JPS60159019A - Mold of injection molder - Google Patents

Abstract

PURPOSE:To make suitable a mold for molding different items in small amounts and to lower the cost of the mold, by releasing the clamping between a fixed side mold jig and a movable side mold attaching jig thereby allowing the replacement of the molds. CONSTITUTION:When the mold is to be replaced, first the parting faces of the mold sections 16, 21 are opened, clamp arms are moved forward toward each other a little, the engagement of the peripheral sections of the fixed side mold attaching jig and the movable side mold attaching jig 14, 20 is released, then the clamping arms are rotated outward, the attaching jigs 14, 20 having the mold sections 16, 21 and an ejector mechanism 18 mounted thereon can be released from the attaching tables 11, 17, the mounted mold sections 16, 21 are removed, other molds having different contoured patterns are inserted into mounting holes, and at the same time other corresponding back plates, ejector pins, and pin plates are mounted for the replacement.

Description

[Detailed description of the invention] The present invention relates to the structure of a mold for an injection molding machine.

A mold for a general injection molding machine consists of a mold base, a cavity part processed or incorporated into the mold base, a part of the runner and a gate part, a device for ejecting the molded product, a temperature control part (cooling device), and a molding part. The fixed side is fixed to the fixed plate of the molding machine and is the side where the raw material is injected, and the movable side is attached to the movable plate of the molding machine to attach it to the machine. It is designed to be attached and detached.

For this reason, if the shape, size, etc. of the molded product are different, the entire mold including the mold base must be newly manufactured, making the manufacturing cost of the mold extremely high.

In addition, conventional molds are extremely large compared to the molded product,
Not only does it take a lot of time and effort to attach and detach the injection molding machine, but mold manufacturing costs account for a large proportion of the cost of molded products molded with such molds, so it is difficult to produce high-mix, low-volume products. Nowadays, as the number of requests increases, there are cases where it is not worth the cost.

In view of the current state of conventional molds as described above, the present invention is an injection molding method that can reduce the mold cost to less than that of conventional molds and eliminates the need to replace the entire mold base unlike conventional products. This was made for the purpose of providing a mold for an injection molding machine, and its structure includes a part of the runner that can be divided on a fixed platen for an injection molding machine, and a part of the runner that can be divided when the mold is opened. A fixed-side mount whose front part slides forward from the surface and a runner ejector mechanism related to a part of the runner are provided as machine-side parts, and the fixed-side mount has a fixed-side mold with standardized dimensions and shape. A fixed side mold jig with a replaceable part is removably clamped, and a movable side mounting base and a product ejector mechanism are provided as machine side parts on a movable platen in an injection molding machine, and a movable side mounting base and a product ejector mechanism are provided as machine side parts. 1 dimension.

A movable mold mounting jig, which has a movable mold part with a standardized shape that can be replaced, is removably clamped. It is characterized by being able to be exchanged.

Next, an example of implementation of the present invention will be explained with reference to the drawings.

In Fig. 1, 1 is a fixed plate in an injection molding machine, and 2 is a movable plate.The fixed plate 1 is fixedly installed on a mounting base 1a on the machine side, and the movable plate 2 penetrates the fixed plate 1. It is linked to a mold clamping toggle 3 via an operating rod 2a.

Reference numeral 3a denotes a pneumatic cylinder connected to the toggle 3. When the cylinder 3a is actuated, the toggle 3 expands and contracts, and the movable platen 2 approaches and moves away from the fixed platen 1.

Reference numeral 4 denotes a raw material injection section disposed above the fixed platen 1, which is composed of a raw material storage and supply hopper 4a, an injection pneumatic cylinder 4b, an injection plunger 4c, a heating cylinder 4d, and an injection nozzle 4e. In addition, 4f is a support to which the above-mentioned structural members 48 to 4e are attached, and is erected on the upper part of the fixed platen l.

Since the mold of the present invention is attached to the fixed platen 1 and the movable platen 2, this will be explained with reference to FIG. 2. In Fig. 2, the upper half of the center line is the mold closed I]! , the lower half shows a planar cross section of the mold of the present invention when the mold is opened.

