JPS6153213B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an injection molding machine, and more specifically, a mechanism common to conventional molds is incorporated into a fixed platen or a movable platen, so that only the essential parts of the fixed platen and the movable platen are used. The present invention relates to a synthetic resin injection molding machine that can quickly and easily replace molds in order to accommodate a wide variety of low-volume production by fitting molds of standard sizes in a compatible manner.

Conventionally, synthetic resin injection molding machines have installed a mold between a fixed mold mounting board that opens and closes and a movable mold mounting board, and a nozzle touches the mold to inject the molded product through the resin path inside the mold. The cavity is filled with molten resin by injection.

Therefore, it is necessary to form a resin channel in the mold, install a temperature control device, and make these structures pressure-resistant, which also requires a mounting plate to be attached to the mold mounting board, making the entire mold difficult to install. , the size is larger than the molding cavity of the mold,
It's becoming very heavy.

Therefore, the work of loading and unloading the molds onto the mold mounting board becomes large-scale and time-consuming, and if automation is attempted, the equipment would have to be large-scale.

In particular, in recent years, the applications of molded products have become more diverse, and there is a tendency to keep molded product inventories to a small amount. This has created the need for high-mix, low-volume production, shortening mold change time, reducing mold costs, and reducing mold costs. Various problems such as stock space problems are occurring.

In view of the above points, the purpose of this invention is to reduce the size and weight of the mold, simplify the structure and make it inexpensive, and facilitate installation and removal to shorten time and automate production, and to be able to cope with high-variety, low-volume production. Of the fixed mold and movable mold in the set, drill a fixed mold fitting hole in the fixed plate to fit the fixed mold, and a movable mold fitting hole to fit the movable mold in the movable plate. Another object of the present invention is to provide an injection molding machine characterized in that a resin path is formed in the stationary platen from the nozzle touch portion to the stationary mold fitting hole. Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a mechanical explanatory diagram showing a state in which a mold is attached to a conventional injection molding machine, in which a movable mold mounting plate 3 is guided to a tie bar 4 by a mold clamping cylinder 1 via a mold clamping ram 2. advance and retreat.

A fixed mold 6 is fixed to the fixed mold mounting plate 5,
A movable mold 7 is fixed to the movable mold mounting plate 3.

8 is a nozzle, and 9 is a resin path, which passes from the nozzle 8 through the inside of the fixed mold 6 and communicates with the cavity 10.

Reference numeral 11 denotes a projecting pin, which is provided integrally with the projecting plate 12 and moves forward and backward by a projecting cylinder 13.

Embodiments of this invention are shown from FIG. 2 onwards.
The figure shows the state at the time of mold clamping and injection filling, and numeral 15 denotes a fixed plate, which is fixed at a predetermined position of the tie bar 4.

Reference numeral 16 denotes a movable platen, which is guided by the mold clamping cylinder 1 via the mold clamping ram 2 to the tie bars 4, moves forward and backward, and opens and closes between it and the fixed platen 15.

A fixed mold 17 is fitted into a fixed mold fitting hole 18 bored in the fixed platen 15.

A movable mold 19 is fitted into a movable mold fitting hole 20 formed in the movable platen 16.

The fixed mold 17 and the movable mold 19 are combined to form a mold 14.

Reference numeral 10 denotes a cavity of the molded product, which is provided between the fixed mold 17 and the movable mold 19 and communicates with the resin channel 9 provided in the fixed mold 17 and/or the movable mold 19.

Reference numeral 21 denotes a hot sprue portion that penetrates from the outside of the fixed platen 15 into the fixed platen 15 to reach the resin path 9, and the nozzle 8 approaches and separates from the nozzle touch portion 22 at the other end.

Reference numeral 23 designates an ejector pin, the tip of which is inserted into the movable mold 19 and faces the cavity 10, and the rear end of which protrudes to the outside of the movable mold 19 and is provided with a pressing plate 24. A spring 25 is elastically loaded between the movable mold 24 and the movable mold 19 in the direction of extension.
The ejecting pin 23 is provided in the movable platen 16 and is operated by an ejecting actuating device 26 that is moved forward and backward by the ejecting cylinder 13.

A runner ejecting pin 27 is attached to the ejecting actuating device 26 and moves forward and backward as one.

FIG. 3 shows the state after the mold is opened and the molded product is ejected, with the nozzle 8 retracted and the ejection actuating device 26
is pushed out, and the ejection pin 23 and runner ejection pin 27 are ejected.

FIG. 4 is a view taken along the arrow -' in FIG. 3, and shows the movable platen 16 and the movable mold 19 fitted therein. Here, the number of molds, their arrangement, the shape of the resin path, and their arrangement can be set as appropriate. Also, in this example, the case of four cavities was shown, but
By cutting off the resin path to the mold part, 3, 2,
It is also possible to take one piece.

