JPH0624749B2 - Clamping mechanism of injection molding machine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping mechanism for an injection molding machine, and more particularly to a mold clamping mechanism for a vertical injection molding machine that opens and closes a mold vertically.

(Prior Art) Conventionally, as a mold clamping mechanism of this type of injection molding machine, for example, one shown in FIG. 3 is known.

In FIG. 3, when clamping the pair of molds 1 and 2,
Oil is supplied to the mold clamping cylinder 3 so that the piston rod 3a of the mold clamping cylinder 3 receives a force in the vertically downward direction in FIG. 3, so that the upper mold plate 4 and the mold 2 supporting the mold 1 are moved. The supporting lower die plate 5 is brought close to each other to clamp the dies 1 and 2. However,
Since a large force is required for mold clamping, a mold clamping cylinder 3 having a large diameter is used. Further, the mold clamping cylinder 3 is fixed to the lower mold plate 5, and the piston rod 3
A is guided and supported by the rod guide 3b and is fixed to the movable plate 6. Further, the movable plate 6 is connected to the upper die plate 4 via a tie bar 7 penetrating the lower die plate 5.

On the other hand, when the molds 1 and 2 are opened, the mold clamping cylinder 3
Oil is supplied to the mold clamping cylinder 3 so that the piston rod 3a of FIG. 3 is applied with the force in the vertically upward direction of FIG. 3, and the upper die plate 4 and the lower die plate 5 are separated from each other, and the die 1 2 is opened.

The vertical injection molding machine as described above can form an insert molding device together with, for example, a press molding machine. The insert molding device inserts a work press-molded by a press molding machine into a resin by an injection molding machine. When a vertical injection molding machine is used, the work is placed on a work path line indicated by a dotted line in FIG. Since the molding can be performed while moving, the device layout and the like can be facilitated.

(Problems to be Solved by the Invention) However, in such a conventional mold clamping mechanism of an injection molding machine, the running cost increases and the molding machine becomes large due to the reasons described below. There was a point.

That is, since the molds 1 and 2 are opened by the mold clamping cylinder 3, the stroke of the large diameter mold clamping cylinder 3 becomes long, and a large amount of oil is required to operate the mold clamping cylinder 3. Become. As a result, the discharge flow rate of the hydraulic pump that supplies oil to the mold clamping cylinder 3 increases, and a large hydraulic pump is required. Therefore, the running cost increases and the molding machine becomes large.

Further, since the large diameter piston rod 3a moves in a long stroke range, the length of the rod guide 3b becomes long,
In order to prevent the movable plate 6 and the rod guide 3b from colliding when the mold is opened, it is necessary to connect the upper die plate 4 and the movable plate 6 by separating them from each other. As a result, the work path line becomes high and the molding machine itself becomes large. In particular, when it is incorporated in an insert molding apparatus, it is necessary to match the work path line with the press molding machine or the like, so that an increase in the height of the work path line becomes a problem.

(Object of the Invention) Therefore, according to the present invention, by separately providing an opening / closing cylinder for opening and closing a mold and a mold clamping cylinder for clamping the mold via a block plate, the stroke of the mold clamping cylinder can be shortened and the cylinder can be operated. The objective is to reduce the amount of oil required, reduce running costs, and downsize the molding machine.

(Means for Solving the Problems) In order to achieve the above object, the present invention fixes a mold to a pair of die plates, and connects one die plate and a movable plate with a plurality of tie bars, In a mold clamping mechanism of an injection molding machine in which a tie bar guides the other die plate in a relatively movable manner, an opening / closing cylinder that is interposed between the other die plate and the movable plate, and that opens and closes the mold by a stretching operation, A block plate movably provided in the horizontal direction on the upper surface of the movable plate, a cylinder body fixed to the other die plate, and a piston rod which is slidably supported by the cylinder body and expands and contracts toward the movable plate. Consists of a mold clamping cylinder that applies a mold clamping force to the mold by abutting against the movable plate through a block plate, and a piston rod that can be inserted into the movable plate. It is characterized in that it is provided with a rod escape hole which has been cut.

(Operation) In the present invention, the stroke of the mold clamping cylinder is shortened to the length required for mold clamping, and the diameter of the opening / closing cylinder is reduced to the diameter required for mold opening, which is necessary for the operation of the mold clamping cylinder and the opening / closing cylinder. Oil capacity is reduced.