Reference numeral 11 denotes a fixed side mounting part that is mounted on the front side of the fixed platen 1 toward the movable platen 2 side, and the mounting part is attached to the rod of the pneumatic cylinder 12 provided on the fixed bracket 3b formed on the back side of the fixed platen 1. By being attached to the front end of the fixed plate 12a, it can be brought into close contact with and separated from the fixed plate 1.

12c is a mounting plate for rods 12a and 12b which also serve as pistons.

Reference numeral 11a denotes a mounting pedestal provided on the back side of the fixed side mount 11 by dividing the mount 11 in the thickness direction, through which the rod 12a is loosely inserted. When it is in close contact with the fixed platen 1 (when the mold is closed), it is integrated with the mounting base 11, and when the mounting base 11 is separated from the fixed platen 1 by the advance of the rod 12a (when the mold is opened), the above-mentioned mounting The pedestal 11a remains in close contact with the fixed platen 1.

Reference numeral 13 denotes a spool bushing having a planar tapered shape attached to the fixed side mounting base 11 by penetrating the mounting base 11a, and a spool bushing 13 communicating with the injection nozzle 4e formed on the dividing surface of the mounting base 11 and the base 11a. A runner portion 13a communicating with the portion 11C is formed (see FIGS. 3 and 4). Here, the reason why the bushing 13 is tapered is because
This is to ensure the accuracy of the assembly of the mounting base 11 and its base 11a when the mold is opened and closed.

Furthermore, in the mounting base 11 and its pedestal 11a, two runner ejector pins 13b are inserted on and above the shaft of the bushing 13, penetrating through the mounting base 11 and the pedestal 11a. When the mold is opened, the ejector plate 13c is pushed by the rod 12b, which is shorter than the rod 12a of the cylinder 12, and the front side of the pin 13b is pushed out, so that only a portion of the runner of the molded product is ejected. 13d is a guide pin of the plate 13c, and 13e is a return spring provided on the guide pin 13d between the plate 13c and the stationary plate 1.

14 is a clamp 15 on the front side of the fixed side mounting base 11.
This is a fixed-side mold mounting jig provided for so-called one-touch attachment/detachment, and a mounting hole 14a for the fixed-side mold part is formed in the center of the jig. Here, the mold part 16 on the fixed side
is attached to the jig 14 from the rear surface of the attachment hole 14a.

In this embodiment, the mounting hole 14a is a round hole with a step, and therefore the mold part 16 also has a flange part 16 that matches the step of the hole.
Although the shape and structure of the attachment hole 14a are not limited to this embodiment, any other configuration may be used.

Incidentally, the mold part 16 is formed with a runner part 16b that communicates with the runner part 11c on the side of the mount 11 and has a pinpoint gate at its tip.

Since the clamp 15 pulls the mounting jig 14 onto the mounting base 11 side on both sides and tightens it, the claw member 15b at the tip of the arm pivoted to the mounting base 11 by an eccentric shaft 15a moves the mounting jig 14 by rotating the shaft. The outer side 14b of the mounting jig 14 is pulled rearward to firmly bring the rear surface of the mounting jig 14 into close contact with the front surface of the mounting base 11.

As a result, the mold part work 6 has its mounting jig 14 and mounting base 11
It will be integrated with.

If the eccentric shaft 15a is returned to its original position, the clamp 15 will be loosened and the claw member 15b can be removed from the outer side 14b of the mounting jig 14.

As described above, on the fixed platen 1 side, the mold constituent members except the mold mounting jig 14 and the mold part 1G are fixedly provided on the fixed platen 1, that is, in a non-replaceable manner.

On the other hand, the movable platen 2 side also has the same configuration as the fixed platen 1.

That is, the front side of the movable platen 2 (the side facing the fixed platen 1).

A movable mounting base 17 equipped with a product ejector mechanism 18 inside is fixed to the mounting base 17, and a clamp 19 having the same structure as the fixed clamp 15 is attached to the front surface of the mounting base 17.
A mold mounting jig 20 is provided, which is attached and detached by a mold mounting jig 20, and a mold part 21 is attached and detached to this jig in the same manner as that of the fixed side.
is installed. In addition, the above mounting jig 14.2
0 is equipped with a temperature control circuit.

