JPH0121778B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to setting a mold closing position in a mold clamping device used for injection compression molding, injection foam molding, and the like.

In injection compression molding, injection foam molding, etc.
It is necessary to control the closing position of the mold in two stages.

Japanese Patent Publication No. 55-6054 discloses a method of adjustment by providing wedges that move forward and backward in the mold part as this two-stage control means, but it is difficult to accurately adjust the wedges provided on the left and right sides, and the The structure of the mold part was also complicated, making it unsuitable for foam molding, which increases the cavity volume after filling with synthetic resin is completed.

In addition, Japanese Patent Publication No. 57-22009 discloses an injection compression molding method using a toggle direct pressure mold clamping device, but it uses a mold whose parting surface is sealed by the force of a spring. As a clamping device, a piston is fixed to the tie bar to move the mold clamping cylinder each time, and the tie bar is equipped with a stopper to limit the amount of retraction of the mold clamping cylinder. First, even if a chain or the like is used to rotate the stoppers at the same time, it is difficult to precisely align the positions of the plurality of stoppers, and the device is also complicated.

This invention was devised to solve the above-mentioned conventional drawbacks, and its purpose is to control the retracted position of the mold clamping ram by a simple means, and operate the mold clamping ram based on this control. This new configuration enables two-stage control of the mold closing position, displays the set position of the mold clamping ram, and can be used for both injection compression molding and injection foam molding, which have different mold closing orders. An object of the present invention is to provide a mold closing position setting device.

A feature of the present invention for the above-mentioned purpose is that the mold clamping device includes a toggle mechanism that moves a movable platen forward and backward relative to a fixed platen, and a mold clamping cylinder that pressurizes the movable platen through the toggle mechanism. An adjustment shaft made of a hollow screw shaft is screwed into the center of the rear end so that it can move forward and backward, so that the inner end can freely approach and separate from the rear end of the mold clamping ram. The core is inserted through the core, and a scale is provided on the side of the core to indicate the position of the mold clamping ram. The closed position can be set in two stages.

The present invention will be explained in detail below using illustrated examples.

In the figure, 1 and 2 are fixed plates placed on the machine base 3 with a required interval, and 4 is a movable plate, which is inserted through multiple tie bars 5 and 5 provided across both fixed plates 1 and 2. Molds 6 and 7 are attached to opposing surfaces of the movable platen 4 and one fixed platen 2, respectively.

8 is a hydraulically operated mold clamping cylinder installed on the other fixed platen 1, and the movable platen 4 and mold clamping ram 9 are connected via a toggle mechanism 10.

A cylindrical bearing member 11 with a threaded inner circumferential surface is inserted through the center of the rear end of the mold clamping cylinder 8, and an adjustment shaft 12 made of a hollow threaded shaft is mounted on the bearing member 11. It is screwed in so that it can move forward and backward depending on the movement.

The inner end of this adjustment shaft 12 passes through the rear end of the mold clamping cylinder 8 and faces the rear end of the mold clamping ram 9 so as to be able to approach and separate from the rear end, and the outer end protruding from the bearing member 11 has a handle. A member 13 is attached.

A core 14 integrally connected to the rear end of the mold clamping ram 9 is inserted into the adjustment shaft 12.
A nut member 15 with a handle is screwed onto the outer periphery of the shaft bearing member 11 and is in contact with the end face of the bearing member 11 to lock the adjusting shaft 12 in a predetermined position.

On the side surface of the core 14, a scale 16 indicating the set position of the mold clamping ram 9 is provided in the axial direction, and on the end surface of the handle member 13 of the adjustment shaft 12, the scale 16 is provided along with the scale 16 in the axial direction. With a baseline,
A scale 17 that can indicate the rotation angle of the adjustment shaft 12 is provided radially.

The scales 16 are provided at equal intervals (for example, 1 mm) in the axial direction, with the zero point being the position where the inner end of the adjustment shaft 12 touches the rear end surface of the mold clamping ram 9.
The distance S between the rear end and the inner end of the adjustment shaft 12 can be read from these scales.
Furthermore, the scale 17 is created by dividing the circumference into equal parts (for example, 100 equal parts) in consideration of the screw pitch (for example, 2 mm) of the adjustment shaft 12, and the rotation angle of the adjustment shaft 12 can be read from the scale. It is becoming possible to do this.

Next, the setting of the mold closing position will be explained.

