JPH04208422A - Rotary infection molder - Google Patents

Abstract

PURPOSE:To secure the retention of mold closing by a method wherein the mold clamping force applied to a mold after injection molding is properly hed by the elastic force of spring members, which are installed between a mold clamping plate and a mold mounting plate, until a shutter plate, which receives the reactions of the spring members by restricting a pressure receiving rod, is removed from the tip end of the pressure receiving rod. CONSTITUTION:Every mold clamping unit 31 is rotated by 90 deg. together with a rotary table 28. At each mold clamping position, molds 51 are clamped together by pressing a mold clamping plate 35 through a mold opening and closing rod 39 with the ram 23a of a mold clamping cylinder 23. When an injection cylinder 52 is retreated so as to part from the mold 51 after the completion of injection, the ram 23a is raised to its initial position for rotation, resulting in removing the pressing force of the ram 23a. However, the mold clamping force of the mold 51 is properly retained by means of the elastic force of the spring members 36. Said elastic force is maintained until the mold clamping unit 31 reaches a mold opening and closing position and relieved when a shutter plate 41, which receives the reactions of the spring members 36 by restricting a pressure receiving rod 40, is removed from the tip end of the pressure receiving rod by means of a releasing cylinder 49 at the mold opening and closing position and consequently the pressure receiving rod 40 is set free. Accordingly, the time up to mold opening can be properly held by means of the pressures of the springs.

Description

Detailed Description of the Invention [Field of Industrial Application] This invention relates to a rotary injection molding machine capable of injection molding rubber, synthetic resin, etc. by intermittently circulating a plurality of molds. It is something.

[Prior Art] A conventional molding machine of this type has a machine base 1 as shown in FIG.
A pressure receiving plate 2 is provided above and supported by a tie bar 3 and a column 4 at the center of the machine base, and rotary plates 6.
6 are provided in parallel, and the upper mold holding plate 8 and the lower mold clamping plate 9 are inserted vertically movably through a plurality of tie bars 7.7 that are narrowed across the upper and lower rotary plates 5 and 6, and the mold clamping is performed. constitutes a unit.

゛ Furthermore, an opening/closing rod 10 is provided below the mold clamping plate 9, and a track rail 11 on the machine base is attached to the side of this opening/closing rod 10.
A cam follower 12 is provided that moves in contact with the
A spring 1 for keeping the mold closed is installed between the upper rotating plate 5 and the mold holding plate 8.
3 to prevent the mold 14 from opening during rotational movement.

In such a rotary molding machine, injection is performed from the side of the mold after the mold is clamped via the opening/closing rod 10 by a mold clamping cylinder 15 provided in the machine stand. Also, to open the mold, use the hook 1e at the tip of the piston of the mold opening cylinder 15 inside the machine.
The cam follower 12 is locked.

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, the cam follower 12 receives the force of the spring 13 and rolls on the track rail 11, so the life of the cam follower 12 and the track rail 11 is short, and the mold closes when used for a long period of time. Retention is impaired and flakes etc. are likely to occur.

In addition, since the position of the cam follower 12 is offset from the center of the mold clamping, an uneven load is applied to the mold clamping plate, causing rapid wear of the tie bar bushings, impairing mold closing accuracy, and making it impossible to obtain products with high molding accuracy. It disappears.

Furthermore, since the mold clamping unit is constructed using upper and lower rotary disks, maintenance is difficult, and in some cases, the rotary disks may have to be disassembled.

This invention was devised in order to solve the above-mentioned conventional problems, and its purpose is to eliminate the need to use a cam follower to keep the mold closed, to ensure that the mold is kept closed by spring pressure, and to use a mold clamping unit. The purpose of the present invention is to provide a rotary injection molding machine that is easy to maintain.

[Means for Solving the Problems] The feature of the present invention according to the above object is that a mold clamping stationary plate having a mold clamping cylinder installed therein is provided above the mold clamping position of the pressure receiving plate on the machine stand.
A rotary table is supported by a tie bar and a pillar at the center of the pressure receiving plate, and a rotary table is supported by a bearing on the pressure receiving plate, and a lower fixed plate and an upper fixed plate are integrally attached to a predetermined location of the rotary table by means of a tie bar. Multiple connected mold clamping units are installed vertically with the lower fixed plate fixed,
The mold clamping unit is made up of a mold clamping plate with a pressure receiving rod and a central opening/closing rod located directly below the ram of the mold clamping cylinder extended at the top, and a plurality of spring members interposed below the clamping plate to make it movable. The connected mold mounting plate is inserted through the tie bar so as to be movable up and down, and the shutter plate of the pressure rod is slidably provided below the upper fixed plate.

