JPH084271Y2 - Injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an injection molding machine.

(Prior Art) Conventionally, a molding material that has been heated and fluidized in a heating cylinder is injected into a mold by high pressure, cooled and solidified or hardened therein, and then the mold is opened to take out a molded product. As such an injection molding machine, one shown in FIG. 3 is provided.

That is, a mold clamping device 2 and an injection device 3 are installed on a machine base 1, the mold clamping device 2 includes a fixed platen 4 and a movable platen 5, and a mold clamping cylinder 6 is provided along a tie bar 7. When the movable platen 5 is reciprocated, the fixed mold 8 and the movable mold 9 come into contact with and separate from each other.

Further, the injection device 3 is reciprocally provided with a nozzle 11 for heating and melting the molding material in the hopper 10, that is, resin, and injecting the molten material, and the molten resin is injected from the nozzle 11 into the mold recesses 8a, 9a. To be done. On the other hand, the molded product is discharged from the outlet 12 to the machine base 1.
It is designed to fall down and be discharged.

In the injection molding machine as described above, the movable mold 9 reciprocates every time molding is performed, and comes in contact with and separates from the fixed mold 8 that opposes the movable mold 9. Therefore, a mold clamping cylinder 6 is provided in order to reciprocate the movable mold 9 and to increase the force of pressing against the fixed mold 8, that is, the mold clamping force.

When the movable platen 5 is moved along the tie bar 7 by operating the mold clamping cylinder 6 to bring the movable mold 9 into contact with the fixed mold 8, the end faces of both molds 8 and 9 are accurately If they do not match, the molten resin injected from the nozzle 11 of the injection device 3 into the mold recesses 8a and 9a may leak out through the gap between the molds 8 and 9. Therefore, the movable platen 5 and the fixed platen 4 are arranged in parallel with each other so that a gap is not formed between the end faces of the molds 8 and 9.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional injection molding machine, when the injection molding is performed in a state where the mold temperature exceeds 80 ° C., it is provided to maintain the mold at a predetermined temperature or higher. The platen itself becomes high temperature due to the heat transmitted through the mold temperature controller or through the resin. At that time, the platen is deformed by thermal expansion, and the parallelism between the platens cannot be maintained, which causes galling of the mold and uneven thickness of the molded product.

Therefore, it is necessary to raise the temperature at the mold temperature that is actually used, ensure the accuracy by adjusting the parallelism when the platen temperature reaches a steady state, and readjust when the mold changes.

The present invention solves the problems of the conventional injection molding machine described above, and when the temperature of the mold is high, the temperature of the platen is controlled by the heat transmitted through the mold temperature controller or through the resin. An object of the present invention is to provide an injection molding machine capable of continuing operation with the initial setting without rising and being unable to maintain parallelism between platens.

(Means for Solving the Problems) Therefore, in the injection molding machine of the present invention, the fixed platen, the movable platen facing the fixed platen so as to be contactable and separable, and the movable platen are slidable. It has a tie bar that supports it freely.

The fixed platen and the movable platen include a cooling medium flow path formed by being separated from the fixed mold and the movable mold.

(Operation) According to the present invention, as described above, in the injection molding machine, the fixed platen, the movable platen disposed so as to face the fixed platen so as to be able to come in and out of contact with the fixed platen, and the movable platen are slidable. And a supporting tie bar.

The fixed platen and the movable platen include a cooling medium flow path formed by being separated from the fixed mold and the movable mold.

In this case, the cooling medium does not flow in the fixed mold and the movable mold but flows in the flow paths in the fixed platen and the movable platen, and suppresses the temperature rise of the fixed platen and the movable platen.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a view showing a fixed platen of an injection molding machine of the present invention, FIG. 1 (A) is a side view thereof, and FIG. 1 (B) is a front view thereof.

In the figure, 21 is a fixed platen, and holes 22 through which tie bars penetrate are formed at four corners of the fixed platen 21. A hole 23 is formed in the center of the stationary platen 21 for penetrating the nozzle of the injection device and contacting the sprue of the mold. The hole 23 is a tapered portion formed on the injection device side.
23a and a small diameter portion 23b following it.

The fixed platen 21 has legs 24 at the bottom.
Is fixed to the base of the injection molding machine via.

In the fixed platen 21 having the above structure, a fixed mold is arranged on the end face 26 side. The fixed mold comes into contact with the movable mold on the movable platen side, and the resin is injected from the nozzle into the cavity formed between them. Since the resin is heated by a heating cylinder and injected in a molten state, the temperature of the resin is considerably high, and the heat of the resin is fixed by a fixed platen through a fixed mold.
Delivered to 21. Usually, a mold temperature controller is often used so that the resin temperature does not suddenly change when the resin is injected into the cavity. However, the heat generated by the mold temperature controller is similarly fixed platen. Delivered to 21.