First, the toggle mechanism 10 is extended to move the movable platen 4 toward the fixed platen 2, and the molds 6 and 7 are closed to determine a first mold closing position. Next, the adjustment shaft 12 is rotated so that its inner end abuts against the rear end of the mold clamping ram 9, which is always in a fixed position in the mold closed state. Due to this contact, the scale 16 formed on the core 14 becomes a zero indication on the end face where the scale 17 is formed.

Once the closed positions of the molds 6 and 7 have been set as described above, the second mold closed position is set. This setting is made by rotating the adjustment shaft 12 and moving it outward to separate the abutting inner end from the rear end of the mold clamping ram to a predetermined point,
Further, the setting is completed by fixing the nut member 15 to the bearing member 11. Further, the distance S caused by the movement is displayed on the scale 17.
As a result, as shown in FIG. 3, the mold clamping ram 9 can be retracted by hydraulic pressure until its rear end contacts the inner end of the adjustment shaft 12, and at the same time, the movable platen 4 is also retracted and one mold 7 is separated from the first mold closing position by a dimension equal to the above-mentioned distance S, and a second mold closing position is set.

The operation of the mold clamping device after setting the two mold closing positions described above differs depending on the injection molding performed there. In the case of injection compression molding, since the molten resin filled in the mold must be compressed by the mold, the positions of the molds 6 and 7 closed by the toggle mechanism 10 are set in a preset second position. The mold is in the closed position, and then the mold clamping ram 9 is moved forward, and the mold is strongly compressed together with the movable platen 4 to the first closed position. After cooling, the mold is forcefully opened again to the second closed position, and then the mold is opened by the toggle mechanism 10.

Moreover, in the case of injection foam molding, contrary to the above, since the molten resin filled in the mold must be foamed and expanded, the molds 6 and 7 are closed by the toggle mechanism 10 by the first closing. position, injection and filling of molten resin is performed under strong mold clamping by the mold clamping ram 9, and then the mold clamping ram 9 is moved backward together with the movable platen 4, or the mold is moved to the second closed position by resin pressure. The mold 7 is moved to perform foam molding.

In any case, the retraction of the movable platen 4 during molding is limited to a preset distance S between the mold clamping ram 9 and the adjustment shaft 12, and as long as the distance S is set accurately, The mold closing position can be controlled in two stages without requiring any special means.

As described above, in this invention, the adjustment shaft 12 is screwed into the center of the rear end of the mold clamping cylinder 8 so that it can move forward and backward, so that it faces the rear end of the mold clamping ram 9 so as to be able to approach and separate from it. A core 14 integral with the mold clamping ram 9 is inserted through the mold clamping ram 9, and the retreating position of the mold clamping ram is adjusted by rotating the adjustment shaft, thereby setting the closing position of the mold, which is opened and closed by a toggle mechanism, in two stages. Therefore, it is possible to accurately set the closing position of the mold corresponding to the amount of compression, the amount of foaming, etc. in the mold. Moreover, shaft member 1
Since the scale 16 that displays the set position is provided on the side of the mold, it is possible to read the distance between the first and second closed positions of the mold, and the setting accuracy is further improved. It is also possible to prevent distortion and sink marks from occurring. Furthermore, the device itself is extremely simple, as all you need to do is insert an adjustment shaft and a shaft member with a scale into the center of the rear end of the mold clamping cylinder, and there are few failures, and no special skills are required for setting operations. It has features such as:

[Brief explanation of drawings]

The drawings show one embodiment of the mold closing device according to the present invention, and FIG. 1 is a partially vertical side view when the mold is clamped;
Figure 2 is an outer end view of the mold clamping cylinder, Figure 3 is the second
FIG. 3 is a partial vertical cross-sectional view of the main parts for explaining the setting of the mold closing position. 1, 2... Fixed plate, 2... Movable plate, 6, 7...
Mold, 8...Mold clamping cylinder, 9...Mold clamping ram, 1
0... Toggle mechanism, 11... Bearing member, 12...
Adjustment shaft, 13...handle member, 14...core,
16...Scale.

Claims (1)

[Claims] 1. In a mold clamping device having a toggle mechanism that moves a movable platen forward and backward relative to a fixed platen, and a mold clamping cylinder that pressurizes the movable platen via the toggle mechanism, a hollow The adjustment shaft is screwed in so that it can move forward and backward, so that the inner end faces the rear end of the mold clamping ram so that it can move toward and away from it, and the core integrated with the mold clamping ram is inserted into the adjustment shaft, and the core integrated with the mold clamping ram is inserted into the adjustment shaft. A mold closing position setting device for a mold clamping device, characterized in that a scale is provided on the side surface of the core to indicate the position of a mold clamping ram.