JPH0729340B2 - Mold mounting structure in injection molding machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding machine for filling a mold with molten resin for molding, and more particularly to a structure for mounting a mold.

[0002]

2. Description of the Related Art Conventionally, in an injection molding machine, a fixed die plate and a movable die plate of a mold are attached to a fixed die plate and a movable die plate, which are supported by four tie bars, respectively, and are arranged to face each other. In addition, a mold clamping cylinder is provided so that the moving die plate can be driven on the tie bar, and an injection unit for filling the mold with molten resin is provided on the fixed die plate side. Further, a guide pin and a fitting hole for the guide pin are relatively formed between the fixed-side mold plate and the movable-side mold plate of the mold, so that the guide pin can obtain mold matching accuracy. .

The movable die plate is driven by the operation of the mold clamping cylinder to close the mold, and the molten resin is filled in the mold by the injection unit in the mold clamped state. The mold clamping force is tie bar. It is being transmitted.

[0004]

By the way, for example, in molding an audio disk or the like, a highly accurate mold matching (centering of the mold) technique is required. In the conventional structure as described above, the guide pin is used. Since so-called centering accuracy on the machine side based on the tie bar is required in addition to the matching accuracy based on the tie bar, the accuracy providing element is dual and requires a high degree of skill.

Further, as shown in FIG. 6, the die plate 7
The area of the die 72 attached to 0 is regulated by the presence of the tie bar 74, and the effective molding area S is regulated by the presence of the guide pin 76, and the low space utilization rate of the die is pointed out. Has been done.

According to the consideration of the inventor of the present invention, it is possible to integrate the tie bar function for transmitting the mold clamping force and the guide pin function for the mold matching. Can be expected to improve.

Therefore, an object of the present invention is to provide a die mounting structure in an injection molding machine, which enables the die centering to be performed with high accuracy without requiring skill and the space utilization rate of the die can be improved. And

[0008]

SUMMARY OF THE INVENTION The present invention was devised to achieve the above-mentioned object, and its characteristic feature is that a pair of metal molds are coaxially formed by co-casting by punching in a mold-matching state. The shaft holes located at the respective positions are formed at two positions, and one of the molds is provided with a guide rod for transmitting the mold clamping force slidably in each of the shaft holes, the misalignment of which is regulated by a bearing member. At the free end of the guide rod, the other mold is inserted and fixed in the shaft hole without reducing the diameter of the free end, and is supported only by the free end.

Further, according to the present invention, the guide rod may be an advancing / retreating rod of the mold clamping cylinder.

[0010]

According to the present invention, one die moves along the axis of the guide rod that also serves as a tie bar and a guide pin by the operation of the die clamping cylinder to close the die and perform die clamping. In this case, a guide rod is slidably provided with a bearing member whose center misalignment is regulated through a shaft hole formed on the coaxial center by co-alignment processing, and one of the molds has only two guide rods. Since it is supported, a decrease in accuracy due to sliding wear of the guide rod can be avoided, and the accuracy-improving element can be minimized to improve the mold matching accuracy. Further, since the structure is a direct support structure not via the die plate, the effective molding area of the mold is expanded.

Further, according to the present invention, the advancing / retreating rod of the mold clamping cylinder doubles as the guide rod, thereby simplifying the structure.

[0012]

1 to 5 show an embodiment of the present invention and show an example of application to a disk molding machine for molding a so-called disk-shaped recording medium such as a video disk or an audio disk.

A molding machine main body 6 is installed on the bed 4 of the disk molding machine 2, and a mold 8 is attached to the molding machine main body 6.
And a support bracket 1 having one end fixed on the bed 4
Two parallel support shafts 12 and 12 attached to 0, and an injection unit 14 horizontally mounted between these support shafts 12 and 12.
And a mold clamping cylinder 1 whose one end is connected to the support shafts 12 and 12 and the other end is supported by one of the molds 8.
6 and 16 are provided.

The mold 8 is fixed to the bed 4 and has a fixed mold 18 for holding the mold clamping cylinders 16, 16.
Advancing / retreating rods 16a, 16 of mold clamping cylinders 16, 16 as guide rods that also serve as conventional tie bars and guide pins
It is composed of a movable mold 20 fixed to a.
Reference numeral 18a indicates a nozzle guide hole.

The advancing / retreating rod 16a, as shown in FIG.
The stationary-side mold 18 and the movable-side mold 20 are inserted into shaft holes 18b and 20a formed coaxially by so-called co-alignment processing.
9 is supported so as to be able to slide smoothly in a state where the misalignment due to sliding wear is restricted.

The injection unit 14 has an injection cylinder, a screw, and the like, and a unit main body 22 provided so as to be movable in the axial direction of the support shaft 12 by a drive source such as a hydraulic cylinder.
And a material supply device 24 such as a hopper, and a heating cylinder 28 having a nozzle 26 at its tip and positioned between the mold clamping cylinders 16 and 16.

Next, the molding operation of the disk molding machine 2 will be described. As shown in FIG. 5, the movable side mold 20 is moved by the retreat of the advancing / retreating rods 16a, 16a to close the mold, and the injection unit 14 is moved so that the nozzle 26 touches the fixed side mold 18. Done. The resin is filled into the mold 8 with the mold clamped. The mold opening is performed by the forward movement of the advancing / retreating rods 16a, 16a.

