JPS5923697B2 - Injection molding equipment with magnetic field - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection molding apparatus having a magnetic field coil for molding plastic magnets.

When forming plastic magnets by injection molding, for example, a synthetic resin material mixed with powder of a magnetic material (barium ferrite, etc.) is injected into the gear via of a mold, and this is then applied to the outside of the mold. There are some that perform anisotropic shaping using the magnetic field of a fixed magnetic field coil.
In this case, in order to make the molded product sufficiently anisotropic, it is necessary to use a large magnetic field coil that can generate a strong magnetic field, and it is also necessary to use this magnetic field coil to generate a magnetic field around the outer periphery of the mold. . However, if the magnetic field coil is fixedly installed, the magnetic field coil becomes an obstacle when opening a mold to take out a molded product. Therefore, it may be possible to lengthen the mold opening stroke to make it easier to take out the molded product, but this would still make it difficult to attach and remove the mold from the machine. There are problems in that it is difficult to confirm if there are any remaining. The present invention has been made in view of the above problems, and is provided with a magnetic field coil that surrounds the outer periphery of an injection mold and is movable in the mold opening/closing direction. An object of the present invention is to provide an injection molding apparatus having a magnetic field that allows easy removal of a molded product by moving the molded product to a position where it does not get in the way.

Next, the configuration of an embodiment of the present invention will be explained with reference to the accompanying drawings.

Four tie bars 4 are installed between a fixed die plate 2 and a tail stock 3 supported on an abutment 1, and one end of the lower pair of diepers 4 is extended outward from the fixed die plate 2. The end portion is fixed to a projecting body 5 projecting from the support base 1.

Furthermore, a movable die plate 6 that moves forward and backward toward the fixed die plate 2 is slidably installed on the tie bar 4, and the fixed die plate 2 and the movable die plate 6 each have fixed molds □ as molds. and a movable mold 8 are provided protrudingly facing each other. Further, a magnetic field coil 9 formed in an annular shape is disposed at a position surrounding the outer periphery of the fixed mold T and the movable mold 8 when the molds are closed, and this magnetic field coil 9 is connected to the support base 1.
It is supported so as to be slidable in the axial direction, that is, in the opening/closing direction of the movable mold 8 via a guide/base 10 on the top, and a pair of piston rods 11 are connected to one end. It is connected to a piston 13 of a fixed cylinder 12 for moving the coil. Furthermore, a toggle link 17 is attached to the tip of the piston rod 16 connected to the piston 15 of the mold clamping cylinder 14 attached to the support base 1.
One end of this toggle link 17 is pivoted to an arm piece 18 extending from the tail stock 3, and the other end is connected to the movable die plate 6 via a connecting rod 19.
It is pivoted to an arm piece 20 that protrudes from. Furthermore, fluid passages 22 and 23 that are switched between a fluid sending side and a fluid returning side are communicated with the cylinder 12 for moving the coil via a solenoid valve 21, and branch passages branch from the middle of each fluid passage 22 and 23. 24 and 25 are sequence valves 262 in the middle
The mold clamping cylinder 14 is connected to the mold clamping cylinder 14 via the cylinder 7.

In addition, in the drawing, 28 is a safety door, and 29 is a door guide. Further, 30 is an injection unit supported on the base 1,
It is composed of a hopper 31, a heating cylinder 32, an injection nozzle 33, an oil motor 34 for one revolution of the screw, an injection cylinder 35, and a hydraulic valve 36. Next, the operation of the above configuration will be explained. When the mold is opened, the solenoid valve 21 is activated in Fig. 3.
The A position communicates with the fluid passages 22 and 23, and fluid is sent from the pump P to the I chamber of the cylinder 12 for moving the coil, moving the piston 13 in the direction of the solid line arrow, and moving the magnetic field coil connected to the piston rod 11. 9 is moved back from the position of the molds 7 and 8 when the molds are clamped.

