JPS61215030A - Injection molding machine - Google Patents

Abstract

PURPOSE:To reduce a quantity of hydraulic oil by shortening an installation space and miniaturizing a side cylinder, by providing a pressure boosting cylinder on a side of a lock mechanism fixing movable platen immovably under a mold clamping state and a stationary platen and providing an injection device movably on the back of a movable platen. CONSTITUTION:When a movable platen 10 is moved leftward and clamping of a mold 34 is performed by a side cylinder 12, an injection device 50 is moved in the same direction as the movable platen 10 under a state wherein the injection device 50 is come into contact with the movable platen 10 and further with a mold 34. Then movable platen 10 and a tie bar 8 are locked by a locking device 18, under this mold clamping state. Then pressure boosting of a pressure boosting cylinder 26 built in the inside of a stationary platen 4 is made to perform by feeding hydraulic oil to the pressure boosting cylinder 26 and clamping of the mold 34 is performed between the movable platen 10 and pressure boosting platen 32. Then a plasticized predetermined resin material is made to inject into a product cavity of the inside of the mold 34 from the injection device under this state.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an injection molding machine, and particularly to an improvement of a mold clamping mechanism in a large 1/1 injection molding machine.

(Prior Art) Conventionally, as an injection molding machine for molding a predetermined plasticized resin material into a molded product of a desired shape, a predetermined mold is placed between a fixed platen and a movable platen, and By moving the movable platen with a mold clamping cylinder provided behind it, the mold is opened and closed, and the mold is further overcome the injection pressure of the resin material injected into the product cavity formed in the mold. While the clamping force is generated by the mold clamping cylinder, an injection device for plasticizing and injecting the resin is placed behind the fixed platen, and the fixed platen and movable platen are connected to each other. A structure in which a resin material is injected from such an injection device into a mold clamped between the two is well known.

However, in a conventional injection molding machine having a structure in which a mold clamping cylinder is provided behind the movable platen to perform mold opening/closing operations and clamping operations, when the machine is enlarged, Inevitably, the type f; The problem is that the length from the cylinder can part 1 (outer end) to the end of the injection device (outer part 1::'r) becomes significantly large, which increases the installation space of the injection molding machine. is inherent.

In addition, in addition to the mold clamping cylinder for high-pressure clamping, multiple side cylinders are installed as a mold one-clamping mechanism in a large injection molding machine, and one piston of each side cylinder is installed. The IS cylinder type plastic tightening device is being proposed, which is connected to a movable platen and has a Q-regiharve installed between the mold clamping cylinder chamber and the tank.
Furthermore, by inserting a total clamping device that generates mold clamping force using the 1~guru link mechanism, a mold opening/closing device that opens and closes the mold 11゛t cylinder part that generates a large mold clamping force, and a block 11. A Hyde I'J mechanical mold clamping device is also known, which is composed of three parts of an 11-lock device that performs mechanical locking.

(Problems) However, the mold clamping mechanisms in these conventional injection molding machines have a number of inherent problems, some of which have been clarified above. For example, in a side cylinder type mold clamping device, the mold clamping cylinder and side cylinder are arranged behind the movable platen, and the main ram of the mold clamping cylinder is fixed to the movable platen. When the mold is opened and closed, the main ram operates as a piston, which inevitably increases the size of the mold clamping cylinder, increases the amount of pressurized oil, and furthermore increases the installation space of the injection molding machine as a whole (long and large). )
The problem still exists.

In addition, in the case of single-glue type mold clamping devices and hydromechanical mold clamping devices, there are major problems such as a large number of parts and a complicated structure. When the thickness of the die changes due to replacement of the die installed in the die, it is necessary to insert a die spacer, ram spacer, etc. in order to apply an effective clamping force to the die. However, there are inherent problems with design constraints such as the distance between the fixed platen and the movable platen (delight) and the minimum mold thickness.

(Solution Means) Here, the present invention has been made to solve such conventional problems, and its characteristics are:
A predetermined mold is disposed between a fixed plate and a movable plate, and a mold opening/closing means for moving the movable plate is provided to open and close the mold, while the mold is in a closed state by the mold opening/closing means. Then, a lock mechanism is provided to fix the movable plate immovably, and a pressure increase cylinder is provided on the fixed plate side, and the pressure increase is applied from the fixed plate side while the movable plate is fixed by the lock mechanism. While the cylinder is used to clamp the mold, an injection device that injects a predetermined plasticized resin material into a product cavity formed in the mold can be moved behind the movable platen. The nozzle of the injection device penetrates the movable platen and comes into contact with the mold, and the resin material is injected.