[Operation] In the above configuration, the mold clamping unit rotates by a predetermined angle together with the rotary table. At the mold clamping position, the clamping plate is pressed through the mold opening/closing rod by the operation of the mold clamping cylinder, and the mold is clamped.

The mold clamping force of the mold after injection molding is applied to the spring member between the mold clamping plate and the mold mounting plate until the shutter plate, which restrains the pressure rod and receives the reaction force of the spring member, is removed from the top end of the pressure rod. It is maintained at a moderate level by the elastic force of.

[Example 1] The rotary injection molding machine of the present invention will be described below with reference to Figs. 1 to 4.
This will be explained in detail with reference to the embodiments shown in the figures.

21 in the figure is a pressure receiving plate provided on the stepped part of the machine base 22. Above the mold clamping position of the pressure receiving plate 21, a mold clamping stationary plate 24 with a mold clamping cylinder 23 installed therein is connected to a tie bar 25 in the center of the pressure receiving plate. It is supported by a pillar 26.

Moreover, on the pressure receiving plate 21, there is a donut-shaped rotary table 28 which integrally has a large-diameter ring gear 27 on the back side. It can be set freely.

The annular gear 27 of the rotary table 28 meshes with the gear 30 of the intermittent rotation motor 29 attached to the pressure receiving plate 21.
The rotary table 28 is rotated in one direction by the motor 29 while repeating stops every 90 degrees.

31 is a mold clamping unit 2), which includes a lower fixing plate 32 and an upper fixing plate 3.
3 are integrally connected by tie bars 34 at each corner, and the tie bars 33 are stacked with a mold clamping plate 35 and a plurality of spring members 36 are interposed on the lower side of the mold clamping plate, as shown in FIG. , and a mold mounting plate 38 movably connected by a pin 37, are inserted therein so as to be vertically movable, and opening/closing rods 39 are located at the center and both sides of the upper part of the mold clamping plate 35, passing through the upper fixing plate 33. and the pressure-receiving rod 40, and furthermore, the shutter plate 41 of the pressure-receiving rod 40 is attached to the upper fixed platen 3.
It has a structure in which a guide plate 42 is provided on the lower side of the guide plate 3 so as to be slidable thereon.

The required number of mold clamping units 31 are vertically installed on each of the four sides of the rotary table 28 with lower fixing plates 32 fixed thereto, and the upper fixing plate 33 is rotatably attached to the support 26. They are mutually connected by a member 44 to a retaining ring 43 fitted therein.

Reference numeral 45 denotes a mold opening/closing cylinder, which is mounted downward on a frame 46 provided above the mold clamping unit stop position adjacent to the mold clamping position. At the lower end of the piston of this mold opening/closing cylinder 45, a guide rod 48 is provided and a member 47 is attached to which the neck 39a at the upper end of the opening/closing rod is introduced from the side and fitted.

Reference numeral 49 denotes a cylinder for opening the shutter plate 41, which is horizontally attached to the column 26, and a retainer 5° with the rear end of the shutter plate is attached to the tip of the piston.

51 is a mold, which is a lower fixed platen 32 of the mold clamping unit 31;
and the mold clamping plate 33. Although not shown in the drawing, in this mold 51, the side part of the upper mold is formed in a recess together with the mold clamping plate 35 and the mold mounting plate 38, and the nozzle part of the injection cylinder 52 is inserted into the recess from the side. After inserting as shown,
The piston 54 of the cylinder 53 on the nozzle part is brought into contact with the receiving member 55 of the upper fixed plate 33, and the reaction force is used to touch the nozzle.

In the above structure, each mold clamping unit 31 rotates by 90 degrees together with the rotary table 28. At the mold clamping position, the ram 23a of the mold clamping cylinder 23 presses the mold clamping plate 35 via the mold opening/closing rod 38, thereby clamping the mold 51.

When the injection tube 52 retreats and leaves the mold 51 after injection is completed, the ram 23a rises to its original position due to rotation.
Although the pressing force is removed, the clamping force of the mold 51 is maintained by the spring member 26.
It is maintained at an appropriate level due to its elasticity. This elastic force is maintained until the mold clamping unit 31 reaches the mold opening/closing position, and the shutter plate 41, which restrains the pressure receiving rod 4o and receives the reaction force of the spring member 26, is activated by the opening cylinder 49 at the mold opening/closing position. The pressure receiving rod 40 is removed from the top end of the pressure receiving rod.
It is released when the character becomes a free staff.