In FIGS. 2 to 4, reference numeral 20a denotes a mounting hole of the mold part 21 carved from the mold 21b of the molded product, and is a stepped hole similar to the hole 14a on the fixed side. 20b is a claw member 19b of the clamp 19
19a is the outer edge of the mounting jig 20 that engages with the clamp 19
It is the eccentric axis of

Further, 20c is the rear plate of the mounting jig 20, 113f
, 18g are fixed to each other by bolting, and support the ejector mechanism 18 on the mounting base 17 with a support pin 18h interposed between it and the rear plate 20c;
18a is a pneumatic cylinder provided on the movable platen 2 as an operating drive source for the ejector mechanism 18; 18b is a piston rond thereof; 18c is attached to pin plates 18d and 18e loosely inserted into the support pin 18h; The product ejector pin 18i, which passes through the face plate 20c and the mold part 21 and reaches the surface of the mold 21b when the mold is closed, is the pin play 1.
~18e, the rear side, that is, the pneumatic cylinder 18a
18j is an operating pin of the ejector mechanism 18 located on the front surface of the piston rod 18b, and 18j is the operating pin of the ejector mechanism 18 located on the front surface of the piston rod 18b.
This is a return spring inserted between 0c and ejector plate 18d.

With the above configuration, the movable side mounting base 17 is fixedly provided as a mechanical component on the injection molding machine side on the movable platen 2 side as well, and the mold part 21 and the ejector mechanism 18 are normally attached and detached. Not only the mounting jig 2o, but also the mold part 21. Rear plate 2
0c, ejector bin 18c.

Only the pin plate 18d needs to be replaced.

An example of the operation of the mold of the present invention constructed as described above and the procedure for replacing the mold parts 16 and 21 are as follows.

First, when the mold is closed, the pneumatic cylinder 3a operates and the toggle 3
By extending the movable platen 2 attached to the operating rod 2a and drawing it toward the fixed platen 1 side, the mold parts 16 and 21 are brought into close contact with each other and the raw material can be injected.

At this time, each ejector pin 13b, 18c has returned to its original position by the action of its return spring 13e, 18j, and each cylinder 12, 18 is also in a position where its piston is retracted (see FIG. 3).

When the mold is in the above state, when resin is injected from the runner part 11c side, the resin is injected into the runner part 13a.

16b, it is filled into the mold 21b carved in the mold part 21, and the injection process is completed after a predetermined mold temperature control, and when the molded product is cured, the mold is opened. That is, the pneumatic cylinders 3a and 12 operate, pushing the operating rod 2a and the piston rod 12a forward via the toggle mechanism, and the movable platen 2 and the members attached thereto, the fixed side mounting base 11 and the members attached thereto. is separated from the fixed platen 1 and the members 11a and 13 attached thereto, so the runner part 11. The dividing plane of lla is opened (see Figure 4).

At this time, the runner part Q of the molded product M in Fig. 5 (b) is
By being engaged with the hook portion 13f at the tip of the runner ejector pin 13b on the axis of the spool bush 13, the runner portion β remaining on the fixed side separated from the molded product M continues to The rod 12c placed on the advancing piston i2c pushes out the plate 13c of the runner ejector pin 13b, thereby releasing the ejector pin 13b.
The mounting pedestal 11 is projected forward and opened by the previous operation.
It will fall downward through the gap formed between a and the mounting base 11.

Even after the movement of the fixed side by the cylinder 12 ends, the movement of the movable side by the actuating rod 2a continues, so next the mold part 16.
21 product forming surfaces are opened. At this point, the pinpoint gate part of the mold part 16 has been cut between the molded product M and the runner part μ, so the molded product M is preliminarily separated from the molded part M by a movable side metal plate that is designed to have better bite of the molded product. It remains in the mold 2Ib of the mold part 21.

Therefore, the molded product M is transferred to the cylinder 18a in the product ejector mechanism 18, which is started after the mold opening operation is completed.
The piston 18b is ejected from the mold 21b by the advancing movement of the piston 18b.

That is, since the piston 18b pushes the actuating rod 18i from behind, the tip of the ejector pin 18c provided on the front side of the pin plate 18d projects the molded product M in the mold 21b forward.

