symbols]

 1 Cradle 2 Fixed type 3 Movable type 4 Injection unit 5 Chuck 6 Type transfer device 8 Clamp 9 Pressing surface 10 Pressing surface 11 Pressure receiving surface 12 Pressure receiving surface PL Parting surface

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Claims (4)

[Claims] 1. A lower die as a fixed die (2) is mounted and fixed on the pedestal (1), and is vertically contacted with and separated from the pedestal (1) above the pedestal (1). The mold transfer device (6) is provided, which is capable of transferring in the vertical direction and the lateral direction while holding the movable mold (3) without providing the movable plate for mounting the movable mold and the tie bar for guiding the movable plate. ) So that the movable die (3) is brought into contact with and separated from the fixed die (2) from above, and the clamps (8), (8) for clamping the movable die (3) are specially mounted on the pedestal (1). The injection unit (4) is further provided, and the injection unit (4) is arranged in a horizontal mold whose axis coincides with the parting surface (PL) of the fixed mold (2) and the movable mold (3). . 2. A fixed mold (2) as a mold clamping clamp.
The injection molding apparatus according to claim 1, wherein wedge-shaped clamps (8), (8) which engage with both sides of the movable die (3) mounted on the substrate are adopted. 3. The injection molding apparatus according to claim 1, wherein a lower mold as a fixed mold (3) is fixed to the pedestal (1) by chucks (5), (5). 4. A mold configured such that a lower mold as a fixed mold (2) is attached and fixed to a cradle (1), and a movable mold (3) is fitted from above the fixed mold (2). And a receiving portion having a downward pressure receiving surface (11) on both sides of the fixed die (2) and an upward pressure receiving surface (12) on both sides of the movable die (3). And a wedge-shaped clamp (2) provided with trapezoidal grooves on both sides of the fixed die (2) having pressing surfaces (9), (10) corresponding to the pressure receiving surface (11) and the pressure receiving surface (12). 8) and (8) are provided so that they can move back and forth, the wedge-shaped clamp (8) is advanced with its trapezoidal groove sandwiched between the receiving parts of the fixed mold (2) and the movable mold (3). A mold clamping device in an injection molding device characterized by the above.