JP2000280274A - Injection molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a small-sized injection apparatus with short molding cycle by decreasing burden of installation by decreasing clamping for injection molding of an insert molded article and decreasing a driving means for injection. SOLUTION: A rotary type injection molding apparatus is disclosed. A bottom mold 14 carried on a rotating table 12 is fitted movably up and down and a top mold 26 arranged above the rotating table positioned on an injection stage is supported movably up and down and a nozzle for an injection unit is fixed and supported above the top mold. A clamping pin 60 which can be pushed up by an elevating/descending driving means below the rotating table and by one stroke motion for pushing up the clamping pin, the bottom mold is fitted to the top mold and successively, both molds are integrally pushed on the fixed nozzle to perform clamping.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding apparatus, and more particularly to an injection molding apparatus suitable for molding an insert molded article, for example, a small rotor with a built-in magnet.

[0002]

2. Description of the Related Art In general, a small watch rotor is obtained as an injection molded product. The steps of the injection method for this type of insert product are as follows. First, in a mold in which a plurality of cavities are formed by a lower mold and an upper mold, a magnet material is loaded into the lower mold cavity while the mold is being opened. Thereafter, after the upper and lower molds are clamped, the injection nozzle is usually mounted on the runner gate of the upper mold and resin is injected and injected. After a predetermined time, the mold is opened and the product is extruded and removed. Since the runner resin remains in one mold, the runner resin is removed from the mold and the next injection step is started. Therefore, a single injection operation requires a mold clamping operation and an operation of connecting the nozzle of the injection unit to a gate communicating with the cavity of the mold that has been matched.

[0003]

However, the conventional injection molding method requires a driving mechanism for clamping the mold and a driving mechanism for connecting the injection nozzle to the runner gate during injection. However, there has been a problem that the burden on the apparatus is increased and the size of the apparatus is unavoidable. Further, as described above, a series of steps such as loading of the insert component into the cavity, resin injection into the mold-clamped cavity, product removal and runner removal must be performed until the product is taken out. This cycle time is currently 10
１１11 seconds, and it takes less than 2 seconds to obtain one product. Therefore, it is desired to further reduce the time.

[0004] As an apparatus for speeding up the injection work, a rotary type injection molding machine is known (Japanese Patent Laid-Open No. 8-28).
No. 1696). This is one in which two or more lower dies correspond to one upper die. A plurality of lower dies are arranged around the rotary table, and the mold clamping injection on one lower die side. In accordance with the work, the injection product is taken out from the other lower mold side to shorten the cycle time. However, even with this method, a mold clamping operation and a nozzle setting operation for injection are necessary, and there is a limit in shortening the cycle time.

An object of the present invention is to provide a compact injection device which reduces the load on equipment by reducing the number of driving means for injecting an insert molded product and which has a short molding cycle time, focusing on the above-mentioned conventional problems. And

[0006]

In order to achieve the above object, an injection molding apparatus according to the present invention is a rotary injection molding apparatus, wherein a lower die mounted on a rotary table is vertically movably mounted, and An upper mold disposed above a rotary table located on the injection stage is vertically movable and a nozzle of an injection unit is fixedly supported above the upper mold, and an elevation drive is provided below the rotary table. A mold clamping pin that can be lifted up by means is disposed, and the lower mold is pressed together with the upper mold by a one-stroke operation of pushing up the mold clamping pin. It is characterized by doing so.

Further, as an injection molding apparatus according to another configuration, a plurality of lower dies in which a plurality of stages including an injection stage are movably mounted are movably mounted, and a pair of upper dies are mounted on the injection stage. The pair of upper dies is arranged and supported so as to be able to move up and down for mold clamping while alternately moving between a mold clamping position and a retracting position. A nozzle of an injection unit is provided above the upper mold at the injection position. Is fixedly supported, and a mold clamping pin that can be pushed up by a lifting drive means is arranged below the rotary table, and the lower mold is moved by one-stroke operation of pushing up the mold clamping pin so that the lower mold is aligned with the upper mold. Subsequently, both the molds are pressed integrally to the fixed nozzle to perform mold clamping, and after the mold is opened by pulling down the mold clamping pin, the mold is rotated by rotating the rotary table and switching the upper mold. Was possible injection consists of repeating the forming the mold clamping by one stroke operation of the same clamping pins and replace.