According to a preferred aspect of the present invention, the mold opening/closing means is constituted by a side cylinder provided between the fixed platen and the movable platen, and the pressure increasing cylinder is provided at the center of the fixed platen. One side of the mold is attached to the pressure increase cylinder 1 of the pressure increase cylinder via a predetermined pressure increase plate, and a pressure increase action is applied to the center of the mold. It looks like this.

In the injection molding machine according to the present invention, the movable injection device, more specifically, the injection molding machine that approaches the fixed platen,
The separable injection device may be configured to be mutually connected to the movable platen and be moved in the same direction as the movable platen moves to open and close the mold, or the injection device may be configured to be separate from the mold opening/closing means. be moved by means of transportation,
A structure that can move forward and backward relative to the movable platen will be adopted.

As described above, the injection molding machine according to the present invention is completely different from the conventional ones in that the injection device is movably provided on the side of the movable platen, that is, behind it, and the movable platen and the injection device are fixed. This structure allows the mold to move forward and backward relative to the platen, while the fixed platen side is equipped with a pressure booster ram or pressure booster cylinder that only needs to be moved a short distance to clamp the mold. Because of this, compared to the conventional structure in which a large mold clamping cylinder is installed behind the movable ηR, its entire length, in other words, from the fixed plate to the outer end of the lug exit device, is shorter. This makes it possible to significantly reduce the remaining length.

Further, while the opening and closing of the mold is performed by a mold opening and closing means such as a side cylinder, the clamping of the mold can be performed by a pressure increasing cylinder different from the mold opening and closing means. Therefore, in order to generate a large mold clamping force (clamping force), a pressure increasing cylinder whose pressure receiving area is shaped like a dog,
It is activated only when pressing, and the small force of a separate mold opening/closing means is used to open and close the mold. This made it possible to significantly reduce the amount of pressurized oil required for tightening.

Furthermore, in the injection molding machine according to the present invention, the conventional one
- The structure is simple and the number of parts is small, rather than a complex structure such as a locking device using a block or a complicated toggle link mechanism such as a glue type mold clamping device or a hydromechanical mold clamping device. It has the advantage of being significantly less than those conventional devices.

Moreover, the injection device is provided on the movable platen side, and the structure allows it to move forward and backward with respect to the fixed platen along with the movable platen, thereby reducing the delay between the fixed platen and the movable platen and the minimum mold thickness of the mold. The design is free, and there is no need for die spacers, ram spacers, etc. as in conventional equipment.In addition, the space of the above-mentioned delight can be used when replacing the screw of the injection device, and it is not necessary for large injection molding machines. There is no need for the difficult work of rotating the injection device and replacing screws.
This can be done as r%7.

(Examples) Hereinafter, in order to clarify the present invention more specifically, examples of the present invention will be described in detail based on the drawings.

First, in Figures 1 and 2, 2 is the base,
A fixed platen 4 is erected in a fixed position on this base 2'', and an end plate 6 is erected and fixed to face the fixed platen 4 at a predetermined distance 1 distance from the fixed platen 4. There is. Four tie bars 8 are provided between the fixed platen 4 and the end plate 6 to connect the corresponding corners. Furthermore, a movable platen 10 is provided, into which the four tie bars 8 are pushed through and guided along the tie bars 8.

A side cylinder 12 as a mold opening/closing means is installed between the movable platen 10 and the fixed platen 4, and the movable platen 10 approaches and moves away from the fixed platen 4 by its expansion and contraction. It's like being forced to do something. A large shoe 14 is provided at the bottom of the movable platen 10, and the shoe 14 slides on a guide rail 16 provided on the base 2 in the left-right direction in the figure. Furthermore, each movable platen 10 is provided with a locking device 18 that engages with a tie bar 8 passing through the movable platen 10 to prevent movement of the movable platen 10.

This locking device 18 is, for example, a half-shaped split nut 2.
0 are combined and opened and closed by the lock cylinder 22 to engage the engagement groove 24 provided at a predetermined position of the tie bar 8, thereby fixing the movable platen 10 immovably.

On the other hand, a pressure boosting cylinder 26 is integrally provided in the stationary platen 4 in the form of a built-in central portion thereof, and the pressure boosting cylinder 26 is supplied with pressure oil supplied through the pressure oil port 28. The fitted pressure booster ram 30 and the pressure booster plate 32 attached to the pressure booster ram 30 and guided by four wooden tie bars 8 are moved forward, and thus the pressure booster plate 32 is moved forward, and is thus provided between the movable platen 10. A pressure increase action (mold clamping force or pressing force) is applied to a predetermined mold 34. Further, as is well known, the metal thickness 134 is made up of a fixed mold 36 and a movable mold 38, and the fixed mold 36 is fixed to the pressure intensifier plate 32 as indicated by -. The movable mold 38 is fixed to the movable platen 10, and when the fixed mold 36 and the movable mold 38 are closed, a product cavity ( (not shown) is formed.

