JP2001062885A - Mold clamping mechanism of injection molding machine for molding disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a disk molded article high in molding accuracy by applying uniform pressure to the entire disk molding surface of a cavity by efficiently applying the pressing force of a mold clamping ram to a mold. SOLUTION: An intermediate pressure member 20 having a pressing surface 21 including almost all of the disk molding surfaces D1, D2 of two or more disk molding cavities C1, C2 is arranged between the movable platen 12 and mold clamping ram 17 of an injection molding machine and the movable platen is inserted in the intermediate pressure member and ejector cylinders 31, 32 advancing and retreating with respect to the molding cavities of a movable mold are independently provided corresponding to the respective cavities.

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 molding a disk molded product, and more particularly to a mold clamping mechanism of a disk molding injection molding machine having two or more disk molding cavities in a molding die.

[0002]

2. Description of the Related Art For example, as shown in FIG.
A molding die 105 composed of a fixed die 103 attached to 1 and a movable die 104 attached to the movable plate 102
The above (two in this example) disk molding cavities C
An injection molding machine 100 having C1 and C2 is known. In the figure, reference numeral 106 denotes a mold clamping cylinder device, 107 denotes a mold clamping ram, 109 denotes a tie rod, 110 denotes an ejector cylinder device provided in the mold clamping ram, and 111 denotes an operation pin thereof.

In this injection molding machine 100, molded products are simultaneously formed in two disk molding cavities C1 and C2. However, as shown exaggeratedly in FIG. 5, the pressing surfaces 108 of the mold clamping ram 107 of the mold clamping cylinder device 106 against the movable platen 102 are all of the disk molding surfaces D1, D2 of the two disk molding cavities C1, C2. The mold clamping ram 107 during mold clamping.
Is concentrated on the center of the movable platen 102,
A phenomenon occurs in which the outer peripheral portion is bent. Such a phenomenon has a considerable influence on the molding accuracy of a thin disk-shaped molded product having a thickness of about 1 mm. In particular, since the molding of the disk molded product is performed by compression molding, it is desirable that the movable plate does not bend.

[0004] As a measure to cope with such a phenomenon,
It is conceivable to increase the area in contact with the movable plate by increasing the diameter of the mold clamping ram. In this case, (a) the mold opening / closing speed becomes slower, (b) the amount of oil increases, (c) The mold clamping force increases, and pressure control in the high pressure range is required.
(D) There are significant disadvantages in molding work and equipment, such as an increase in the size of the entire apparatus due to an increase in the size of the mold clamping cylinder, and (e) an increase in cost.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention has been proposed in order to solve such a problem, and the pressing force of a mold clamping ram is efficiently applied to a mold so that the cavity can be formed. An object of the present invention is to provide a mold clamping mechanism of a disk molding injection molding machine capable of pressing a whole surface of a disk molding surface with a uniform pressure and thereby obtaining a disk molded product with high molding accuracy. Another object of the present invention is to provide a mold clamping mechanism for a disk molding injection molding machine which has good workability in production and easy maintenance, and also has an advantage in taking out a disk molded product.

[0006]

That is, according to the first aspect of the present invention, there is provided an injection mold having two or more disk molding cavities in a molding die composed of a fixed die attached to a fixed plate and a movable die attached to a movable plate. In the molding machine, an intermediate pressing member having a pressing surface including substantially all of a disk forming surface of the two or more disk forming cavities is disposed between a movable platen of the injection molding machine and a mold clamping ram. In addition, an ejector cylinder device which inserts the movable plate and advances and retracts with respect to each molding cavity of the movable mold is provided independently corresponding to each cavity inside the intermediate pressing member. And a mold clamping mechanism of an injection molding machine for disk molding.

According to a second aspect of the present invention, in the first aspect, a gate cut cylinder device that moves forward and backward with respect to each of the disk molding cavities in the movable plate is independently provided corresponding to each cavity. The present invention relates to a mold clamping mechanism of a provided disk molding injection molding machine.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a plan view schematically showing a mold clamping mechanism of an injection molding machine according to one embodiment of the present invention, FIG. 2 is a cross-sectional view showing an enlarged main part thereof, and FIG. 3 is an intermediate pressing member and a disk molding cavity. FIG. 4 is a front view showing a relationship with a disk forming surface of FIG.

As shown in FIGS. 1 to 3, an injection molding machine 10 according to this embodiment has a molding die 15 comprising a fixed die 13 attached to a fixed platen 11 and a movable die 14 attached to a movable platen 12. Has two disk molding cavities C1 and C2. In this example, the two disk molding cavities C1 and C2 are arranged on the left and right (lateral direction). In the figure, reference numeral 16 denotes a mold clamping cylinder device, 17 denotes a mold clamping ram, and 19 denotes a tie rod.

In the present invention, the disk forming surfaces D1, D2 of the two disk forming cavities C1, C2 are provided between the movable platen 12 of the injection molding machine and the mold clamping ram 17.
Pressing member 2 having a pressing surface 21 covering substantially all of
0 is provided. 2 are fixing bolts for the intermediate pressing member 20. 3, the pressing surface 21 on the front surface of the intermediate pressing member 20 can be understood.
Are formed so as to cover (cover) substantially all of the disk forming surfaces D1 and D2 of the two disk forming cavities C1 and C2. In this example, the intermediate pressing member 20
The pressing surface 21 is formed in a rectangular shape approximately equal in size to the outer shape (outer dimension) of the movable die 14. 3 represents a pressing surface of the mold clamping ram 17.

