JPS608929B2 - How to release molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold release method for easily ejecting a molded product from a mold in an injection molding machine or the like.

For example, it is well known that a mechanical product ejection device, a hydraulic product ejection device, etc. are used to eject a molded product from a mold in an injection molding machine. The product ejection force in these devices is determined by the following: [a] shape of the molded product and contact area with the mold, o) surface condition of the surface where the molded product and the mold contact,
This is determined by various factors such as the draft angle, the type of die resin, and the molding conditions, but if this product ejection force is large, the product ejection device needs to have considerable rigidity, so the device must be large. On the other hand, it is necessary to upgrade the mechanical elements that make up the equipment (material, quality, etc.), and because a large force is applied to the molded product during discharge, problems such as deformation and damage to the molded product may occur. arise. In this way, the product ejection force has an extremely large effect not only on the related equipment but also on the contents of the molded product, and in order to keep this product ejection force below a predetermined value, it may be necessary to change the properties and form of the molded product that are originally intended. If this change is impossible, molding becomes impossible, which poses a very serious problem. In order to solve this problem, the present invention uses a vibrator attached to a molding die to apply vibrations to the mold during or before the start of the releasing operation to release the molded product from the mold. To provide a method for releasing a molded article, which allows the molded article to be ejected with a smaller force.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be explained in detail below with reference to the drawings.

1 is a fixed plate, 2 is a movable plate movably provided along the tie bar 3 by a cylinder (not shown), etc., and 4 and 5 are molding molds (hereinafter referred to as 4) attached to the fixed plate 1 and the movable plate 2, respectively. 5 is called a cavity mold, and 5 is called a core mold).

The core mold 5 has a core portion 5a that forms a contact surface with the molded product of the core mold 5 and is slidably attached to the core mold 5. 6 is a vibrator attached to the core mold 5.

For molding, first move the movable platen 2 from the left side to the position shown in the figure, and move the core mold 5 into the cavity mold 4.
Both molds are tightened with the necessary mold clamping force, and then the gate part 4a of the cavity mold 4 is tightened using an injection device (not shown).
The molded article 7 is formed by filling the molded article 7 with resin, but the method up to this filling is no different from the conventional method.

In the present invention, after the filling, the vibrator 6
This applies vibration to the core portion 5a, the core mold 5, and furthermore the cavity mold 4.

It has been found that by applying this vibration, the adhesion force generated between the core mold 5 and the molded product 7 is reduced, making mold release very easy. In other words, according to experiments, when molding a cup, applying vibration of 20KHZ with an amplitude of 20F for 2 to 3 seconds was found to be sufficiently effective, and it was possible to easily take out a deep cup that was difficult to release from the mold. It is. Note that the vibration to be applied may be ultrasonic vibration or something similar thereto. Further, the period of time for applying vibration to the mold may be after the mold is opened, and in that case, it may be before the start of the mold release operation or during the mold release operation.

As described above, according to the present invention, the mold can be released extremely easily and the product can be ejected with a very small force, which makes it possible to downsize and simplify the product ejection device, and to remove the molded product. Deformation, damage, etc. are also significantly reduced, and the degree of freedom in determining the shape of the molded product can be greatly increased.

The present invention is particularly effective in releasing the following molded products. '1} Deep molded products, ■ Molded products subjected to texture processing, [31 Precision molded products, ■ Molded products with a draft angle Q of 0.5 degrees or less, '51 Molded products that require a mold release agent. , If this mold release agent may have an adverse effect on the molded product, ``6} Hard and brittle molded products such as PS, (7) Cracks may occur in the molded product due to the action of local discharge stress. For example, in some cases.

[Brief explanation of the drawing]

The figure is a sectional view showing one embodiment of the present invention. 1...Fixed plate, 2...Moveable plate, 4,5
...Molding mold, 6... Vibrator, 7.
…··Molding.

Claims (1)

[Claims] 1 A cavity mold installed on a fixed platen, a core mold installed on a movable plate that moves forward and backward with respect to the cavity mold and engages with and disengages from the cavity mold, and a molded product of the core mold. A molding die consisting of a core part that forms a contact surface and is slidably attached to the core mold, and a vibrator attached to the core part, is subjected to mold release operation or mold release by the vibrator. A method for releasing a molded article, which comprises releasing the molded article from the molding die by applying vibration before starting the operation.