[0008] With the above structure, the mold clamping pin is moved toward the injection nozzle where the mold matching and the mold clamping are fixed and supported.
It can be performed by a stroke operation. Therefore, since it is very simple and does not require a different driving unit for connecting the gate of the injection nozzle, the structure of the injection unit can be simplified, and it is not necessary to consider the consistency of the different driving units. Control can be simplified. In addition, the mold clamping and the subsequent injection posture are prepared by one stroke operation of the mold clamping pin, which leads to a reduction in cycle time. Further, a pair of upper dies is provided so as to alternately switch between the injection position and the standby position, and the lower dies which have been circulated by the rotation of the rotary table are similarly rotated by the clamping pins.
The effect of shortening the cycle time can be further improved by adjusting the mold clamping injection posture after the mold switching by the stroke pushing-up operation.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of an injection molding apparatus according to the present invention will be described in detail with reference to the drawings.

1 to 3 are overall perspective views of an injection molding apparatus.
It shows a front view and a side view. As shown in these drawings, in the injection molding apparatus, a rotary table 12 is arranged at a substantially central position of a base 10, and lower rotary molds 14 are provided at four positions on a peripheral portion of the rotary table 12. 90
It is provided at an equal angular position. Details of the rotary table 12 equipped with the lower molding die 14 are shown in FIGS. 4 and 5, and a roller gear mounted on the base 10 using a motor 16 mounted on the lower portion of the base 10 as a driving source. Cam unit 1
8 and is supported so as to rotate intermittently by 90 degrees in one direction. Roller gear cam unit 18
Is mounted with an index 20 so that the stop position of the rotation can be accurately detected. Rotary table 1
As shown in FIG. 5, lower molds 14 arranged at four places around 2 are fixed to a mold base 24 that is guided and raised by an elevating guide 22 fixed to the rotary table 12. The base 24 is lifted from the rotary table 12 by an ascending operation, and is matched with a molding upper mold 26 described later.

As shown in FIG. 6, an injection stage for discharging the resin to the clamped upper and lower dies is provided around the outer periphery of the rotary table 12 in which the lower dies 14 are provided at four places. 28A (in the figure), a material removal stage 28B (in the figure) for removing the molded product from the mold, an insert member supply stage 28C (in the figure) for loading the lower mold 14 with a magnetic material as an insert member, and an insert. A magnet material detection stage 28D for detecting whether the member is raised from the lower mold 14 and whether or not the member is loaded into the cavity.
Four stages (in the figure) are set. The rotary table 12 is rotationally driven and controlled so that each of the mounted lower dies 14 rotates at intervals of 90 degrees and stops at the four stages. Accordingly, the lower dies 14 mounted on the four positions of the rotary table 12 are simultaneously positioned on the respective stages 28A to 28D and circulate through the respective stages 28A to 28D by rotation. Work, material supply work, and work for detecting the presence / absence / float of magnet material can be performed. By such a rotary method, the injection molding of the insert member can be efficiently performed.

The injection stage 28A is provided with a pair of upper dies 26A and 26B at positions above the lower die 14 corresponding to the lower die 14 moved to the injection stage 28A by the rotary table 12. The pair of upper dies 26A and 26B are supported so as to be reciprocally movable sideways so as to be able to alternately move between a mold clamping position and a retracted position, and are also supported so as to be able to move up and down for mold clamping. That is, as shown in FIG. 2 and FIGS. 7 and 8, a vertically movable plate 34 that can be moved up and down by an elevating cylinder 32 is provided for a frame 30 erected on the base 10. A slider 36 that can move reciprocally is mounted on the upper side of the slider 34. A pair of upper dies 26A and 26B are fixed to the front surface of the slider 36, and one of the upper dies 26A (26B) corresponds to a position where the lower die 14 moved to the injection stage 28A and can be clamped, The other upper mold 26B (26A) corresponds to the mold clamping standby position on the side. Thereby, the upper dies 26A, 26
B can be moved alternately between the mold clamping position and the retracted position by driving the slider 36. Runner chuck means 38 (38A, 38B) for removing the runner generated by the previous injection from the upper mold are provided at the standby positions set on both sides of the mold clamping position.

