JPS6357215B2 - - Google Patents

Description

Detailed Description of the Invention <Technical Field> The present invention relates to a mold clamping device for clamping a mold used in injection molding or the like.

<Prior art> Conventionally, a mold clamping device used for this type of molding connects a pressing means such as a hydraulic cylinder directly to the movable mold, operates the pressing means, and presses the movable mold against the fixed mold to close the mold. It is used to tighten the mold, and if a higher mold clamping force is required, it is necessary to replace it with a pressing means that can generate a higher pressing force.

<Object of the Invention> The present invention adds a boosting mechanism with a simple structure to the conventional pressing means, and easily clamps the mold with a pressing force higher than that of the pressing means without replacing the pressing means itself. The purpose is to provide a mold clamping device that can perform this type of mold clamping.

<Structure of the Invention> The gist of the invention is that on the back side of the movable mold, which is provided opposite to the fixed mold, there is provided a pressing plate connected to a pressing means, and an elastic body that urges the pressing plate and the movable mold to be separated from each other. A bar having a rotating shaft is attached to the pressing plate, a hook is formed at the tip of the bar, and the bar is movably connected via a slidable pivot near the tip of the bar. Furthermore, a lock plate that engages with the bar hook is arranged and fixed at a side position of the bar hook when the mold is closed, and when the mold is closed, the bar hook moves in a direction substantially perpendicular to the moving direction of the movable mold to lock the mold. A mold that engages with a plate and presses the movable mold against the fixed mold using the engaging part as a fulcrum, the pivot point between the press plate and the bar as a force point, and the pivot point between the bar and the movable mold as a point of action. It is in the tightening device.

<Example> Fig. 1 is a perspective view of a mold clamping device showing one embodiment of the present invention, Figs. 2a to 2d are schematic front views sequentially showing the operating mode of the same embodiment, and Fig. 3 is a schematic front view of the same embodiment. It is a schematic front view showing the time of mold clamping.

The mold clamping device of the embodiment is installed in an injection molding machine, and a table 1b with legs (not shown) is provided with a frame 1 at a position facing each other with tie bars 9, and a fixed mold 2 is mounted on the lower surface of the table 1b. is fixed, and furthermore, four holding rods 4 are provided protruding downward from the four corners of the table 1b, a holding plate 6 is fixed to the tip of the holding rod 4, and a hydraulic cylinder 5 is attached to the holding plate 6 to move the rods 5a upward. It is held fixedly towards the target.

A pressure plate 7 connected to the rod 5a of the hydraulic cylinder 5 is disposed on the back side of the movable mold 3 (lower side in FIG. 1), which is provided opposite to the fixed mold 2. An elastic body 8 such as a coil spring that urges the movable mold 3 upward is provided between the movable mold 3 and the movable mold 3
is mediated.

Near both sides of the front and rear end faces of the pressing plate 7 in FIG. It is mounted on a shaft with a

This bar 12 has a movable type 3 near its tip.
The movable mold 3 is movable in a direction perpendicular to the direction of movement of the movable mold 3 (horizontal direction in FIG.
is connected to. Specifically, a sliding hole 3b is formed in a flange portion 3a fixed below the movable mold 3 in a direction perpendicular to the moving direction of the movable mold 3, and a sliding hole 3b is provided protruding from the bar 12 and fitted into the sliding hole 3b. Pin 1 to be inserted
2b, this pivot portion 13 is constructed. Note that, if the bar 12 has sufficient strength, the pivot portion 13 may be constructed by providing a sliding hole in the bar 12 and a pin protruding from the movable flange portion 3a.

And, on the table 1b, there is a bar hook part 1 when the mold is closed.
A lock plate 14 is disposed and fixed on the side of bar hook 12a and can be engaged with bar hook 12a.

Note that 16 is an injection cylinder.

Next, the operation mode of the mold clamping device of the embodiment will be explained (see Figures 2a to 2d).

First, when the mold is opened, the movable mold 3 is urged and supported by the elastic body 8 interposed between the movable mold 3 and the pressing plate 7, as shown in FIG. 2a.

Then, the hydraulic cylinder 5 operates, and the rod 5a
When pushed up, the pressing plate 7 brings the movable mold 3 closer to the fixed mold 2 through the elastic body 8, and further brings the movable mold 3 into contact with the fixed mold 2 (Fig. 2b).

Thereafter, when the rod 5a of the hydraulic cylinder 5 is further pushed up, the pressing plate 7 rises against the biasing force of the elastic body 8. At this time, the bar 12 pivoted to the press plate 7 is rotated so as to narrow the angle with the press plate 7, and the vicinity of the tip is connected to the movable die 3 via the pivot portion 13.
Since they are connected so as to be movable only in the direction orthogonal to the moving direction, the hook portions 12a move to the sides substantially orthogonal to the moving direction of the movable mold 3 and engage with the lock plates 14 (see Fig. 2c). ).