Therefore, the running cost is reduced and the molding machine is downsized.

(Example) Hereinafter, the present invention will be described with reference to the drawings.

1 and 2 are views showing an embodiment of a mold clamping mechanism of an injection molding machine according to the present invention, which is an example applied to an injection molding machine of an insert molding device for inserting a press-molded work into a resin.

First, the configuration will be described.

In FIGS. 1 and 2, 11 and 12 are a pair of molds,
11 is fixed to the upper die plate 13, and the mold 12 is fixed to the lower die plate 14. The upper die plate 13 is connected to the movable plate 16 by a plurality of tie bars 15, and the lower die plate 14 is guided by the tie bars 15 so as to be relatively movable along the axial direction of the tie bars 15.

Here, 17 is a die clamping cylinder fixed to the lower die plate 14, and the die clamping cylinder 17 is the lower die plate 14
Cylinder body 17a fixed to and cylinder body 17a
It has a piston rod 17b slidably supported on.
A predetermined hydraulic pressure is supplied to the mold clamping cylinder 17 from a hydraulic pump (not shown) under the control of a controller (not shown), and the cylinder body 17a and the piston rod 17b are mutually supplied by the supply of the hydraulic pressure. The mold clamping cylinder 17 expands and contracts by moving toward and away from each other.
A rod escape hole 16a is formed in the movable plate 16 so that the piston rod 17b can be inserted, and a block plate 18 can be moved in the horizontal direction in FIGS. 1 and 2 on the upper surface side of the movable plate 16 in FIGS. The block plate 18 is provided and driven by an air cylinder (not shown), and the operation of the air cylinder is controlled by the above-mentioned control device. The block plate 18 can cover the rod escape hole 16a as shown in FIG. 1 and expose the rod escape hole 16a as shown in FIG. 2 depending on its moving position. When the rod escape hole 16a is covered by the block plate 18,
When the piston rod 17b can abut the movable plate 16 via the block plate 18 and the rod escape hole 16a is exposed, the movable plate 16 and the piston rod 17b do not abut each other, and the piston rod 17b does not come into contact with the rod escape hole. The movable plate 16 can be freely inserted along the axial direction of the tie bar 15, and can be inserted into the 16a. That is, by covering the rod escape hole 16a with the block plate 18 and applying a predetermined hydraulic pressure to the mold clamping cylinder 17, the mold clamping cylinder 17 collides with the movable plate 16 and the lower mold plate 14 and the upper mold die are joined. The plates 13 can be brought close to each other to apply a mold clamping force to the molds 11 and 12.

Reference numeral 19 denotes an opening / closing cylinder interposed between the lower die plate 14 and the movable plate 16. The opening / closing cylinder 19 is slidably supported by a cylinder body 19a fixed to the lower die plate 14 and a body 19a. It is composed of a piston rod 19b connected to the movable plate 16. Further, a predetermined hydraulic pressure is supplied from the hydraulic pump to the opening / closing cylinder 19 by the control of the above-mentioned control device, and the hydraulic pressure causes the cylinder body 19a and the piston rod 19b to move toward or away from each other. The opening / closing cylinder 19 expands and contracts. That is, by exposing the rod escape hole 16a, the opening / closing cylinder
When a predetermined hydraulic pressure is supplied to 19, the opening / closing cylinder 19 separates the lower die plate 14 and the upper die plate 13 from each other by the expansion / contraction operation (the contraction operation in this embodiment) without being hindered by the movable plate 16. The molds 11 and 12 can be opened.

On the other hand, the insert-molded work (not shown) moves on the work path line shown by the dotted line in FIGS.
It is designed to be inserted into resin by injection molding of this molding machine. In addition, the above-mentioned control device synchronizes with the movement of the work as described in the operation below,
In addition to controlling the operation of the opening cylinder 17 and the opening / closing cylinder 19 and the operation of the air cylinder described above, the operation of an injection nozzle (not shown) for injecting resin into the molds 11 and 12 is controlled. In addition,
20 is a potentiometer.

Next, the operation will be described.