The specific configuration of the runner chuck means 38 is shown in FIGS. A vertically movable support plate 40 is arranged in parallel with the horizontal movement line of the upper mold 26 (26A, 26B) by the lifting cylinder 39, and is directed to the standby position of the upper mold 26 at both left and right ends of the support plate 40. Arm 42 (42A, 42B) is provided. Arm 42A,
A chuck 46 capable of holding a runner 44 protruding from the upper surface of the upper mold 26 that has reached the standby position is provided at a lower end of the tip of 42B, and a sensor 48 for detecting the presence or absence of the runner 44 is attached. ing. Such a runner chuck means 38A, 38B is provided with one upper mold 2 with respect to the lower mold 14 located on the injection stage 28A.
When the mold 6A (or 26B) is in the mold clamping operation, the runner 4 of the other upper mold 26B (or 26A)
4, the runner 44 is removed from the upper mold 26 by using the operation of lowering the lower mold 14 for the releasing operation. In the embodiment, the support plate 40 is simultaneously lifted when the lower mold 14 is lowered, and the runner 44 is forcibly pulled up. Below these runner chuck means, runner chutes 50 (50A, 50B) are arranged (see FIGS. 7 and 8), and the upper mold 26 from which the runner 44 has been removed moves to the injection position, so that there is no obstacle below. Sometimes chuck 46
And the runners are discarded by natural fall.

Here, the mold clamping mechanism for performing the injection operation is configured as follows. As shown in FIGS. 2 to 3 and 11, an AC servomotor 52 is disposed below the base 10, and a pair of left and right ball screws 56 is wound around the motor 52 by a conductive belt 54.
Are projected above the base 10. An elevating base 58 is arranged above the base 10 on the lower surface side of the rotary table 12, and the elevating base 58 is screwed to the ball screw 56. Therefore, the servo motor 5
By the operation of 2, the elevating base 58 can move up and down. A mold clamping pin 60 protrudes from an intermediate portion of the elevating base 58 which is sandwiched between the screwed portions with the ball screw 56, and the pin position is set so that this pin coincides with the injection center of the injection stage 28A. The mold clamping pin 60 pushes up the mold base 24 of the rotary table 12 so that the lower mold 14 is aligned with the upper mold 26 waiting at the mold clamping center position above, and then further raised. As a result, the mold comes into contact with the injection unit 62 disposed above the upper mold 26 and is clamped. Therefore, the lower drive source servo motor 52
By operating the mold clamping pin 60, as shown in FIG. 5, from the mold opening position ((1) in FIG. 5), the lower mold 14 undergoes a mold matching operation with the upper mold 26, and this A mold clamping operation ((2) in the figure) of integrally pressing the molds 14 and 26 against the injection unit 62 to obtain a mold clamping force is continuously performed by one stroke operation of the mold clamping pin 60.

In order to clamp the mold, the injection unit 62 is mounted on an injection unit fixing frame 64 that is overhanging just above the injection stage 28A. I am going to receive it. That is, the unit mounting base 66 is horizontally disposed on the fixed frame 64, and the unit mounting base 66 is suspended from the mounting base 66 so that the center of the nozzle of the injection unit 62 coincides with the center of the mold clamping. The nozzle head 68 of the unit 62 fixedly supported by the fixed frame 64 is at a fixed position, and when the upper and lower molds 14 and 26 that have been fitted together ascend integrally, a pushing force is exerted on the end face of the nozzle head 68. The bearing is supported, and a mold clamping force is generated here.

