JPH07186217A - Injection-molding machine - Google Patents

Abstract

PURPOSE:To make an injection-molding machine compact and miniaturized by accommodating pistons with a piston rod for driving a movable plate in each independent cylinder chamber and arranging a cylinder at the corner of a fixed plate. CONSTITUTION:A piston rod 45 for driving a movable plate 3 has pistons 46, 46, and each piston 46, 46 is accommodated in each independent cylinder chamber 40a, 40b. A cylinder 41 is arranged at the corner of a fixed plate 2, and the center of the fixed plate 2 is widely open. Consequently, the movable plate 3 can be tightened by a force coupled with the pressure of a hydraulic oil applied to each piston 6. Thus it is possible to obtain a high clamping force without enlarging the diameter of the cylinder 41. Further, it is possible to shorten the length of the machine compared to a conventional molding machine using a toggle mechanism, because an injection unit can be arranged unrestrictedly in the central open part of a fixed part.

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 using a cylinder device as a mold clamping mechanism.

[0002]

Prior Art and Problems to be Solved by the Invention FIG.
Shows a conventional horizontal injection molding machine, in which a fixed plate (2) and a movable plate (3) capable of approaching and separating from the fixed plate (2) are provided on a base (1), and both plates face each other. The mold (21) (31) is fixed to the surface.

A mounting plate (71) is fixedly arranged behind the movable plate (3), and the movable plate (3) and the mounting plate (71) are connected by a toggle mechanism (7) to the mounting plate (71). The piston rod of the deployed drive cylinder device (72) is connected to the toggle mechanism (7) to form the slide drive device (4) of the movable plate (3). The drive cylinder device (72) operates the toggle mechanism (7) to slide the movable plate (3) to perform mold clamping and mold opening.

The conventional injection molding machine described above has a movable plate.
The toggle mechanism (7) must be placed outside the (3) and the injection unit (5) must be placed outside the fixed plate (2), which increases the length of the machine.

A fixed plate instead of the toggle mechanism (7)
A cylinder device (not shown) is provided on the injection unit (5) side of (2), and a tie rod (20) slidably penetrating the fixed plate (2) from the movable plate (3) is connected to the cylinder device. An injection molding machine for slidingly driving the movable plate (3) has also been implemented.

However, in order to obtain the required tightening force during mold clamping, the effective diameter of the cylinder of the cylinder device must be increased, and the injection unit (5) is provided outside the fixed plate (2). The height and width of the molding machine must be large in order to avoid interference between the two.

That is, the molding machine cannot be downsized regardless of whether the toggle mechanism (7) or the cylinder device is used as the mold clamping device, and a large installation space is required. The present invention clarifies an injection molding machine that can be made much smaller than the conventional one if the performance is the same.

[0008]

An injection molding apparatus according to the present invention comprises a base.
A fixed plate (2) and a movable plate (3) facing the fixed plate (2) are arranged on the (1) so that they can approach and separate from each other, and can be moved by a slide drive device (4) linked to the movable plate (3). In an injection molding machine that slides the plate (3) to clamp or open the mold on the plates (2) and (3), the slide drive device (4) of the movable plate (3) is
A plurality of cylinders (41) divided into a plurality of cylinder chambers (40a) (40b) in the axial direction are fixed to the corners of the outer surface of the fixing plate (2), and the cylinder chambers (41) of each cylinder (41) are fixed. A piston rod (45) that slidably penetrates a series of 40a (40b) is slidably penetrated to the fixed plate (2) to connect the tip to the movable plate (3). Pistons (46) (46) that slide in the cylinder chambers (40a) (40b) are provided.

[0009]

[Operation and effect] The piston rod (45) for driving the movable plate (3) has a plurality of pistons (46) (46), and each piston (46) (46) is provided in an independent cylinder chamber (40a). ) (40b), the movable plate (3) can be tightened with the force of the working oil applied to each piston (46), so that the diameter of the cylinder (41) does not have to be increased. , High tightening force can be obtained.

Since the cylinder (41) is arranged near the corner of the fixed plate (2) and the central portion of the fixed plate (2) is largely open, the injection unit (5) is easily opened in the open portion.
Can be deployed. Therefore, the machine length can be shortened compared with the conventional molding machine using the toggle mechanism (7), and the injection unit (5)
And the large diameter cylinder device for mold clamping do not interfere,
Compared to a molding machine with a large width, it has the advantages of a low machine height and a small machine width, and can be installed in a narrower space than before.

[0011]

EXAMPLE As shown in FIG. 1, a rectangular fixed plate (2) is erected on a base (1), and a rectangular movable plate (3) is provided so as to be able to approach and separate from the fixed plate (2). To do. The fixed side mold (21) and the movable side mold (31) are attached to the inner surfaces of the fixed plate (2) and the movable plate (3) facing each other.

On the outer surface of the movable plate (3), an ejector cylinder device (6) for removing the molded product from the mold is provided. Hydraulic clamping devices are provided at four corners of the outer surface of the fixed plate (2) to form the mold clamping drive device (4).

