JPH06304957A - Injection molding machine - Google Patents

Abstract

PURPOSE: To perform injection molding in a vacuum state, and to easily perform mold replacing work. CONSTITUTION: An internal vacuum box 16 is fixed under a clamp plate 15 and an upper heating plate 17 and an upper mold 18 are successively arranged in the internal vacuum box 16 and an external vacuum box 19 raised and lowered along a tie bar 20 is arranged outside the internal vacuum box to perform injection molding in a vacuum state. A movable plate 31 is arranged to the tie bar fixed to the clamp plate in a liftable manner and a guide rail 32 is arranged on one side of the movable plate so as to draw out a lower mold along the guide rail in such a state that the lower mold and the upper mold are separated mutually.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding machine for molding a synthetic resin material into a predetermined shape. More specifically, it enables injection molding to be performed in a vacuum state and facilitates die replacement work. The present invention relates to an injection molding machine.

[0002]

2. Description of the Related Art In a conventional injection molding machine, as shown in FIGS. 1 and 2, an upper mold 3 and a lower mold 4 are fixed to installation plates 1 and 2 by supporting frames 5 and 6, respectively. The lower die 4 and the supporting frames 5 and 6 are sealed with a packing 7 so that the lower die 4
A plurality of eject pins 8 for taking out the molded product are attached to each eject plate 9 by a spring 10.
Elastically, and each eject plate 9 is connected by another connecting piece 11 so that each eject plate 9 moves up and down together. Further, inside the lower mold 4, an intake hole 13 for maintaining a vacuum state in the cavity 12 in a state where the upper mold 3 and the lower mold 4 are connected to each other is formed, and an outer periphery of an upper surface of the lower mold 4 is formed. Fix other packing 14 for blocking the outside air during the intake work. Therefore, when the compressor (not shown) operates while the lower mold 4 is raised and connected to the upper mold 3, the air in the cavity 12 is sucked into the intake hole 1
Since it is discharged to the outside through 3, the inside of the cavity 12 can be maintained in a vacuum state. At this time, the packing 14 fixed to the outer periphery of the lower mold 4 serves to block the upper mold 3 and the lower mold 4 from the outside of the mold. In this manner, the molten synthetic resin is supplied and the injection operation is performed while the suction work is performed, that is, the inside of the cavity 12 is maintained in the vacuum state. After the injection work is completed by the above-described operation, the mold is separated, and the connecting piece 11 is lifted by the elevating means.
Is raised, the eject plate 9 fixed to the connecting piece is also raised, whereby the eject pin 8 rises while compressing the spring 10 to push the molded product out of the mold.

[0003]

However, such a conventional injection molding machine has the following problems. First of all, since the packing 14 for sealing the inside of the cavity 12 is fixed to the upper surface of the lower mold 4, the packing 14 is damaged by the upper mold 3 by the repeated work and the sealing effect is lowered, so that the vacuum efficiency is improved. Lower, which results in packing 1
I had to change 4 often. Second, the lower mold 4 is provided with an intake hole 13 for sucking the air in the cavity 12.
It is difficult to process the intake hole because it is directly formed on the base plate, and the vacuum work cannot be performed because the intake hole 13 is often blocked during injection molding. Thirdly, changing the packing of the mold was troublesome, and the packing was consumed so much that there were many problems in continuous work. Fourth, when a heavy weight mold is settled on the installation plate for changing the mold, the packing operation makes the settling work difficult, and vacuum breaking is very difficult. Fifth,
There were many design difficulties for maintaining a vacuum state for each mold.

Therefore, the present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to house a mold in a vacuum box installed so as to move up and down along the internal vacuum box. By making an injection molding machine like this, and performing the injection molding work while maintaining a complete vacuum state in the vacuum box, the defective rate due to air bubbles is reduced and the vacuum box is kept in the vacuum box during the mold replacement work. The fixed upper mold is pulled out downward so that it can be attached and detached.