First, as shown in FIG. 2, when the rod escape hole 16a is exposed by the movement of the block plate 18 and the molds 11 and 12 are opened by the operation of the opening / closing cylinder 19, (at this time, the mold clamping cylinder Piston rod 17b is rod escape hole 16a
Inserted in. ) The press-formed work moves on the work path line and is placed at a predetermined position between the molds 11 and 12. Then, by operating the opening / closing cylinder 19, the mold 11,
When the block plates 18 are moved to bring the rod escape holes 16a into contact with each other after the 12 are brought close to each other, the molds 11 and 12 are clamped by the operation of the mold clamping cylinder 17 as shown in FIG. Resin is injected and filled into the molds 11 and 12. Then, when the mold clamping of the molds 11 and 12 is loosened by the operation of the mold clamping cylinder 17, the block plate 18 is moved and the rod escape hole 16a is exposed.
The mold is opened, and the insert-molded molded product is taken out. By repeating the above-mentioned operation, insert-molded products are automatically molded one after another.

As described above, according to the present embodiment, since the opening / closing cylinder 19 for opening / closing the mold and the mold clamping cylinder 17 for clamping the mold via the block plate 18 are separately provided, the stroke of the mold clamping cylinder 17 is The length required for clamping, that is, the length required for mold opening can be made extremely short, and the capacity of the mold clamping cylinder 17 can be reduced. Further, since the opening / closing cylinder 19 only needs to generate a force necessary for mold opening, the diameter of the opening / closing cylinder 19 can be reduced and the capacity of the opening / closing cylinder 19 can be reduced. Furthermore, the mold clamping cylinder 17 and the opening / closing cylinder
The discharge flow rate of the hydraulic pump that supplies oil to 19 can be reduced, and the hydraulic pump can be downsized. Therefore, the running cost of the molding machine can be reduced and the molding machine can be downsized.

Further, since it is not necessary to move the piston rod 17b with a long stroke and the piston rod 17b can be escaped by the rod escape hole 16a when the mold is opened, compared with the conventional one, the upper die plate 13 and the movable plate 16 are The separation distance can be shortened and the work path line can be lowered. Therefore, the molding machine can be downsized, and the layout of the insert molding device can be facilitated.

(Effect) According to the present invention, since the opening / closing cylinder for opening / closing the mold and the mold clamping cylinder for clamping the mold via the block plate are separately provided, the stroke of the mold clamping cylinder is reduced to the length required for the mold clamping. In addition to shortening, the diameter of the opening / closing cylinder can be reduced to the diameter required for mold opening, and the amount of oil required for operating the mold clamping cylinder and the opening / closing cylinder can be reduced.

Further, since the piston rod can be escaped by the rod escape hole at the time of mold opening, the distance between one die plate and the movable plate can be shortened and the work path line can be lowered. Therefore, the running cost can be reduced and the molding machine can be downsized.

[Brief description of drawings]

1 and 2 are views showing an embodiment of a mold clamping mechanism of an injection molding machine according to the present invention, and FIG. 1 is a front view of the mold clamping process,
FIG. 2 is a front view when the mold is opened, and FIG. 3 is a front view of a mold clamping mechanism of a conventional injection molding machine. 11, 12 …… Mold, 13 …… Upper die plate (a pair of die plates), 14 …… Lower die plate (a pair of die plates), 15 …… Tie bar, 16 …… Movable plate, 18 …… Block plate, 16a ... Rod escape hole, 17a ... Cylinder body, 17b ... Piston rod, 17 ... Mold clamping cylinder, 19 ... Open / close cylinder.

Claims (1)

[Claims] 1. A die is fixed to each of a pair of die plates, one die plate and a movable plate are connected by a plurality of tie bars, and the other die plate is guided so as to be relatively movable. In the mold clamping mechanism of the injection molding machine, an opening / closing cylinder that is interposed between the other die plate and the movable plate and that opens and closes the mold by expansion and contraction, and a block that is horizontally movable on the upper surface of the movable plate. A plate, a cylinder body fixed to the other die plate, and a piston rod slidably supported by the cylinder body and extending and contracting toward the movable plate, and abutting against the movable plate via the block plate. A mold clamping cylinder that applies a mold clamping force to the mold, and a rod escape hole provided in the movable plate so that the piston rod can be inserted therein. Molding machine of mold clamping mechanism.