In this way, the mold of the present invention, in which the molded product M and the runner part Q separated from it are respectively projected separately, is in a state as shown in FIG. Therefore, when the cylinder 12.18a is returned to its original state from this state, the ejector pins 13b, 18c will return to their original positions by their respective return springs 13e, 18j, and the open fixed side mounting base 11 and its The pedestal 11a is closed, and the movable platen 2 side is moved to the fixed platen 1 by the return operation of the pneumatic cylinder 3a.
The mold is pulled in toward the side and returns to the mold closed state shown in the third figure.

Therefore, when replacing the mold of the present invention, the machine is placed in the state shown in FIG.
．． 19 eccentric shafts 15a, 19a are rotated to move the respective clamp arms slightly forward in opposite directions, and their claw members 15b,
The outer side 14b of each mounting jig 14.20 of 19b.

20b and then turn the clamp arm outward, the mold part 16.21 and the ejector mechanism 18 are removed.
The mounting jig 14.20 with the
1. ．． 17, so in this state, the mold part 16.21 that was previously installed is removed, and another mold with a different shape is inserted into the mounting hole 14a.

21a, and at the same time replace another rear plate 20c, ejector bin 18c, and pin plate 18d manufactured according to the respective molds. Therefore, the shape of a portion of the runner is the same no matter which mold part is attached.

The present invention is as described above, and molds of different shapes can be molded by replacing only part of the mold part and the component parts of the product ejector mechanism. Also suitable for molding.

Since the labor for replacing molds is significantly reduced compared to the conventional method, this greatly contributes to reducing the cost of molds for molded products.

Therefore, the mold of the present invention is extremely useful as a mold for injection molding machines.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an example of an injection molding machine equipped with an example of the mold of the present invention, and Fig. 2 is a perspective view of an example of the mold of the present invention, with the upper half shown when the mold is closed and the lower half when the mold is opened. 3 is a side sectional view when the mold is closed, FIG. 4 is a side sectional view when the mold is open, FIG. 5 (A) is a side sectional view of a part of the runner, and FIG. 5 (B) is a side sectional view of an example of a molded product. DESCRIPTION OF SYMBOLS 1... Fixed plate, 2... Movable plate, 11... Fixed side mounting base, 11a... Pedestal of mounting base 11, llc... Part of runner of mounting base 11, 12... Empty pressure cylinder, 12
a, 12b...Rod, 12c...Piston and rod mounting plate, 13...Spool bush, 13a...
Part of runner of spool bush, 13b...Runner ejector pin, 13c...Ejector plate, 1
4...Fixed side mold mounting jig, 14a...Mold part 16
mounting hole, 15...clamp, 15a...eccentric shaft,
15b...Claw member, 16...Fixed side mold part, 17.
...Movable side mounting base, 18...Product ejector mechanism, 1
8a... Pneumatic cylinder, 18b... Piston rod, 18c... Product ejector pin, 18d, 18e...
... Pin plate, 18f, 18g... Ejector support plate, 18h... Support pin, 18i... Operating pin,
18j... Return spring, 19... Clamp, 19a... Eccentric shaft, 19b... Claw member, 20...
- Movable side mold mounting jig, 20a... Mounting hole of mold part 21, 20c... Rear plate of mounting jig 20, 21... Movable side mold part, 21b... Mold agent Yoshikuni Koizumi

Claims (1)

[Claims] 1. A fixed platen in an injection molding machine, which has a part of the runner that can be divided and whose front part slides forward from the parting surface of the part of the runner when the mold is opened, and a part of the runner that is related to the part of the runner. A runner ejector mechanism is provided as a machine-side component, and a fixed-side mold jig, which has a replaceable fixed-side mold part with standardized dimensions and shape, is removably clamped to the fixed-side mounting base. For movable platen in molding machine,
A movable side mount and a product ejector mechanism are provided as machine side parts, and a movable side mold mounting jig, which has a replaceable movable side mold part with standardized dimensions and shape, can be attached and detached to the movable side mount. A mold for an injection molding machine, characterized in that the mold is clamped, and the two full mold parts can be replaced by unclamping the two full mold mounting jigs.