As shown in FIG. 2, ejector cylinder devices 31 and 32 which penetrate the movable platen 12 and advance and retreat with respect to the molding cavities C1 and C2 of the movable mold 14 are provided inside the intermediate pressing member 20. Each cavity C1, C
2 are provided independently. Symbol 3 in FIG.
Reference numerals 3 and 34 denote ejector cylinders formed on the intermediate pressing member 20, 35 and 36 denote ejector pistons, 37A and 37B denote center pins for projecting sprues, and 38A and 38B denote ejector pins. The ejector pistons 35, 36 advance the center pins 37A, 37B, and then advance the ejector pins 38A, 38B. Reference numerals 39 and 40 denote insertion holes for ejector pistons 35 and 36 formed in the movable platen 12, 41 and 42, respectively.
Is a cylinder block.

In the example shown in FIG. 2, the gate cut cylinder devices 51, 52 which advance and retreat with respect to the disk forming cavities C1, C2 are further provided in the movable platen 12, as defined in the second aspect of the present invention. Each cavity C
1 and C2 are provided independently. Numerals 53 and 54 in the figure are gate cut cylinders, 55 and 56 are gate cut pistons, and 57A and 57B are gate cutters. In the illustrated embodiment, the molding die has two disk molding cavities. However, the same applies to the case where three or more disk molding cavities are provided.

In the mold clamping mechanism of the embodiment configured as described above, the mold clamping ram 17 of the mold clamping cylinder 16 clamps the movable platen 12 via the intermediate pressing member 20. At this time,
The pressing surface 21 of the intermediate pressing member 20 is formed to have a size that covers (covers) substantially all of the disk forming surfaces D1 and D2 of the two disk forming cavities C1 and C2. The tightening force is evenly transmitted to the disk forming surfaces D1 and D2 of the disk forming cavities C1 and C2, thereby enabling high-precision disk forming without unevenness.

In addition, since the ejector cylinder devices 31 and 32 are provided inside the intermediate pressing member 20 so as to correspond to the disk forming cavities C1 and C2, respectively, the molding cavities C1 and C2 are formed. It can be operated according to. In addition, by providing the ejector cylinder devices 31 and 32 on the intermediate pressing member 20, the ejector cylinder device does not have to be built in the mold clamping ram 17 which is a functional component as in the related art, and the production is greatly simplified. It becomes easy and the work efficiency such as maintenance is improved.

Further, in the structure in which the gate cut cylinder devices 51 and 52 are provided in the movable platen as in the second aspect of the present invention, there is no need to incorporate the gate cut cylinder device for each mold, so that equipment is required. Can be simplified and economical.

[0016]

As shown and described above, according to the mold clamping mechanism of the disk molding injection molding machine of the present invention, two or more disk molding cavities are formed between the movable platen and the mold clamping ram. Since the intermediate pressing member having the pressing surface covering substantially all of the surface is provided, the pressing force of the mold clamping ram is efficiently applied to the disk forming surface of the disk forming cavity, and the thin plate-shaped disk molded product is formed. The entire surface can be pressed with a uniform pressure, so that a disk molded product with high molding accuracy can be obtained.

In addition, since the ejector cylinder devices for inserting the movable plate and moving forward and backward with respect to each of the molding cavities of the movable mold are provided independently of each of the cavities inside the intermediate pressing member, each molded article is provided. The operation according to is possible. In addition, as compared with the conventional structure in which the ejector cylinder device is built in the mold clamping ram, the advantages in manufacturing are large and the work efficiency such as maintenance is remarkably improved.

Further, since the mechanism of the present invention can be implemented without any change in the structure of the mold clamping cylinder device and the mold clamping ram, it can be used in the conventional device as it is.
This is extremely advantageous in terms of manufacturing and cost.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing a mold clamping mechanism of an injection molding machine according to one embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a main part thereof.

FIG. 3 is a front view showing a relationship between an intermediate pressing member and a disk molding surface of a disk molding cavity.

FIG. 4 is a plan view schematically showing a mold clamping device of a conventional injection molding machine.

FIG. 5 is an exaggerated cross-sectional view showing a mold clamping state in a conventional mold clamping device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Injection molding machine 11 Fixed board 12 Movable board 13 Fixed mold 14 Movable mold 15 Mold 16 Mold clamping cylinder device 17 Mold clamping ram 20 Intermediate pressing member 21 Press surface 31, 32 Ejector cylinder device 51, 52 Gate cut cylinder device C1, C2 Disk forming cavity D1, D2 Disk forming surface

Claims (2)

[Claims] 1. An injection molding machine having two or more disk molding cavities in a molding die comprising a fixed die attached to a fixed platen and a movable die attached to a movable platen, wherein the movable platen and the die of the injection molding machine are provided. An intermediate pressing member having a pressing surface that covers substantially all of the disk forming surfaces of the two or more disk forming cavities is disposed between the clamping ram and the movable platen inside the intermediate pressing member. A mold clamping mechanism for an injection molding machine for disk molding, characterized in that ejector cylinder devices which are inserted into the movable mold and advance and retreat with respect to the molding cavities of the movable mold are provided independently corresponding to the respective cavities. 2. The disk forming apparatus according to claim 1, further comprising: a gate cut cylinder device that moves in and out of each of said disk forming cavities in said movable plate independently of said cavity. Mold clamping mechanism of injection molding machine.