Then, when the rod 5a of the hydraulic cylinder 5 is operated to push up the rod 5a, the pressing plate 7 is further pressed upward, but the pressing force is less than the bar 12.
The movable mold 3 is used as a lever to clamp the movable mold 3 (Fig. 2d). To explain this effect,
As shown in FIG. 3, the bar 12 is connected to the pressing plate 7
is pivoted by a pin 11 to the hook portion 12a.
is engaged with the lock plate 14, and the vicinity of the tip of the bar 12 is connected to the movable mold 3 through the pivot portion 13 so that movement in the moving direction of the movable mold 3 is restricted.
Pressing force F of the pressing plate 7 by the hydraulic cylinder 5
1, the engagement part between the hook part 12a and the lock plate 14 is the fulcrum A, the pivoting part between the bar 12 and the pressing plate 7 is the force point B, and the pivoting part between the bar 12 and the movable mold 3 is the action point C. Using the bar 12 as a lever, the movable mold 3 is pressed against the fixed mold 2 by the mold clamping force F2. By the way, if l1:l2=5:1, F2
=F1×l1/l2=5F1, and a clamping force five times the pressing force of the hydraulic cylinder 5 can be obtained.

Therefore, mold clamping can be performed with a pressing force higher than that of the hydraulic cylinder 5 without replacing the hydraulic cylinder 5, which is the pressing means.

After the molded product is molded, when the rod 5a of the hydraulic cylinder 5 is retracted, the mold is opened in an operation completely opposite to the previously described process, and the molded product is taken out.

In the embodiment, a hydraulic cylinder is used as the pressing means, but other means such as a screw, a rack and pinion, etc. may be used.

In addition, in the embodiment, the pressing plate 7 and the movable mold 3
A total of four bars 12 are used to intersect with the front and rear end surfaces of the press plate 7, but the number of bars 12 is different from the movable type 3.
If the mold is small and a guide mechanism or the like is provided to ensure smooth mold clamping, only one can be used. Note that if a plurality of molds (preferably an even number) are provided symmetrically around the movable mold 3 as in the embodiment, the mold clamping force is equally applied to the left and right sides, so that uniform mold clamping can be performed.

Furthermore, in the embodiment, an elastic body 8 that urges the press plate 7 and the movable die 3 to separate from each other is interposed between the press plate 7 and the movable die 3, but this elastic body 8 is the bar 12 when the mold is closed.
Since the bar 12 is provided to enable lever action, the same effect can be obtained even if it is provided between the press plate and the bar so that the tip of the bar 12 separates from the press plate 7.

<Effects of the Invention> In the mold clamping device according to the present invention, when the mold is closed, the bar, which is pivotally attached to the press plate and movably connected via a pivot near the tip, locks the tip of the bar with the lock plate. In order to press the movable mold against the fixed mold by using the engaging part as a fulcrum, the pivoting part with the pressing plate as a force point, and the pivoting part of the movable mold as a point of action, Without replacing the pressing means for pressing the pressing plate, only a boosting mechanism with a simple structure is added, and the mold can be easily clamped with a pressing force higher than that of the pressing means.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a mold clamping device showing one embodiment of the present invention, Figs. 2a to 2d are schematic front views sequentially showing the operating mode of the same embodiment, and Fig. 3 shows the mold clamping device of the same embodiment. It is a schematic front view shown. 2... fixed type, 3... movable type, 5... (pressing means) hydraulic cylinder, 7... pressing plate, 8...
Elastic body, 12... Bar, 12a... Hook portion, 13...
...Pivotal part (3b...sliding hole, 12b...pin),
14... Lock plate, A... Fulcrum, B... Force point, C... Point of action.

Claims (1)

[Claims] 1. A pressing plate connected to a pressing means and an elastic body urging the pressing plate and the movable mold to be separated from each other are disposed on the back side of the movable mold provided opposite to the fixed mold. A bar having a rotating shaft is attached to the plate, and a hook portion is formed at the tip of the bar, and near the tip of the bar, it is connected to the movable mold via a slidable pivot portion, and the bar is connected to the movable mold via a slidable pivot portion. A lock plate that engages with the bar hook is arranged and fixed at a lateral position of the bar hook when the mold is closed, and when the mold is closed, the bar hook moves in a direction substantially perpendicular to the moving direction of the movable mold. The movable mold is engaged with the lock plate, and the movable mold is moved to the fixed mold using the engaging portion as a fulcrum, the pivoting portion of the press plate and the bar as a force point, and the pivoting portion of the bar and the movable mold as a point of action. A mold clamping device configured to press against the mold.