The operation of the injection molding apparatus configured as described above is as follows. By rotating the rotary table 12 intermittently by 90 degrees by the index 20, the lower mold 14 of the rotary table 12
While being simultaneously located on the plurality of stages 28A to 28D including 8A, the stages 28A to 28D are circulated and moved.
As shown in FIG. 12, the working mode after the lower mold 14 reaches the injection stage 28A is that the mold clamping pin 60 is at the lower position, one upper mold 26A is located at the mold clamping center, and the other is. The upper mold 26B is in a standby position on the right side in the figure (A in the figure). The standby position is located on the left and right of the mold clamping position, but at the left standby position in the figure, the runner chuck means 38A removes the runner 44 removed from the upper mold 26A. From this state, the mold clamping pin 60 is pushed up to start the mold clamping operation (FIG. B). The mold clamping pin 60 pushes up the lower mold 14 to align with the upper mold 26A (stroke S1 in FIG. 5), and continues to ascend further (stroke S2 in FIG. 6). The mold is clamped by pressing against the surface. This operation is realized by one stroke operation of the mold clamping pin 60. At this time, the upper mold 26A and the other upper mold 26B adjacent to the upper mold 26A are attached to a common slider 36, and the slider 36 is
4, the upper mold 26B at the standby position to enter the ascending mode.
Is attached to the runner chuck means 38B.
Is ready to hold. Then, the runner chuck means 38B clamps the runner 44 remaining on the right upper mold 26B due to the previous injection (FIG. 3C). During this time, injection is performed, and the cavity formed between the lower mold 14 and the upper mold 26A is filled with resin.

After the injection operation and the clamping of the runner 44 are performed, the mold clamping pin 60 is lowered, and the mold is opened (FIG. 12D). By this mold opening operation, the upper mold 26A is lowered to the initial height position, and separated from the injection nozzle, whereby the runner 44 is removed from the nozzle. At this time, the upper mold 26B at the standby position is simultaneously lowered, so that the runner 4
4 is removed from the standby mold 26B. By this operation, the upper mold 26B at the standby position is in a moldable state, and the upper mold 26A used for injection molding is provided with the runner 44B.
Remains, the entire pair of upper dies 26A and 26B move leftward by the action of the slider 36 (FIG. 12E),
The upper mold 26 is replaced. Then, the runner chucking means 3 descends, and the presence or absence of the runner 44 of the upper mold 26A which has moved to the standby position is detected by the sensor 48, and the chucking state is started (FIG. 12F).

Thereafter, the state becomes the same as the state shown in FIG. 12A. The rotary table 12 is rotated by 90 degrees to move the next lower die 14 to the injection stage 28A, and is held by the runner chuck means 38B. The runner 44 is released and discarded through the runner chute 50. Thereafter, the same mode is repeated with the lower mold 14 replaced and the upper mold 26B replaced. And
Each of the stages 28A to 28A-2
In 8D, injection, product removal, loading of a magnetic material as an insert member, presence / absence of the magnetic material and floating detection are performed.

FIG. 13 is a time chart of the above-mentioned operation, and the operation form of each element described above can be understood from the figure.

As described above, in the present embodiment, in the injection stage 28A, the mold matching and the subsequent mold clamping can be performed between the injection nozzle by the one-stroke operation of the mold clamping pin 60. No double driving means for injection is required. As a result, it is possible to omit a driving means for connecting and moving the nozzle on the side of the injection unit to the cavity gate, thereby minimizing the size of the equipment and shortening the time from mold clamping to injection as much as possible. . Further, in the embodiment, a pair of upper dies 26 is disposed with respect to the lower dies 14 sequentially moved by the rotary table 12, and when one is in a mold clamping operation for injection, the other is. From the upper mold 26 to the runner 44
, It is possible to perform the mold clamping to the lower mold 14 arriving one after another in a short cycle time. Therefore, each stage 2 in which a plurality of lower dies 14 mounted on the periphery of the turntable 12 are arranged around
8A to 28D, the runner 44 which needs to be removed before the injection is performed by using the mold clamping operation while simultaneously performing the operation required for molding. The injection device can be operated in a shorter cycle. In the case of the embodiment, it was possible to realize a manufacturing cycle for obtaining one product in one second while having a structure in which one cavity is formed by the upper and lower dies. As a result, the product manufacturing cycle time can be reduced by almost half as compared with the conventional rotary injection device.

