JPH0441214A - Mold device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention relates to a mold device used for injection molding of plastics, etc., and particularly relates to a mold device that can reduce mold clamping force. .

(Prior art) Conventionally, in methods for molding materials with relatively low melting points, such as plastic injection molding and zinc alloy die casting, two molds are clamped in advance, and a Molded products are obtained by injecting molding materials.

FIG. 3 is a sectional view of a conventional mold device used for plastic injection molding.

In FIG. 3, reference numeral 1 indicates an injection mold, and this injection mold 1 has a first mold (hereinafter referred to as a male mold) 2 and a second mold (hereinafter referred to as a female mold). 3, and a space 4 (hereinafter referred to as a cavity) is created by combining the respective facing surfaces 2a and 3a. A movable mold plate 5. is provided on the opposite surface of the male mold 2 and female mold 3 from the facing surfaces 2a and 3a, respectively. A fixed mold plate 6 is attached. A mold clamping device such as a hydraulic mold clamping cylinder (not shown) is attached to the movable mold plate 5, and it is possible to press the male mold 2 against the female mold 3 in the mold clamping direction (direction A in the figure). It is now possible to do so. A runner 7 is formed in the female mold 3 so as to communicate with the cavity 4. One end of this runner 7 becomes a hot water lower a connected to the cavity 4, and the other end of the runner 7 is connected to a nozzle 8 of a plastic injection molding machine.

As a result, the molding material (high-temperature, high-pressure plastic) passes through the nozzle 8, passes through the runner 7, and enters the cavity 4 from the hot water lower a.

When molding plastic using such a conventional mold device, the movable mold plate 5 is moved in the mold clamping direction, and the male mold 2 and the female mold 3 are brought together to clamp the mold 1. Thereafter, the cavity 4 is filled with the high-temperature, high-pressure plastic by injecting the high-temperature, high-pressure plastic from the hot water lower a through the nozzle 8 and the runner 7 using a plastic injection molding machine. After that, the mold 1 is cooled by a water cooling device (not shown).
At the same time, the pressure of the high-temperature, high-pressure plastic from the plastic injection molding machine is reduced, causing hot water to run out near the other end of the runner 7. Thereafter, by moving the movable mold plate 5 in the opposite direction to the mold clamping direction, the mold 1 is opened, the male mold 2 and the female mold 3 are separated, and the molded product is taken out from the female mold 3.

By the way, in the molded product, an unfilled part remains due to the air inside the cavity 4. In order to make this unfilled part sufficiently small, the high temperature and high pressure plastic from the plastic injection molding machine must be under as high a pressure as possible. No, there,
In such a mold apparatus, the pressure during injection of high-temperature, high-pressure plastic is set to about 500 ksr/-. With such settings, for example, radius 10Q11
When molding a plate of about 150 mm, a mold clamping force of 157 mm or more is required.

For this reason, a large mold clamping device was required.

(Problems to be Solved by the Invention) As explained above, in conventional mold devices, a very strong mold clamping force is required to clamp the mold when molding material is injected, and the mold clamping force that generates this mold clamping force is needed a large one.

The object of the present invention is to provide a mold device that can eliminate the above-mentioned problems and reduce the mold clamping force of a mold clamper.

[Refinement of the Invention] (Means for Solving the Problems) The present invention provides a mold consisting of a first mold and a second mold that create a space by bringing their respective mating surfaces together; It is characterized by comprising an electromagnet embedded in at least one of the mating surfaces of the mold and applying an attractive force to the opposing mating surfaces.

(Function) According to such a configuration, when the first and second molds are clamped, a clamping force is applied between the first and second molds by the attraction force of the electromagnet, so that the molds are clamped together. The mold clamping force of the mold clamper installed outside the mold can be reduced.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a mold apparatus according to the present invention. The configuration other than that shown in FIG. 1 is the same as that of the conventional example shown in FIG. 3, and the same components as in FIG. 3 are given the same reference numerals.

In Fig. 1, the difference from the conventional example in Fig. 3 is that the mold 1
Holes 11.12 are formed above and below the cavity 4 on the mating surface 2a of the male mold 2, respectively, and electromagnets 13.14 are embedded in the holes 11.12. The attracting surfaces of the electromagnets 13 and 14 are the matching surfaces 2a
They are flush with each other, so that when the male die 2 and the female die 3 are crimped together, no gap is created between the mating surfaces 2a and 3a. Further, although not shown, the coils of the electromagnets 13 and 14 are led out from the male mold 2 and connected to a DC power supply circuit not shown.

