JPH0354895Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a press molding apparatus for plastic sheet materials.

Prior Art In recent years, press forming using plastic sheet materials such as SMC has been put into practical use, and with the automation of factories, plastic sheet materials are automatically fed into press forming equipment and press forming is performed unattended.

Problems that the invention aims to solve However, even if the plastic sheet material is loaded onto a conveyor, transported onto a mold, and then dropped, it is a flexible and highly viscous material, so it is difficult to maintain the mold. It was easy to deviate greatly from the predetermined mounting position.

Therefore, when the slide of the press molding device is lowered to close the mold, the slide becomes eccentric and tilts, resulting in defective products being molded, and the molding surface of the mold being scratched and damaged. had to be replaced.

Furthermore, since the plastic sheet material expands or contracts due to thermal reactions, it has been difficult to follow and support the slide without leaving it on the counterbalance support device.

Means for Solving the Problems The present invention was developed in view of the above-mentioned points, and includes disposing a counterbalance support device in the bed portion of the press molding device and supporting the slide in a counterbalance manner with the counterbalance support device. In a press-forming machine for plastic sheet materials, such as SMC, which is automatically fed into a mold machine and press-formed, a pressure detector is installed in the balance support device to detect the supporting force. When the supporting force detected by the pressure detector increases by about 3 to 4%, the balance support device is lowered in steps of 0.01 to 0.1 mm to support the slide in the balance, and the press forming device is lowered. Proximity switch mounting bases are provided on the upright parts facing the four corners of the slide, and proximity switches are mounted on the proximity switch mounting bases facing the slide so that fluctuations in the tilt of the slide can be detected. When the slide is placed into the mold with an abnormal deviation, the slide is lowered to close the mold device and before applying pressure, a proximity switch detects the shake due to the abnormal tilt of the slide and issues an alarm, etc., and presses. An object of the present invention is to provide a press molding device for a plastic sheet material, characterized in that the molding device is configured to be stopped.

Effects According to the present invention, even if the plastic sheet material is automatically fed into the press molding machine in an unattended state and the plastic sheet material deviates significantly from the predetermined position of the mold, if the slide is eccentric and tilted by a predetermined amount, the This can be detected by proximity switches placed opposite the four corners of the mold, preventing defective products from being press-molded, and automatically stopping the press-forming equipment before the mold is pressurized and closed. Damage to the mold can be prevented.

In addition, when the supporting force detected by the pressure detector of the balance support device increases by about 3 to 4%, the balance support device is increased by 0.01%.
By controlling the descent sequentially in steps of ~0.1mm,
Not only resin materials with a large amount of shrinkage, but also a wide variety of resin materials, can be supported evenly without having to separate the slide from the support device, ensuring that there are no voids in the molded product, and that there are no sink marks or unevenness on the outer surface. It is possible to press mold beautiful molded products.

Example The present invention will be explained below based on examples.

FIG. 1 and subsequent figures show an embodiment of the present invention. The press forming device 1 is a hydraulic press, and as shown in FIGS. 1 and 2, a slide 5 of required rigidity is provided in the center surrounded by a crown 2, an upright 3, and a bed 4.
A pressurizing cylinder 6 fixedly attached to the crown 2 is freely driven by a hydraulic servo pump (not shown) as a hydraulic source, so that the slide 5 can freely slide toward the lower bed 4 side. On the lower surface of the slide 5 and the upper surface of the bed 4, a mold device 9, which is formed as a pair of an upper mold 7 and a lower mold 8 for press-molding required parts such as automobile parts, is mounted facing each other. A plastic sheet material 10 such as an SMC material placed on a material feeding device such as an endless conveyor (not shown) is dropped and loaded onto the lower mold 8 of the mold device 9 in accordance with the press molding cycle. I have to. The descending part of the slide 5 with the minimum and maximum die height for press molding of this press molding device 1 has the following characteristics:
A proximity switch mounting base 11 is attached to the side surface of the upright 3 as shown in FIGS. 1 to 3, and a slide 5 slides into sliding guide 12 fixed to a corner of the upright 3 as shown in FIG. A proximity switch 14 is installed on the proximity switch mounting base 11 facing the side of the gib 13, and the slide 5 is 0.8
When the slide 5 tilts by ~1.0 mm, one of the proximity switches 14 is actuated to sound an alarm 15 attached to the side of the upright 3, and the slide 5 is either stopped as it is or raised and stopped.

In addition, counterbalance supports such as hydraulic servo cylinders, which have a small output of 1/2 to 1/5 of that of the pressure cylinder 6 and require a short stroke range, are installed opposite the four corners of the slide 4. The devices 16 are respectively installed vertically on the bed 4, and the side ends of the slides 5 are supported in a balanced manner so that the slides 5 can be controlled to descend with high accuracy while being synchronized. A required pressure detector 17 is connected to this equilibrium support device 16, and in the previous step of fluidly filling a cavity 18 formed by closing the plastic sheet material 10 with a mold device 9, a fourth pressure sensor 17 is connected. As shown in the figure, the supporting force detected by the balance support device 16 is compared with the reference setting force of the reference register 19 set in the program using the comparator 20 and controlled appropriately, so that the slide 5 is not moved away from the balance support device 16. I'm trying to follow. In the post-process in which the plastic sheet material 10 is filled into the cavity 18 and undergoes a thermal reaction to cause contraction, the slide 5 is applied with a constant predetermined pressing force, and the supporting force of the equilibrium support device 16 is increased as shown in FIG. The supporting force is calculated from 3% to 4% through the supporting force register 21 and the supporting force comparator 22.
0.001~0.1mm
The lowering of the plastic sheet material 10 is controlled sequentially for each time, so that the plastic sheet material 10 is finally filled into a predetermined cavity 18 and press-molded. Although not shown, the mold device 9 is equipped with a steam or electric heating device to control the heating of the mold device 9 to a predetermined temperature to cause a reaction in the plastic sheet material 10 to be loaded. It is something that