According to the above construction, the fixed side mold 18 and the movable side mold 20 are directly supported by the advancing / retreating rod 16a serving as a guide rod which also serves as a tie bar and a guide pin, so that the mold 8 and the molding machine are supported. The accuracy on the side is unified, and also
A shaft hole 18b formed on the coaxial center by co-processing,
The advancing / retreating rod 16a is connected to the bearing member 19 via 20a.
Since the center of the die is slidably provided and the movable die is inserted into the shaft holes of the two advancing / retreating rods 16a and supported only by the advancing / retreating rods 16a, the core of the die 8 is The dispensing can be performed easily without requiring skill and the accuracy is improved.

Further, the effective molding area of the mold 8 can be increased by eliminating the need for guide pins.

Further, in this example, since the advancing / retreating rod 16a of the mold clamping cylinder 16 itself serves as a guide rod, the structure can be simplified.

Next, the structure of the mold 8 will be described with reference to FIG. A sprue bush 30 is attached to the central portion of the fixed-side mold 18, and a fixed-side mirror surface portion 32, which is one of the components of the cavity, is fitted to the sprue bush 30 on the die-opposing surface and the outer peripheral portion is fixed by a bolt 34. It is fixed and attached. Although not explicitly shown in the figure, the fixed-side mirror surface portion 32
A stamper as a transfer base material is attached to the stamper, and the stamper is an inner pressing member (not shown).
And an outer peripheral pressing member 36.

The outer peripheral pressing member 36 is composed of a ring member 38 which doubles as a spacer between the molds and seals the outer peripheral region of the cavity, and a stamper holding portion 40 which is integrally formed on the inner peripheral surface of the ring member 38. There is. Further, screw holes 38a are formed on both sides of the ring member 38,
The through bolt 42 penetrating the fixed-side mold 18 or the movable-side mold 20 can be arbitrarily attached and converted to either the fixed-side mold 18 or the movable-side mold 20 without requiring a manual holding operation. ing.

As a result, the labor required for replacing the stamper can be reduced, and the replacement work can be performed easily and smoothly. That is, in the conventional structure, since it is configured to be attached to and detached from only one of the template plates, it is necessary to hold the outer peripheral pressing member 36 which is a heavy object during the stamper replacement, but it is possible to move it by replacing the through bolt 42. It can be temporarily temporarily fixed to the side mold 20 and can be reattached to the fixed mold 18 without a holding operation by replacing and tightening the through bolt 42 again in the mold closed state. Reference numerals 18c and 20b denote through holes for the through bolt 42.

On the other hand, a gate cut member 44 is attached to the central portion of the movable die 20, and a movable mirror surface portion 46 which is the other component of the cavity is attached to the die facing surface. The gate cut member 44 is composed of a cylinder member 48 fixed to the movable die 20, and a cut pin 50 having a sprue ejector pin and capable of moving forward and backward in the cylinder member 48.
The movable side mirror surface portion 46 is fitted into the cylinder member 48, and the outer peripheral portion is fixed by bolts 52.

Mounting hole 20c for the gate cut member 44
And the mounting hole 18d of the sprue bush 30 is moved forward and backward by the rod 1
Simultaneously with the shaft holes 18b and 20a of 6a, they are formed on the coaxial center by co-alignment processing, whereby the mold alignment is maintained with high accuracy.

In the above example, an example of application to disk molding is shown, but the invention is not limited to this and can be applied to other molding. Further, in the above example, the advancing / retreating rod 16a of the mold clamping cylinder 16 is used as a guide rod. However, of course, the guide rod directly supports the fixed side mold 18 and the movable side mold 20, and the advancing / retreating rod 16a is movable. It can also be configured to be connected to the mold 20.

[0027]

According to the present invention, the guide rod for transmitting the mold clamping force can be made to have the functions of the tie bar and the guide pin, so that the precision of the mold can be unified.
Further, two guide rods are slidably provided through a shaft hole formed on the coaxial center by co-alignment processing in a state where misalignment is regulated by a bearing member, and a free end of the guide rod is provided in one mold. Since it is configured to be inserted and fixed in the shaft hole without being reduced in diameter and to be supported only by the free end, centering of the mold can be easily performed without requiring skill and accuracy can be improved. It is possible to improve. Moreover, since there is no guide pin, the effective molding area of the mold can be increased.

Further, according to the present invention, since the advancing / retreating rod of the mold clamping cylinder serves as a guide rod, it is possible to simplify the structure by reducing the number of parts.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of a die mounting structure in an injection molding machine according to the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a side view of the same.

FIG. 4 is a schematic sectional view of a mold.

FIG. 5 is a plan view of a mold in a closed state.

FIG. 6 is a schematic view showing a conventional mold mounting structure.

[Explanation of symbols]

 8 mold 16 mold clamping cylinder 16a advancing / retreating rod (guide rod) 18 fixed mold 20 movable mold

Claims (2)

[Claims] The method according to claim 1] oppositely disposed pair of molds to mold clamping by the clamping cylinder, in an injection molding machine for performing molding with the molten resin into the mold, the mold together to both of the pair of molds Status
Axial hole located on the coaxial center by co-machining process
Are formed in two places, and one of the molds has a guide rod for transmitting the mold clamping force to each shaft hole by a bearing member.
Is restricted misalignment slidably disposed, said Gaidoro
The other mold is attached to the free end of the lid, and the free end is attached to the shaft hole.
It is inserted and fixed without reducing the diameter and
A die mounting structure in an injection molding machine, which is supported only at a free end . 2. The mounting structure for a mold in an injection molding machine according to claim 1, wherein the guide rod is an advancing / retreating rod of a mold clamping cylinder.