At the same time, the increase in pressure in the I chamber of the cylinder 12 for coil movement causes the sequence valve 26 of the branch passage 24 to conduct, fluid enters the I chamber of the mold clamping cylinder 14, and the piston 15 advances in the direction of the solid line arrow, causing the toggle to move. The movable die plate 6 is moved backward together with the movable die 8 via the link 17, and the die is opened. Therefore, the retraction operation of the magnetic field coil 9 and the mold opening operation are performed in synchronization. In addition, at this time, the cylinders 12 and 14
The fluid in each chamber is divided into a fluid passage 23 and a branch ? It is returned to tank T through check valve 5. next,
When the mold is closed, the B position of the solenoid valve 21 in FIG. 3 is communicated with the fluid passages 22 and 23.

In this case, fluid is pressurized into the chamber of the cylinder 12 for moving the coil, and the piston rod 11 is advanced in the direction of the dotted arrow, thereby advancing the magnetic field coil 9 to the mold clamping position of the molds 7 and 8. At the same time, the pressure in the chamber of the cylinder 12 rises, causing the branch passage 2 to
The sequence valve 27 of No. 5 is turned on, allowing the fluid to flow into the chamber of the mold clamping cylinder 14, and the fluid in the I chamber of the cylinders 12 and 14 is returned to the tank T through the check valve of the fluid passage 22 and the branch passage 24. . Further, the piston 15 retreats in the direction of the dotted line arrow, and the movable die plate 6 and the movable mold 8 advance through the toggle link 17 connected thereto, and the molds are clamped. Next, the heating cylinder 32 of the injection unit 30 advances and injects a synthetic resin material mixed with powder of a magnetic material such as barium ferrite into the cavity surrounded by the molds 7 and 8. Since the outer peripheries of the molds 7 and 8 are surrounded by a magnetic field coil 9 and a magnetic field is generated, the powder of the magnetic material in the molds 7 and 8 is arranged in the direction of the magnetic field and is anisotropic. In the above embodiment, the opening and closing of the molds 7 and 8 and the movement of the magnetic field coil 9 were performed in synchronization, but the movement of the magnetic field coil 9 was performed in synchronization with the movement of the molds 7 and 8.
8 may be opened and closed manually. According to the present invention, an injection mold that can be opened and closed is provided, and a magnetic field coil for generating a magnetic field that surrounds the outer periphery of the mold is provided so as to be movable in the opening and closing direction of the mold independently of the mold. Therefore, when the mold is clamped, by surrounding it with a magnetic field coil, a magnetic field is applied to the molded product containing the magnetic material powder injected into the mold cavity, and the magnetic material is sufficiently anisotropic. In addition, when the mold is opened, the magnetic field coil can be easily moved to a position where it does not interfere with the ejecting operation of the molded product, and the molded product can be easily taken out from the mold. Inspection and confirmation of residue inside the mold can be easily performed, and the magnetic field coil
Since it is installed separately from the mold and is movable with respect to the mold, it is economical because there is no need to replace the magnetic field coil even if the mold is replaced.Moreover, the magnetic field coil receives heat directly from the mold. It is possible to provide an injection molding apparatus that can be used permanently without being affected by physical effects, is easy to handle, and can mold molded products with high precision.

[Brief explanation of the drawing]

FIG. 1 is a front view of an injection molding apparatus showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line A--A of the same, and FIG. 3 is an explanatory view of the oral function. 7, 8... Mold, 9... Magnetic field coil,
33...Injection nozzle.

Claims (1)

[Claims] 1. An injection mold that can be opened and closed, and an injection mold that surrounds the outer periphery of the mold and is movable in the direction of opening and closing of the mold, independently of the mold. An injection molding having a magnetic field, characterized in that it is equipped with a magnetic field coil for generating a magnetic field that anisotropizes a magnetic material in the direction of the magnetic field, and an injection nozzle that injects a synthetic resin material containing a magnetic material into the cavity. Device. 2. An injection molding apparatus having a magnetic field according to claim 1, wherein the magnetic field coil for generating a magnetic field is formed in an annular shape.