In the cylinder (41) of each hydraulic cylinder device, a plurality of, in the embodiment, two cylinders (41a) (41b) are connected with a partition plate (42) sandwiched therebetween, and both cylinders (41a) (41a) End plates (43) (44) on the outer edge of 41b)
The cylinders (41a) and (41b) are formed by attaching, and are independent cylinder chambers (40a) and (40b).

As shown in FIG. 2, the cylinder (41) is attached to the fixed plate (2) through the end plate (43) at the inner end, and the cylinder (41) has the end plate (43) and the partition. A piston rod (45) is slidably provided through the plate (42), and a tip of the piston rod (45) slidably penetrates through the fixed plate (2) and is connected to the movable plate (3). .

The piston rod (45) has pistons (46) (46) that slide in the cylinder chambers (40a) (40b). A working oil inlet and a drain (not shown) are provided at both ends of each cylinder (41a) (41b) of the cylinder (41).

On the base (1), the above four cylinders (41)
Injection unit that can approach and separate from the fixed plate (2) in between
(5) has been deployed. Two nozzle touch cylinder devices sandwiching the injection unit (5) on the fixed plate (2).
(51) is deployed and linked to the injection unit (5). The material hopper (52) of the injection unit (5) is located between the upper two cylinders (41) of the four cylinders (41).

However, the piston rod (45) for driving the movable plate (3) has a plurality of pistons (46) (46), and each piston (46) (46) has an independent cylinder chamber (40a). ) (40
Since it is housed in b), the movable plate (3) can be tightened with the force of the working oil applied to each piston (46), so that the cylinder (41) is high without increasing its diameter. A tightening force can be obtained.

Since the cylinder (41) is arranged near the corner of the fixed plate (2) and the central portion of the fixed plate (2) is largely open, the injection unit (5) can be easily opened in the open portion.
Can be deployed. Therefore, the machine length can be shortened compared with the conventional molding machine using the toggle mechanism (7), and the injection unit (5)
Compared with a molding machine in which the height is increased so that the large-diameter mold clamping cylinder device does not interfere, the machine height can be lowered, and there is an advantage that it can be installed in a narrow space compared to the conventional machine.

When a hydraulic pump having a fixed capacity is used to supply working oil to the cylinder chambers (40a) (40b) of each cylinder (41) all at once, and the piston rod (45) is moved in the mold clamping direction. , Clamping speed is slow. Therefore, from the start of mold clamping to immediately before mold clamping, the working oil is forcibly sent to one of the cylinder chambers, and the working oil is sucked into the other cylinder chamber by the suction force generated by the movement of the piston. During mold clamping, if each cylinder is operated by a hydraulic circuit that can forcibly feed working oil into both cylinder chambers (40a) (40b) and raise the pressure to the set pressure by the pressure adjustment valve. The time to mold clamping can be shortened and the required pressure for mold clamping can be secured.

FIG. 4 shows another embodiment in which the inner diameters of the cylinders (41a) and (41b) of the cylinder (41) are different. In this case, at the beginning of the mold clamping, the small diameter cylinder can be used to increase the speed of the movable plate (3), and the large diameter cylinder can be used immediately before the mold clamping. It can be done speedily.

The present invention is not limited to the above horizontal type injection molding machine, and the movable plate and the fixed plate are vertically opposed to each other, and the movable plate is moved up and down to clamp the mold.
Needless to say, the present invention can be applied to a vertical injection molding machine that opens a mold, and various modifications can be made within the scope of the claims.

[Brief description of drawings]

FIG. 1 is a front view of an injection molding machine of the present invention.

FIG. 2 is a sectional view of a cylinder device.

FIG. 3 is a side view of the injection molding machine of the present invention.

FIG. 4 is a sectional view of a cylinder device according to another embodiment.

FIG. 5 is a front view of a conventional example.

[Explanation of symbols]

 (2) Fixed plate (3) Movable plate (41) Cylinder (45) Piston rod (46) Piston (5) Injection unit

Claims (1)

[Claims] 1. A slide in which a fixed plate (2) and a movable plate (3) facing the fixed plate (2) are arranged on the base (1) so as to be close to and away from each other, and are connected to the movable plate (3). The movable plate (3) is slid by the driving device (4),
In an injection molding machine that clamps a mold on a plate (2) or (3) or opens a mold, a slide drive device (4) of a movable plate (3) has a plurality of cylinder chambers (in the axial direction). 40a)
A plurality of cylinders (41) divided into (40b) are fixed to the corners of the outer surface of the fixing plate (2), and the cylinder chambers (40a) (40b) of each cylinder (41) can be slid in series. The penetrating piston rod (45) is slidably passed through the fixed plate (2) to connect the tip to the movable plate (3), and the cylinder chambers (40a) (40b) are slid on the piston rod (45). An injection molding machine equipped with pistons (46) (46).