Therefore, the pressurizing cylinder 6, the balance support device 1
The standard setting values of speed, position, supporting force, etc. of 6 are programmed in advance, and the plastic sheet material 10 is placed in the lower mold from the material feeding device while the upper mold 7, which is molded for automotive parts, for example, is raised. If the slide 5 falls onto the mold and deviates considerably from the predetermined position as shown in FIG. Lean. Side part of slide 5 is 0.8mm
When the slide 5 is tilted more than this, at least one of the proximity switches 14 facing the side of the slide 5 is activated at the position of the descending portion of the slide 5, and a signal is sent to the alarm 15 to issue an alarm, and the descent of the slide 5 is stopped. Then, it will rise and stop.

Therefore, even if the plastic sheet material is thrown into the mold device out of position during unmanned press molding, if the slide is significantly eccentric, it will automatically stop, preventing defective products from being press molded or the mold This prevents the inner surface of the device from being scratched and damaged.

In particular, in this embodiment, since the proximity switches are arranged on the same plane at the corner of the side surface on the short side of the slide, the purpose can be achieved with the minimum number of four switches, but it is not necessary. Accordingly, an appropriate number of proximity switches can be installed on the long side of the slide, above the descending portion of the slide, etc. so as to freely detect the inclination of the slide.

In addition, when the plastic sheet material is normally mounted on the mold device, if the supporting force detected by the pressure detector of the balance support device increases by about 3 to 4%, the balance support device will be increased by 0.01 to 0.1 mm. A molded product of a predetermined shape can be press-molded by sequentially lowering the pressure and applying pressure for a certain period of time until reaction hardening is completed. Therefore, it is possible to mold beautiful molded products with no voids and no sink marks or irregularities on the outer surface, not only for resin materials with large shrinkage amounts but also for a wide variety of resin materials, as well as shorten molding time. This eliminates the need for trial and error in press control, allowing smooth press forming.

The proximity switch mounting base can also be mounted so that it can be moved vertically depending on the mold dimensions, and the proximity switch can also be mounted on the slide side to adjust the inclination of the slide through the upright side. It is also possible to repurpose it so that it can be detected.

Effects of the invention As described above, with the present invention, even if the plastic sheet material is introduced into the mold device of the press molding device with a considerable deviation in position during unmanned press operation, it can be positioned facing the four corners of the slide. The provided proximity switch can detect abnormal inclination of the slide, thereby preventing the press molding of defective products and preventing the slide from inclining and damaging the inner surface of the mold device.

In addition, when the supporting force detected by the pressure detector of the balance support device increases by about 3 to 4%, the balance support device is increased by 0.01%.
By controlling the descent sequentially in steps of ~0.1mm,
Not only resin materials with a large amount of shrinkage, but also a wide variety of resin materials, can be supported evenly without having to separate the slide from the support device, ensuring that there are no voids in the molded product, and that there are no sink marks or unevenness on the outer surface. Beautiful molded products are produced by press molding.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted schematic front view of an embodiment of the present invention, FIG. 2 is a schematic cross-sectional view for explaining the arrangement of the proximity switch of the same as the above, and FIG. Figure 4 is a block diagram of the same slide support. 1...Press molding equipment, 3...Upright,
5...Slide, 9...Mold device, 10...Plastic sheet material, 11...Proximity switch mounting base, 1
4...Proximity switch, 15...Alarm.

Claims (1)

[Scope of Claim for Utility Model Registration] A flat support device is provided in the bed of the press molding device so that the slide is supported by the flat support device, and a plastic sheet material such as SMC is placed in the mold device. In a press-forming machine for automatically feeding and press-forming plastic sheet materials, a pressure detector is installed in the balance support device to detect the supporting force, and the supporting force detected by this pressure sensor is approximately 3 to 4%. Increase the balance support device by 0.01
The slides are arranged so as to be lowered sequentially at ~0.1 mm intervals to support the slides evenly. Proximity switch mounting bases are installed on the upright parts facing the four corners of the lowered slides of the press forming equipment, and the slides are Proximity switches are installed on the proximity switch mounts facing the slides so that tilt deflection can be detected, and when the plastic sheet material is thrown into the mold with an abnormal deviation, the slides are lowered and the mold device is activated. 1. A press molding device for plastic sheet material, characterized in that the press molding device is configured to detect vibration due to an abnormal inclination of the slide with a proximity switch and issue an alarm or the like to stop the press molding device before applying pressure in a closed state.