Furthermore, the runner part 45 can be provided on the fixed plate 15 or the movable plate 16, or the runner part 45 can be provided on the fixed plate 15 or the movable plate 16.
5 and the movable platen 16.

FIG. 5 shows another embodiment, in which the parts corresponding to the fixed platen 15 and movable platen 16 in the previous embodiment are respectively replaced with a fixed mold holding plate 28 including a fixed mold fitting hole 18 and a fixed plate 15'. Also, there is a movable mold fitting hole 20.
The movable mold holding plate 30 and the movable plate 16' including the movable mold holding plate 30 and the movable plate 16' can be separated and assembled with bolts 31 to perform exactly the same functions as the fixed plate 15 and the movable plate 16 of the previous embodiment. In addition, in this way, the machining work of the fixed platen 15 and the movable platen 16 can be facilitated, and the installation of the temperature control device, the heat insulating means, etc. can also be facilitated.

FIGS. 6A and 6B show a mold that is fitted into the fixed platen 15 and the movable platen 16, and this mold is a kind of standard semi-finished product, and the cavity can be suitably machined according to the molded product. A is the b-b' cross section of B, and B is the cross section of A
A cross-section taken along line a-a' is shown.

Reference numeral 32 denotes a guide pin, which is fixed to the movable mold 19 and stands up in the direction of the fixed mold 17, and when the mold is clamped, the guide pin 3 provided on the fixed mold 17
Insert into 3.

The ejecting pin 23 is fixed to a pressing plate 24 and a spring receiving plate 35 which are integrally assembled with bolts 31 using a collar 34 as a spacer, and the tip thereof is attached to the movable mold 1.
9 to face the cavity 10, press the pressing plate 24
As the protrusion actuating device 26 advances and retreats, the protrusion actuator 26 reciprocates between the surface position of the cavity 10 and the protrusion position.

The stopper pin 36 is fixed to a contact plate 37 provided on the back surface of the movable mold 19, and the spring receiving plate 35 is loosely inserted into the stopper pin 36, and its tip is stopped at a fixed length, thereby serving as a stopper at the backward limit of the spring receiving plate 35.

A spring 25 is interposed between the spring receiving plate 35 and the abutting plate 37, and when the protruding actuating device 26 moves forward and presses the abutting plate 24, the spring receiving plate 35
moves forward, the spring 25 is compressed as the ejector pin 23 protrudes, and when the ejector actuator 26 retreats, the spring receiving plate 35 retreats due to the expansion of the spring 25, and the tip of the ejector pin 23 touches the surface of the cavity 10. Move back to a position that matches your position.

The length of the protruding pin 23 is determined appropriately according to the cavity of the molded product.

An embodiment of the means for fixing this mold to the fixed platen 15 or the movable platen 16 is shown in FIGS. 7C and 7D.

The fixing means in Figure C is the fixed platen 15 or the movable platen 16.
A ball hole 38 is provided in the inner wall of the mold fitting hole, and after inserting a spring 38a into the ball hole 38, a ball 39 is inserted so as to spring outward. Load. On the other hand, an extension recess 40 of the ball hole 38 is provided on the outer circumferential wall of the mold 14, and when the mold 14 is completely fitted into the fixed platen 15 or the movable platen 16, the ball 39 is pushed out slightly and the ball hole 38 is pushed out. The ball 39 contacts the outer end of the mold 1 and the inner wall of the recess 40 of the mold 1.
4 is locked so that it does not slip out from the fixed platen 15 or movable platen 16. To release the lock, use the pin hole 38b.
This is done by inserting a pin from the top and pushing back the ball 39.

Alternatively, as shown in FIG. Type 14
may be fixed so as not to move in the axial direction.
In this case, the engagement hole portion of the mold 14 is the same as that of the mold 1.
A groove in the outer circumferential direction of No. 4 may also be used.

The present invention is constructed as described above, and the fixed mold 17 and the movable mold 19 are fitted into the fixed mold fitting hole 18 of the fixed platen 15 and the movable mold fitting hole 20 of the movable platen 16, respectively. By fixing and clamping the mold, the resin injected from the nozzle 8 passes through the hot sprue section 21, the runner section 45, the gate section 46 of the mold, and is filled into the cavity 10. After a predetermined period of time, the mold is opened, and as the ejection actuating device 26 moves forward, the ejector pin 23 in the movable mold 19 releases the molded product and the runner together with the runner ejector pin 27.

When replacing the mold 14, open the mold, release the fixing means to take out the fixed mold 17 and the movable mold 19 that are fixed to the fixed platen 15 and the movable platen 16, respectively, and replace the same mold with a different type. It is fitted and fixed using a method.