[0005]

In order to achieve the above object, the injection molding machine of the present invention has an internal vacuum box fixed to the lower part of a clamp plate and an upper heating plate inside the internal vacuum box. The upper molds are sequentially installed, an external vacuum box that moves up and down along a tie bar is installed outside the internal vacuum box, and a movable plate is installed on the tie bar fixed to the clamp plate so that the movable plate can move up and down. By installing a guide rail on one side of the plate, the lower die is pulled out along the guide rail in a state where the lower die is separated from the upper die.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A detailed description will be given below with reference to FIGS. 3 to 12 of the accompanying drawings showing an embodiment of the present invention.

3 to 6 are right side views showing the operating state of the injection molding machine of the present invention. In the injection molding machine of the present invention, the internal vacuum box 16 is fixed to the lower portion of the clamp plate 15, and the upper heating plate 17 is provided inside the internal vacuum box.
The upper mold 18 is sequentially fixed, and an outer vacuum box 19 is installed outside the inner vacuum box so as to move up and down along a tie bar 20. The external vacuum box 19 is connected to the tie bar 20 fixed to the clamp plate 15, and the rod of the cylinder 22 is fixed to the bracket 21 fixed to the outer surface of the external vacuum box 19. The outer vacuum box 19 will move up and down along the tie bar 20.
A plurality of lifting grooves 23 are formed on the clamp plate 15,
Upper heating plate 1 fixed inside the internal vacuum box 16
A plurality of support rods 24 are fixed to the head 7, and the heads 24a of the respective support rods 24 are located in the elevating groove 23 (see FIG. 8). Since the bolts 25 are fixed to the upper heating plate 17 at the positions between the support rods 24, the nuts 26 are fixed to the bolts 25 exposed above the clamp plate 15 with the upper heating plate 17 arranged on the clamp side. The upper heating plate 17 is attached to the clamp plate 15 by fastening (see FIG. 11). Here, the upper mold 18 is fixed to the upper heating plate 17. A heater (not shown) for heating the upper mold 18 is installed in the upper heating plate 17.

[0008] FIG. 7 of the accompanying drawings is a plan view of the clamp plate 15, and one of the support rods 24 positioned in the elevating groove 23 of the clamp plate 15 and serving to support the upper heating plate 17. An intake hole 27 is formed in the support rod and the upper heating plate 17 so as to communicate with the inside of the internal vacuum box 16 (see also FIG. 8), and hot oil is supplied to and discharged from the other two support rods. Oil holes 28a, 28b are formed, and an electric wire supply hole 29 for supplying power to the heater of the upper heating plate 17 is formed in the remaining one support rod. Then, the guide rail 3 is attached to one side of the movable plate 31 which is coupled to the tie bar 20 and moves up and down by the cylinder 30.
Since the lower die 33 and the lower heating plate 34 are installed on the guide rail 32, the lower heating plate 34 is moved along the guide rail 32 by the cylinder 35 fixed to one side of the movable plate 31. It will reciprocate. Also,
A take-out plate 41 for taking out a molded product is connected to the guide rail 32 by an elevating plate 36 and an iron rod 37, and a guide rail 32 and a fixing plate 38 are provided in an insertion hole (not shown) of the elevating plate 36. Other horizontal bar 3 fixed between
Since 9 is inserted, the product in the lower mold 33 is taken out while rising according to the operation of the cylinder 40.

[0009]

The operation of the injection molding machine of the present invention thus constructed will be described below. First, as shown in FIG. 3, the movable plate 31 is located at the bottom dead center, and the lower heating plate 3
4 will be described from the state in which the cylinder 35 is pulled out along the guide rail 32. Thus, the lower heating plate 3
After the mold 4 is pulled out along the guide rail 32, a mold release agent such as silicone oil is applied to the lower mold 33 so that the molded products can be easily separated, and a switch provided in a control box (not shown). Then, the lower die 33 fixed to the lower heating plate 34 is moved along the guide rail 32 by the cylinder 35 and placed on the movable plate 31, and the state shown in FIG. 4 is obtained. After that, when the movable plate 31 is lifted by the cylinder 30 fixed to the clamp plate 15 and the upper mold 18 and the lower mold 33 are stopped at positions close to each other, as shown in FIG. Since the hydraulic pressure acts, the external vacuum box 19 connected to the rod of the cylinder 22 and the bracket 21 descends along the tie bar 20 and is connected to the lower heating plate 34 to be in the state shown in FIG. On this occasion,
Since the packing 43a is fixed to the upper portion of the inner side surface of the outer vacuum box 19 that contacts the inner vacuum box 16, and the packing 43 is fixed to the lower end surface of the outer vacuum box 19, the inside is shielded from the outside air. In this state, vacuum pump (not shown)
When is activated, the air in the vacuum boxes 16 and 19 is discharged to the outside through the support rods 24 and the intake holes 27 formed in the lower heating plate 17, so that the inside of the vacuum boxes momentarily becomes a vacuum state. When the inside of the vacuum box becomes a vacuum state in this way, the cylinder 30 operates again to further raise the movable plate 31, so that the external vacuum box 19
Rises along the tie bar 20 while being connected to the lower heating plate 34. As a result, the upper mold 18 and the lower mold 33 are connected, and injection molding is performed in a vacuum state.