The heat raises the temperature of the stationary platen 21 and causes thermal expansion. Therefore, in order to prevent this temperature rise, a flow path 25 for flowing a cooling medium, for example, cooling water, is formed inside the fixed platen 21. The flow path 25 extends through the fixed platen 21 so as to surround the hole 23.

2 is a view showing a movable platen of the injection molding machine of the present invention, FIG. 2 (A) is a side view thereof, and FIG. 2 (B) is a front view thereof.

In the figure, 31 is a movable platen, and holes 32 through which tie bars penetrate are formed at four corners of the fixed platen 31. At the center of the movable platen 31, there is formed a hole 33 through which an ejector rod for taking out a molded product in the mold penetrates.

The movable platen 31 has a flange portion 34 for connecting the toggle mechanism to the mold clamping device side.

In the movable platen 31 having the above structure, the movable mold is arranged on the end surface 36 side. The movable mold comes into contact with the fixed mold on the fixed platen side, and the resin is injected into the cavity formed between the movable mold and the fixed platen.

Therefore, similar to the fixed platen 21 (FIG. 1), the heat of the resin and the heat generated by the mold temperature controller are transmitted to the movable platen 31 via the movable mold.

The heat raises the temperature of the movable platen 31 and causes thermal expansion. Therefore, in order to prevent this temperature rise, like the fixed platen 21, a flow path 35 for flowing a cooling medium, for example, cooling water, is formed inside the movable platen 31. The flow path 35 is movable platen so as to surround the hole 33.
Extends through 31.

As described above, the fixed platen 21 and the movable platen 31
By forming the flow passages 25 and 35 through the flow passages 25 and 35 and flowing the cooling water into the flow passages 25 and 35, the platen itself is kept at a low temperature even if the mold temperature is high to suppress the thermal expansion. I try to keep the parallelism between 31.

If there is no means to cool the platen, the mold temperature will be 120
When molded at 20 ° C for 20 seconds, the temperature of both platens 21 and 31 reaches 70 ° C during steady operation. If the parallelism between both platens at room temperature is 20 μm, it will be 100 during normal operation.
reaches μm.

On the other hand, when water at 20 ° C. is passed through both platens 21 and 31, the platen temperature during steady operation is 40 ° C., and the parallelism is maintained at about 30 μm.

It should be noted that the present invention is not limited to the above embodiments, and various modifications can be made based on the spirit of the present invention, and these modifications are not excluded from the scope of the present invention.

(Effects of the Invention) As described above, according to the present invention, in the injection molding machine, the fixed platen, the movable platen facing the fixed platen so as to be able to come in contact with and separated from the fixed platen, and the movable platen are provided. And a tie bar slidably supported.

The fixed platen and the movable platen include a cooling medium flow path formed by being separated from the fixed mold and the movable mold.

In this case, the cooling medium does not flow in the fixed mold and the movable mold but flows in the flow paths in the fixed platen and the movable platen.

Therefore, even if the temperature of the fixed mold and the movable mold rises, the temperature rises of the fixed platen and the movable platen can be sufficiently suppressed, so that the fixed platen and the movable platen may be deformed by thermal expansion. Disappear.

Further, since the parallelism between the fixed platen and the movable platen can be maintained, it is possible to prevent galling of the fixed mold and the movable mold, unevenness of the thickness of the molded product, and the like.

Further, it is not necessary to adjust the parallelism between the fixed platen and the movable platen when the temperature of the fixed platen and the movable platen reaches a steady state by raising the temperature at the mold temperature actually used.

[Brief description of drawings]

FIG. 1 is a view showing a fixed platen of an injection molding machine of the present invention,
1 (A) is the same side view, FIG. 1 (B) is the same front view, FIG. 2 is a view showing the movable platen of the injection molding machine of the present invention, and FIG. 2 (A) is the same side view. FIG. 2 (B) is the same front view and FIG.
FIG. 1 shows a conventional injection molding machine. 21 …… Fixed platen, 25,35 …… Flow path, 31 …… Movable platen.

Claims (1)

[Scope of utility model registration request] 1. A fixed platen; (b) a movable platen disposed so as to come in contact with and separated from the fixed platen; and (c) a tie bar slidably supporting the movable platen. In addition to (d) the fixed platen and the movable platen, the injection molding machine is characterized in that the fixed platen and the movable platen are provided with a flow path of a cooling medium formed separately from the fixed mold and the movable mold.