As described above, according to the injection molding machine of the present invention, common mechanisms in conventional molds are incorporated into the fixed platen or movable platen on the injection molding machine side, and the mold is equipped with only the minimum necessary configuration as a mold. , the mold becomes extremely compact and lightweight. Therefore, for example, whereas conventional molds weighing hundreds of kilograms had to be loaded and unloaded, according to the present invention, it is sufficient to load and unload molds weighing only a few kilograms, making it easier to replace manually. Of course, even when using an automatic machine, the process can be carried out extremely quickly and easily without the need for a large-scale automatic machine.

In addition, the sprue that was conventionally built into the mold and cooling piping for replacing the mold are now installed on the molding machine, making it possible to make the mold smaller and lighter. As described above, since the mold is small, the manufacturing cost of the mold is low, it can be manufactured in a short period of time, it does not take up space when kept in stock, and it is easy to transport. Furthermore, since it is a standard size, only the positions of the cavity and ejector pins need to be processed to correspond to the molded product, and a preliminary set of semi-finished molds can be prepared.

Furthermore, the molds are fitted inside the fixed and movable plates, unlike conventional methods in which they are mounted horizontally on the fixed and movable mold mounting plates, so the mounting bolts are not likely to loosen and fall. There is no risk of damage to the mold or damage to the mold, and no unnatural load is applied to the movable platen, so the precision life of the molding machine is improved.

Furthermore, in the case of conventional large molds, it is necessary to adjust the temperature before installing it in the molding machine, but in the case of this invention, the temperature of the fixed platen and the movable platen is constantly adjusted. There is almost no need to do so.

Furthermore, since the hot sprue is provided on the stationary platen, there are few runner parts and resin is not wasted, thereby providing an injection molding machine suitable for small-scale production of a wide variety of products.

Although the present invention has been variously explained above with reference to preferred embodiments, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. It is.

[Brief explanation of the drawing]

The drawings show an embodiment of an injection molding machine according to the present invention, and FIG. 1 is a cross-sectional explanatory diagram of a conventional injection molding machine. 2 and 3 show an embodiment of the injection molding machine according to the present invention, FIG. 2 is a cross-sectional explanatory view showing the state of the injection molding machine when the mold is clamped and injection is filled, and FIG. 3 is a mold FIG. 4 is a cross-sectional explanatory view showing the state after opening and protruding the molded product, and FIG. 4 is a view taken along the -' arrow in FIG. 3. FIG. 5 is an explanatory cross-sectional view showing another embodiment of the injection molding machine according to the present invention. FIG. 6 is an explanatory cross-sectional view of a set of molds, in which figure A is a sectional view taken along line b-b' in figure B, and figure B is a view taken along arrow a-a' in figure A. FIG. 7 is an explanatory cross-sectional view showing means for fixing the mold to a fixed platen or a movable platen. 1...Mold clamping cylinder, 2...Mold clamping ram, 3
...Movable mold mounting plate, 4...Tie bar, 5...Fixed mold mounting plate, 6...Fixed mold, 7...Movable mold, 8...Nozzle, 9...Resin path, 10... Cavity, 11... Ejection pin, 12... Ejection plate, 13... Ejection cylinder, 14... Mold, 1
5... Fixed plate, 15'... Fixed plate, 16... Movable plate, 16'... Movable plate, 17... Fixed mold, 18
...Fixed mold fitting hole, 19...Movable mold, 20...
...Movable mold fitting hole, 21...Hot sprue part,
22... Nozzle touch part, 23... Ejection pin,
24...Press plate, 25...Spring, 26...
Ejection actuation device, 27... runner ejection pin,
28... Fixed mold holding plate, 30... Movable mold holding plate, 31... Bolt, 32... Guide pin, 33
...Guide bushing, 34...Color, 35...
Spring receiving plate, 36... Stopper pin, 37...
Backing plate, 38...Ball hole, 38a...Spring, 38b...Pin hole, 39...Ball, 40...
... recess, 42 ... engagement hole, 43 ... actuator, 44 ... engagement element, 45 ... runner part, 46
...Gate section.

Claims (1)

[Scope of Claims] 1. A fixed mold fitting hole into which the fixed mold of a set of fixed mold and movable mold is fitted, and a movable mold fitting hole into which the movable mold is fitted in the fixed plate. An injection molding machine characterized in that a movable platen is provided with holes, and a resin path is formed in a fixed platen from a nozzle touch portion to a fixed mold fitting hole. 2. The injection molding machine according to claim 1, wherein a plurality of sets of fixed mold fitting holes and movable mold fitting holes are provided corresponding to a plurality of sets of fixed molds and movable molds. 3. An injection molding machine according to claim 1, in which the resin path comprises a runner section provided on a parting line of a fixed plate and/or a movable plate, and a hot sprue section extending from a nozzle touch section of the fixed plate to the runner section.