When the injection molding is completed by the above-mentioned operation, contrary to the above-mentioned operation, the cylinders 22 and 30 are
The external vacuum box 19 is raised by the movable plate 3
1 descends to bottom dead center and stops. When the movable plate 31 reaches the bottom dead center, another sensor (not shown) senses this and activates another cylinder 35 fixed to the movable plate 31. The plate 34 is pulled out along the guide rail 32. When the lower heating plate 34 is completely withdrawn, the cylinder 40 fixed to the guide rail 32 is activated, and the take-up plate 41 is moved upward to raise the connecting piece fixed to the eject plate similarly to the conventional injection machine. The product is taken out from the lower mold 33. The molding operation as described above is repeatedly performed.

FIGS. 8 to 12 of the accompanying drawings are side views showing a mounting state of the mold, and in order to mount the upper mold 18 on the upper heating plate 17, the upper heating located inside the internal vacuum box 16 is performed. If the plate 17 is exposed below the internal vacuum box 16, the work of mounting the upper mold is facilitated. This allows
As shown in FIG. 7, when the nut 26 fixed to the upper heating plate 17 and fastened to the bolt 25 exposed above the clamp plate 15 is unfastened, the upper heating plate 17 descends and is fixed to the upper heating plate 17. The supported rod 24 is lowered along the up-and-down groove 23. At this time, the lower part of the lower heating plate 17 is prevented from falling because the head 24a of the support rod 24 is restrained from descending at the position where it contacts the lower end of the elevating groove 23. As shown in FIG. 8, with the upper heating plate 17 descending and the lower heating plate 34 pulled out along the guide rails 32, the upper mold 18 and the lower mold 33 to be mounted are attached to the lower heating plate. After mounting on the lower mold 34, the lower mold 33 is temporarily assembled on the lower heating plate 34.

When the lower die 33 is temporarily assembled and the lower heating plate 34 is placed on the movable plate 31 by operating the cylinder 35, the lower die 33 is placed on the lower die 33 and the lower die 33 is placed on the lower die 33. As shown in FIG. 9, transferred with 33,
It will be located on the vertical line of the upper heating plate 17. After that, when the cylinder 30 fixed to the clamp plate 15 is actuated to raise the movable plate 31, the upper mold 18 and the lower mold 33 placed on the movable plate 31 rise, and the upper mold acts as the upper heating plate 17. The movable plate 31 is stopped at the connection position, that is, in the state as shown in FIG. When the upper mold 18 is connected to the upper heating plate 17 as described above, the upper mold 18 is firmly fixed to the upper heating plate 17 with bolts, and the temporarily assembled lower mold 33 is used.
When the movable plate 31 is further lifted by firmly fixing the bolts to the lower heating plate 34, the bolts 25 fixed to the upper heating plate 17 are exposed above the clamp plate 15, so that the bolts 25 are fixed as shown in FIG. The upper heating plate 17 is fixed to the clamp plate 15 by fastening the nut 26 to the clamp plate 15. As a result, the upper mold 18 and the upper heating plate 17 are positioned inside the internal vacuum box 16, and the work of mounting the mold is completed. Thereafter, the cylinder 30 is operated to lower the movable plate 31 to the bottom dead center, and at the same time, the other cylinder 35 installed on the movable plate 31 is operated to move the lower heating plate 34 fixed to the lower die 33 to the guide rail 32. Since it is pulled out along with, the molding work can be performed in the initial state as shown in FIG.