After that, the opening/closing rod 39 is moved by the mold opening/closing cylinder 45.
The mold 51 is pulled up as shown in the figure, and the mold 51 is opened. After the molded product is taken out, the mold is closed by the opening/closing cylinder 45, the shutter plate 41 is further pushed in by the opening cylinder 49, the pressure receiving rod 4o is restrained again, and the mold clamping unit is in the mold open position. 31 is transferred to the mold clamping position by the rotary table 28.

Therefore, in the molding of rubber, etc., strong mold clamping is required only during injection molding, and a small mold clamping force is sufficient during vulcanization and curing, so that the time until mold opening can be maintained at an appropriate level by spring pressure.

[Effects of the Invention] As described above, the present invention includes a mold clamping stationary platen 24 having a mold clamping cylinder 23 installed above the mold clamping position of the pressure receiving plate 21 on the machine stand.
A rotary table 28 is supported by a tie bar and a pillar 26 at the center of the pressure receiving plate, and a rotary table 28 is supported by a bearing on the pressure receiving plate. 33 are integrally connected by tie bars 34,
Since the lower fixed plate 32 is fixed and installed vertically, and the mold is clamped vertically from above, the entire lower fixed plate receives the mold clamping force, and the pressure on the mold clamping unit is equalized. Therefore, unlike conventional molds, unbalanced loads do not occur during mold clamping.

In addition, a mold clamping plate 35 has a pressure receiving rod 40 and a central opening/closing rod 39 located directly below the ram of the mold clamping cylinder 23 extended at the top, and a plurality of spring members 36 are interposed below the mold clamping plate 35 so as to be freely movable. The connected mold mounting plate 38 is connected to the tie bar 34.
The shutter plate 41 of the pressure receiving rod 4o is slidably provided on the lower side of the upper fixed platen 33 to constitute the mold clamping unit 31, and the mold clamping unit 31 is used for mold clamping other than injection molding.
Since this is done using a spring member between the mold clamping plate and the mold mounting plate, the spacing between the spring members can be set arbitrarily depending on the mold, and even if the vulcanization and curing time is long when molding rubber etc.
The spring pressure allows the mold to be held in a well-balanced manner with an appropriate amount of force.

Furthermore, the mold clamping unit is simply installed on the rotary table, and the mold opening interval can be set sufficiently, so molds are no longer limited to a constant thickness as in the past, and maintenance is reduced. It has features such as being easy to perform.

[Brief explanation of the drawing]

1 to 4 show one embodiment of the rotary injection molding machine according to the present invention, in which FIG. 1 is a developed side view taken along the line ■-■ in FIG. The figure is a plan view of the shutter plate part, Figure 4 is a vertical cross-sectional view of the mold clamping plate and mold mounting plate,
FIG. 5 is a schematic longitudinal sectional side view of a conventional rotary injection molding machine. 21......Pressure panel 22...
...Machine base 23...Mold clamping cylinder 2
4...Mold clamping fixing plate 25...
・Tie bar 26・・・・・・・Post 27・・
...... Ring gear 28 ... Rotating table 2θ ... Motor 31 for intermittent rotation...
・・・・・・Mold clamping unit 32・・・・・・Lower fixing plate 33・・・・・・Upper fixing plate 34・
......Tie bar 35...Mold clamping plate 36...Spring member 38...
......Model mounting plate 39...Opening/closing rod 40...Pressure rod 41...Shutter plate 51...
... Mold patent applicant Nissei Jushi Kogyo Co., Ltd. Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] Above the mold clamping position of the pressure plate on the machine stand, a mold clamping stationary plate with a mold clamping cylinder installed therein is supported by tie bars and a pillar in the center of the pressure plate, and a rotary table is mounted on the pressure plate using bearings. A plurality of mold clamping units, in which a lower fixed plate and an upper fixed plate are integrally connected by tie bars, are installed vertically at predetermined locations on the rotary table, with the lower fixed plate fixed to the rotary table. The clamping unit consists of a mold clamping plate with a pressure receiving rod and a central opening/closing rod located directly below the ram of the mold clamping cylinder placed on the top, and a plurality of spring members interposed below the clamping plate so as to be movably connected. 1. A rotary injection molding machine, comprising: a mold mounting plate inserted through a tie bar so as to be movable up and down; and a shutter plate for a pressure receiving rod slidably provided below an upper fixed plate.