Note that an ejector cylinder 4 is provided inside the pressure booster ram 30.
By operating the ejector cylinder 40, the ejector pin provided through the pressure intensifier plate 32 is ejected, and the molded product formed in the product cavity in the mold 34 is removed from the mold after the mold is opened. 34 (Fixed mold 3
6) so that it can be made to fall. Also, the second
In the figure, reference numeral 44 denotes a pressure intensifier plate stopper that prevents the pressure intensifier plate 32 from moving toward the movable platen 10 when the mold 34 is opened.

Further, behind the movable platen 10, that is, on the right side of the movable platen 10 in the figure, there are two support plates 46. ．． 1
An injection device 50 held at 8 is disposed. Therefore, this injection device 50 has support plate 4.6.48.
By moving along the tie bar 8, the tie bar 8 can be moved toward or away from the fixed platen 4, in other words, in the arrangement direction of the tie bar 8. Here, since the movable platen 10 and the support plate 46 are connected by the shift cylinder 52, they are both moved in the same direction as the movable platen 10 is moved to open and close the mold by the side cylinder 12. becomes.

Furthermore, as is well known, the injection device 50 includes a heating cylinder 54, an injection cylinder 56, a decelerator 58, a motor 60
, a hopper 62, etc., a predetermined resin material supplied from the popper 62 is plasticized in the heating cylinder 54 under the compression action of the screw, and is formed into the gold Z mold 34 from the nozzle part 64 at the tip thereof. The product can be injected into a predetermined product cavity.

For such an injection operation into the product cavity in the mold 34, the injection device 50 penetrates the movable platen 10, and the nozzle portion 64 of the injection device 50 penetrates the movable mold 38 of the mold 34, more specifically, It is adapted to be attached to a sprue bushing for guiding the resin material into the mold. Note that a movable plate 10 is provided at the bottom of the support plate 48 that supports the injection device 50.
Similarly, a shoe 66 is provided, and the guide rail 1
6" can be slid.

Therefore, the operation of the injection molding machine having such a structure is as follows.

First, when the movable platen 10 is moved to the left by the side cylinder 12 and the mold 34 is closed,
The injection device 50 is moved in the same direction as the movable platen 10 while always touching the movable platen 10 and the mold 34. Next, in the closed state of the mold, the lock cylinder 22 of the locking device 18 is activated to open the splitters 1 to 1.
20 into the engagement groove 24 of the tie bar 8, the movable platen 10 and the tie bar 8 are locked. Then, a pressure oil boat 28 is connected to a pressure increase cylinder 26 built in the fixed platen 4.
Pressure oil is sent to the nozzle of the injection device 50 to tighten the mold 34 between the movable platen 10 and the pressure increase plate 32 by sending pressure oil to the shift cylinder 52 to increase the pressure. A sufficient amount of gust is generated in the portion 64. FIG. 1 shows the pressurizing and molding position. In this state, a predetermined plasticized resin material is injected from the injection device 50 into the product cavity within the mold 34.

When the injection operation is completed and the resin material in the product cavity of the mold 34 is cooled and solidified, the locking device 18 is opened and unlocked, and the side cylinder 12 opens the mold, allowing the mold to move. Board 10
is moved to the right in the figure, but
At this time, from the state where the movable plate 10 and the support plate 46 are connected by the shift cylinder 52, the injection device 50 is simultaneously moved to the right by being pushed by the movable plate 10 aJ+
(a)・u is shown. Then, in this mold open state, the molded product formed in the mold 34 is taken out, and the injection molding operation is repeated in the same manner as in the above. In addition, FIG. 2 shows a state in which the mold is opened and the molded product is taken out as described in "2".

As described above, in the injection molding machine having such a structure, the injection device 50 is provided on the side of the movable platen 10 and is movable together with the movable platen 10, and the movable platen 10 is placed at an appropriate position. Since the tie bar 8 is locked by the locking device 18 and fixed immovably, the pressure increasing action by the pressure increasing cylinder 26 from the side of the fixed platen 4 is effective against the mold 34. As a result, the number of parts can be significantly reduced compared to conventional mold clamping devices, and a mold clamping mechanism for large injection molding machines with a simple structure can be realized. It is.

Further, the mold clamping stroke by the pressure boosting ram 30 operated by the pressure boosting cylinder 26 is always on the order of several cranes, and therefore the amount of pressure oil required for pressure increase can be extremely reduced. Furthermore, the mold opening/closing side cylinder 12 is used only for moving the movable platen 10 and does not apply a clamping action, so it is made smaller.
The amount of pressurized oil for its operation can be reduced (in addition,
Instead of such a side cylinder, it is also possible to use other suitable moving means as the mold opening/closing means.