[0013]

As described above, according to the injection molding machine of the present invention, the following various effects and advantages can be obtained. (1) Since the external vacuum box 19 installed so as to be able to move up and down along the tie bar 20 is configured to be connected to the surface of the lower heating plate 34 and maintain the inside of the vacuum box in a vacuum state for forming work. The packing 43a does not have to be damaged, and a good quality molded product can be obtained. (2) Since the vacuum state is created inside the vacuum box through the upper heating plate 17 and the suction holes 27 formed in the support rod 24, there is no concern that the suction holes 27 will be blocked during the injection molding operation. (3) Since the lower die 33 is configured to be pulled out along the guide rail 32, the work of applying a release agent such as silicone oil becomes easy. (4) Since the lower heating plate 17 is exposed below the internal vacuum box 16 by the support rod 24 and the bolt 25, the mold is changed by the operation of the movable plate 31, so that the mold is changed. Work becomes easy.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a mold of a conventional injection molding machine.

FIG. 2 is a plan view showing a lower mold of a mold of the conventional injection molding machine shown in FIG.

FIG. 3 is a side view showing an embodiment of the injection molding machine of the present invention, in a state where the lower mold is pulled out along the guide rails.

FIG. 4 is a side view of the injection molding machine shown in FIG. 3 of the present invention in a state where the lower mold is moved vertically below the upper mold.

5 is a side view of the injection molding machine shown in FIG. 3 of the present invention in a state where the movable plate is raised and the upper die and the lower die are positioned close to each other.

FIG. 6 is a side view of the injection molding machine shown in FIG. 3 of the present invention in a state where an external vacuum box is lowered to seal the outer peripheries of the upper die and the lower die.

FIG. 7 is a plan view of a clamp plate of the injection molding machine shown in FIG. 3 of the present invention.

FIG. 8 is a side view of the injection molding machine shown in FIG. 3 of the present invention in which a die to be mounted is placed on a lower heating plate pulled out along a guide rail.

FIG. 9 is a side view of the injection molding machine shown in FIG. 3 of the present invention in a state where the mold moves vertically below the upper heating plate.

10 is a side view of the injection molding machine shown in FIG. 3 of the present invention in a state where an upper die and a lower die are raised by a movable plate and are connected to an upper heating plate.

11 is a side view of the injection molding machine shown in FIG. 3 of the present invention in a state where an upper heating plate is raised by a movable plate and fixed to a clamp plate.

FIG. 12 is a side view of the injection molding machine shown in FIG. 3 of the present invention in a state where the movable plate is lowered after the upper die is fixed to the upper heating plate.

[Explanation of symbols]

 15 Clamp plate 16 Internal vacuum box 17 Upper heating plate 18 Upper mold 19 External vacuum box 20 Tie bar 23 Lifting groove 24 Support rod 24a Head 25 Bolt 26 Nut 27 Intake hole 31 Movable plate 32 Guide rail 33 Lower mold

Claims (3)

[Claims] 1. An internal vacuum box (16) is fixed to a lower portion of a clamp plate (15), an upper heating plate (17) and an upper die (18) are sequentially installed inside the internal vacuum box, and the internal vacuum box (16) is provided. An external vacuum box (19) that moves up and down along the tie bar (20) is installed outside the vacuum box, and a movable plate (31) that can move up and down is attached to the tie bar (20) fixed to the clamp plate (15). By installing the guide rail (32) on one side of the movable plate, the lower mold (3
An injection molding machine characterized in that the lower mold is pulled out along the guide rail in a state where 3) is separated from the upper mold (18). 2. An upper heating plate (17) in which a plurality of lift grooves (23) are formed in the clamp plate (15), and a support rod (24) having a head (24a) is inserted into the lift grooves. The upper mold (18) is fixed to the upper heating plate (17), the bolt (25) is fixed to the upper heating plate (17) so as to be exposed above the clamp plate (15), and the upper mold (18) is fixed to the upper heating plate (17). The upper heating plate (17) with the nut (26) to the clamp plate (1
5. The injection molding machine according to claim 1, which is fixed to 5). 3. An intake hole (27) is formed in any one of the support rods (24) and the upper heating plate (17) so as to communicate with the inside of the internal vacuum box (16). The injection molding machine according to claim 2, wherein