[0021]

As described above, according to the present invention,
In a rotary injection molding apparatus, a lower mold mounted on a rotary table is vertically movably mounted, and an upper mold disposed above a rotary table located on an injection stage is vertically movably supported. A nozzle of the injection unit is fixedly supported above the mold, and a mold clamping pin that can be pushed up by a lifting drive means is arranged below the rotary table, and the lower mold is moved by one stroke operation of pushing up the mold clamping pin. Since the molds are clamped by pressing both molds integrally to the fixed nozzle following the mold matching of the upper mold, the equipment load is reduced by reducing the driving means for injecting the insert molded product, and the molding is reduced. A small injection device with a short cycle time can be obtained.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of an injection molding apparatus according to an embodiment.

FIG. 2 is a front view of the injection molding apparatus according to the embodiment.

FIG. 3 is a side view of the injection molding apparatus according to the embodiment.

FIG. 4 is a plan view and a side view of a rotary table part.

FIG. 5 is a sectional view showing a mold opening state and a mold clamping state of a mold.

FIG. 6 is an explanatory schematic diagram of a stage around a rotary table.

FIG. 7 is a side view of the apparatus showing an elevating mechanism of the upper mold.

FIG. 8 is a front view of FIG. 7;

FIG. 9 is a plan view and a front view of the runner chuck means.

FIG. 10 is a side view of the runner chuck means.

FIG. 11 is a plan view of a driving portion of a mold clamping pin.

FIG. 12 is an explanatory diagram of a mold operation in an injection stage.

FIG. 13 is a time chart showing the operation of each element in the injection stage.

[Explanation of symbols]

 Reference Signs List 10 base 12 rotary table 14 lower mold for molding 16 motor 18 roller gear cam unit 20 index 22 elevating guide 24 mold base 26 upper mold for molding 28A injection stage 28B material removal stage 28C insert member supply stage 28D magnet material detection Stage 30 Frame 32 Lifting cylinder 34 Vertically movable plate 36 Slider 38 Runner chuck means 39 Lifting cylinder 40 Support plate 42 Arm 44 Runner 46 Chuck 48 Runner sensor 50 Runner chute 52 AC servomotor 54 Wound conduction belt 56 Ball screw 58 Lifting base 60 type Tightening pin 62 Injection unit 64 Injection unit fixing frame 66 Mounting base 68 Nozzle head

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Eiichi Hanzawa 74-17 Uchida Gen, Shimo-Shimizu, Tsuruoka-shi, Yamagata F-term in Techman Industrial Co., Ltd. 4F202 CA11 CB01 CC01 CL02 CL11 4F206 JA07 JC02 JC08 JL02 JM02 JN32 JQ83

Claims (2)

[Claims] In a rotary injection molding apparatus, a lower mold mounted on a rotary table is vertically movably mounted,
An upper mold disposed above the rotary table located on the injection stage is vertically supported, and a nozzle of the injection unit is fixedly supported above the upper die. A mold clamping pin that can be pushed up by a driving means is disposed, and the lower mold is pressed together with the upper mold by a one-stroke operation of pushing up the mold clamping pin. An injection molding apparatus characterized in that: 2. A plurality of lower dies on which a plurality of stages including an injection stage are mounted so as to be circulatingly movable are vertically movable, and a pair of upper dies are provided on the injection stage. The rotary table is configured to support a vertically movable position for mold clamping while allowing the clamped position and the retracted position to be alternately movable, and a nozzle of an injection unit to be fixedly supported above the upper mold at the injection position. A mold clamping pin which can be pushed up by a lifting drive means is disposed below the lower nozzle, and the lower mold is integrated with the upper mold by one stroke operation of pushing up the mold clamping pin. The mold is closed by pressing down on the mold, and after the mold is opened by pulling down the mold clamping pin, the mold is exchanged by rotating the rotary table and switching the upper mold, and one stroke of the same mold clamping pin is performed. An injection molding apparatus characterized in that injection can be repeatedly performed by closing a mold by an operation.