Moreover, in an injection molding machine having the structure as in the above example, there is no large device such as a mold clamping cylinder behind the fixed platen 4, and therefore the installation space can be shortened accordingly. Furthermore, even if the thickness of the mold 34 changes, the mold clamping stroke by the pressure boosting ram 30 of the pressure boosting cylinder 26 can be sufficiently achieved by simply changing the locking position of the locking device 18 of the movable platen 10. This eliminates the need for conventional die spacers, ram spacers, etc., and allows freedom in design such as delight and minimum mold thickness. In addition,
Even when replacing the screw of the injection device 50, the space of the Delight can be used, and there is no need to perform the work with the injection device 50 rotated as in the conventional case.

In the injection molding machine of this embodiment, the pressure boosting cylinder 26 is built into the fixed platen 4, and the mold clamping action of the pressure boosting ram 30 is applied to the mold 34 via the pressure boosting plate 32. Since it is made to act effectively on the central part of the fixed mold 36, there is also the advantage that there is little loss of force.

In addition, in the injection molding machine of the above example, a long Ihaa 8 is used in which the mold clamping side part that guides the movable platen 10 and the injection side part that guides the injection device 50 are integrated. It is also possible to adopt a structure in which the mold is divided into the mold clamping side and the injection side, and furthermore, as shown in FIGS. 3 and 4, the injection device M50 can be moved separately from the movable platen 10. It is also possible to adopt a structure in which tie bars 8 are provided only on the mold clamping side.

That is, in the other embodiments shown in FIGS. 3 and 4, the injection device 50 is supported by a moving table 70 guided by a guide 68 provided on the base 2, and the shift cylinder 52 expands and contracts. Depending on the operation, it can move forward or backward, that is, move forward toward the fixed platen 4 or move back from there.

Therefore, in the injection molding machine having the structure of this embodiment, during its operation, the injection device 50 is moved forward and backward at the same time as the movable platen 1o so as not to interfere with the movement of the movable platen 10.
Alternatively, when closing the mold, the movable platen 10 is moved and then the injection device 50 is moved to perform the nosulting operation, and when the mold is opened, the injection device 50 is first moved back and then the movable platen 10 is not moved. That will happen.

Although the embodiments of the present invention have been described in detail above, the present invention is not to be construed as being limited to such embodiments, and the present invention shall not be interpreted as being limited to such embodiments. may be implemented in forms with various changes, modifications, improvements, etc., and the present invention includes such embodiments.
There is no Uma-C.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front explanatory view showing an example of the injection molding machine according to the present invention in the pressure increasing and molding position, and Fig. 2 shows the injection molding machine in the mold opening and molded product removal position. It is a front explanatory view. FIG. 3 is a diagram corresponding to FIG. 2 showing another embodiment of the present invention, and FIG.
−■ It is a cross-sectional explanatory diagram. 4: Fixed plate 8: Tihar 10: Movable plate 12: Side cylinder 18:
Rosoku device 26: Pressure booster 30: Pressure booster ram
32: Pressure increase plate 34: Mold 50: Injection device 52: Shift cylinder 64: Nozzle part 70: Moving table

Claims (5)

[Claims] (1) A predetermined mold is disposed between a fixed platen and a movable platen, and a mold opening/closing means for moving the movable platen is provided to open and close the mold, while the mold is opened and closed by the mold opening/closing means. A locking mechanism is provided to fix the movable platen immovably in the closed state, and a pressure booster cylinder is further provided on the fixed platen side, and when the movable platen is fixed by the locking mechanism, a pressure increaser is provided from the fixed platen side. While the pressure increasing cylinder is used to clamp the mold, an injection device is provided behind the movable platen for injecting a predetermined plasticized resin material into a product cavity formed in the mold. An injection molding machine, characterized in that the injection molding machine is movably installed so that a nozzle of the injection device penetrates the movable platen and comes into contact with the mold, thereby injecting the resin material. (2) The injection molding machine according to claim 1, wherein the mold opening/closing means is constituted by a side cylinder provided between the fixed platen and the movable platen. (3) The pressure booster cylinder is built in the center of the fixed plate, and one side of the mold is attached to the pressure booster ram of the pressure booster cylinder via a predetermined pressure booster plate, so that the mold An injection molding machine according to claim 1 or 2, wherein a pressure increasing action is applied to the central portion. (4) The injection device according to any one of claims 1 to 3, wherein the movable platen and the injection device are connected, and the injection device is moved in the same direction as the movable platen moves to open and close the mold. Molding machine. (5) According to any one of claims 1 to 3, the injection device is moved by a moving means separate from the mold opening/closing means, and is movable toward and away from the movable platen. injection molding machine.