The operation of the mold apparatus shown in FIG. 1 will be explained with reference to FIG. 2.

Fig. 2 (a) shows the state in which the mold device is open, Fig. 2 (b) shows the state in which the mold device is closed, and Fig. 2 (c) shows the state in which the molding material is injected into the mold device; Figure (d) shows the molded product removed from the mold device.

When molding plastic using a mold device, first, as shown in FIG. 2(a), the movable mold plate 5 of the mold device in an open state is moved by driving a mold clamper (not shown). Move it in the mold clamping direction (direction into the figure) and
), match the male mold 2 and female mold 3. moreover,
By turning on the DC power supply circuit and applying current to the coils of the electromagnets 13 and 14 to attract the mating surfaces 3a to the electromagnets 13 and 14, the male mold 2 and the female mold 3 are crimped together, and the mold is made]
After that, as shown in Fig. 2 (C),
A plastic injection molding machine injects the high-temperature, high-pressure plastic 15 into the cavity 4 by injecting the high-temperature, high-pressure plastic 15 from the hot water lower a through the nozzle 8 and the runner 7.
Fill 5. After that, the mold 1 is cooled by a water cooling device (not shown) to harden the high-temperature, high-pressure plastic 15, and the pressure of the high-temperature, high-pressure plastic 15 from the plastic injection molding machine is reduced, so that the mold 1 is cooled near the other end of the runner 7. cause a break. After that, as shown in FIG. 2(d), the DC power supply circuit is turned off, no current flows through the coils of the electromagnets 13 and 14, and the adhesion of the mating surfaces 3a is released, and the movable mold plate 5 is A molded product in which the mold 1 is opened and the male mold 2 and the female mold 3 are separated by moving in the direction opposite to the mold clamping direction (direction B in the figure), and the high temperature and high pressure plastic 15 is solidified from the female mold 3. Take out 16.

According to the mold apparatus of this embodiment, in addition to the mold clamper, mold clamping force is applied to the male mold 2 by the attraction of the electromagnets 13 and 14, so it is possible to reduce the mold clamping force of the mold clamper. , the mold clamping device can be made smaller.

In addition, in the mold apparatus of this embodiment, the electromagnets 13° and 14
is provided on the male mold 2, but may be provided on the female mold 3.

In addition, in the mold apparatus shown in FIG. 1, a sensor for detecting pressure is provided in the cavity 4 or the runner 7, and when the high temperature and high pressure plastic 15 is injected, the DC power circuit is turned on and the electromagnet 13. The mating surface 3a may be attracted.

Furthermore, in the mold apparatus shown in FIG. 1, a sensor is provided to detect the pressure applied to the mating surface 2a or the mating surface 3a, and the pressure detected by the sensor exceeds a predetermined pressure due to the mold clamping force of the mold clamping device. When the pressure is detected by the sensor, the DC power circuit is turned on, and when the pressure detected by the sensor falls below the specified pressure, the DC power circuit is turned off. It is possible to perform off control and drive the electromagnets 13 and 14.

[Effects of the Invention] As explained above, according to the present invention, in addition to the mold clamper attached to the outside of the mold, the first
Since the mold clamping force is applied to the second mold, the mold clamping force of the mold clamper can be reduced, and the mold clamper can be made smaller.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the mold device according to the present invention, FIG. 2 is an explanatory diagram illustrating the operation of the mold device shown in FIG. 1,
FIG. 3 is a sectional view of a conventional mold device. 1...Mold, 2...Male mold, 3...Female mold, 2a, 3
a...Mating surface, 4...Cavity, 13, 14
···electromagnet. Agent Patent Attorney Norihiro Chika Hiroki Uji 1 Mold Diagram 1/1 Diagram 3

Claims (1)

[Scope of Claims] A mold consisting of first and second molds whose respective mating surfaces are brought together to create a space; embedded in the mating surface of at least one of the first and second molds, A mold device characterized by comprising an electromagnet that applies an attractive force to opposing mating surfaces.