JPH0445280B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of pressing and molding plastic materials, and more particularly to a method of pressing and molding plastic materials that can compensate for excessive eccentric loads.

BACKGROUND ART Conventionally, in the press molding of plastic materials, an apparatus has been used in which a balance support device is disposed in the bed portion, and a slide is supported in balance so that the thickness of the molded product is uniformly press-formed.

Problems to be Solved by the Invention In the above-mentioned conventional press equipment with a balance support device, the leveling cylinder of the balance support device has a capacity of 25 tons, 50 tons,
Its maximum output is rated at 100 tons, etc., and it is designed to have sufficient compensation ability to cope with eccentric loads that occur during normal molding.

However, in 2-cavity or 4-cavity press forming, when forming only one side of the press molding, where an extreme eccentric load occurs, the leveling cylinder lacks capacity and an excessive eccentric moment acts. In conventional systems, the only way to cope with this problem was to increase the output of the leveling cylinder.

Means for Solving the Problems The present invention has been made in view of the above points, and in order to solve the above problems, a balance support device is provided at the corner of the bed of a press machine to balance the slide. This is a molding press method for plastic materials in which the plastic material loaded in the mold device is pressurized in an even manner. One or more pressurizing cylinders are arranged symmetrically in the crown part of the device, and plastic material is loaded only on either the left or right side of the 2-cavity or 4-cavity mold device. , the leveling cylinder of the balance support device arranged in the bed section, which performs follow-up control in synchronization with the side with the lower pressure force based on the side with the higher pressure force on either the left or right side of the pressurization cylinders arranged in a symmetrical manner. The supporting force is fed back to the side with the higher pressure of the pressure cylinders arranged symmetrically, and the plastic material charged to one side of the mold device is press-molded in synchronization with the pressure cylinders. An object of the present invention is to provide a method for forming and pressing a plastic material, which is characterized by the following steps.

Effects According to the present invention, when press-molding a plastic material, the other pressure cylinder is synchronously and follow-up controlled based on the side of the pressure cylinder disposed in the crown part that has a higher pressure force. In this way, the pressure cylinders are synchronously controlled, and the support force of the leveling cylinder of the balance support device of the bed section that supports the slide in balance is fed back to the side with the higher pressure of the left and right pressure cylinders, and the pressure is increased. control and synchronize the slide and leveling cylinder. Therefore, even if there is an eccentric load that exceeds the capacity of the leveling cylinder, such as when press forming on only one side of a 2-cavity or 4-cavity mold device, the left and right pressure cylinders are synchronized and balanced. Regardless of the magnitude of eccentric load, the slide can be maintained with a constant parallel accuracy and plastic materials can be molded.

Example Hereinafter, the present invention will be explained based on examples.

FIG. 1 and subsequent figures show an embodiment of the present invention. The press device 1 is a hydraulic press, and as shown in Fig. 1, a slide 5 of the required rigidity is installed in the center surrounded by a crown 2, an upright 3, and a bed 4, and two pressure cylinders 6 are installed in the crown 2. , 7 are fixed symmetrically, and the hydraulic servo pumps 9, 1 of the hydraulic source 8
0, the pressurizing cylinders 6 and 7 are freely driven, and the slide 5 is freely slidable toward the lower bed 4 side. Position detectors 11 and 12 such as linear scales are arranged on both sides of the slide 5 to detect the position of the slide 5 and to control the press. On the lower surface of the slide 5 and the upper surface of the bed 4, as shown in the figure, an upper mold 13 and a lower mold 16 with 2 or 4 molds are arranged facing each other for press-molding the required parts. A sheet-like plastic material 16 is loaded onto the lower mold 14 of this mold device 15 and molded.

On the other hand, a parallel support device 18 having leveling cylinders 17 such as hydraulic servo cylinders vertically disposed at each of the four corners of the bed 4 is arranged to support the four corners of the lower surface of the slide 5 in equilibrium, thereby supporting the slide 5. This allows precise horizontal control. The leveling cylinder 17 of the balance support device 18 is
1/3 to 5 for pressurized cylinders 6 and 7
Small output (100 tons, 200 tons, 400 tons in total)
ton), with a short stroke of 100 to 200 mm,
A required pressure detector 19 is connected and the support pressure is transmitted to the hydraulic servo pump 9, via the pressure position control device 20.
I try to give feedback to 10.

The pressure cylinders 6 and 7 are controlled by the control device 20 when the pressure of the leveling cylinder 17 detected by the pressure detector 19 is higher than the set speed of the leveling cylinder 17 set by the program, for example.
As shown in FIG. 2, a feedback signal is sent to the hydraulic servo pump 9 of the pressure cylinder 6 on the high pressure side to control the pressure cylinder 6 at low speed, and a synchronization signal is sent to the hydraulic servo pump 10 on the low pressure side. The pressure cylinder 7 on the low pressure side of the feed is synchronized with the pressure cylinder 6 on the high pressure side so that the slide 5 descends in equilibrium.

In this way, the pressure detected by the leveling cylinder 17 of the balance support device 18 is fed back to the higher pressure side of the pressure cylinders 6, 7, and the left and right pressure cylinders 6, 7 are adjusted to the higher pressure side. Using the other as a reference, the slide 5 is press-formed following the balance support device 18 in synchronization with the other.

Therefore, regardless of the magnitude of the eccentric load on the slide, the left and right pressurizing cylinders can be easily synchronized, and the slide can always be supported with a constant parallel accuracy. Moment can be made to have no effect.

Therefore, with 2-cavity or 4-cavity mold equipment,
Even if only one side is molded, press molding can be performed smoothly without excessive eccentric load, and damage to the mold device and insufficient capacity of the parallel support device can be avoided.

In addition, if there is one pressure cylinder on each side,
It is sufficient to compare them as described above, and if there are a plurality of left and right pressurizing cylinders, the total pressurizing force of the left and right pressurizing cylinders is compared and controlled as described above.

Other Embodiments FIG. 3 shows another embodiment of the present invention, in which the press device 1
The height adjusting rods 23 are freely protruded from the four corners of the lower surface of the slide 5 so as to be able to support the slide 5 in correspondence with the leveling cylinder 17, and the slide 5 is controlled as described above.

The height adjustment rod 23 has a square thread shape, and is screwed onto the slide 5 as shown in the figure, and connected to the spline joint 2.
4 to an elevating drive device 26 using a gear mechanism 25 or the like, and the amount of protrusion can be freely adjusted from 50 to 500 mm.

In this embodiment, the die height of the slide can be easily adjusted according to the size of the mold device, and as described above, without causing excessive eccentric load.
It can be press-molded.

In this way, the present invention can be implemented in a manner compatible with various types of press equipment.

Although the above embodiments have been described with respect to plastic materials, the invention can be similarly applied to plastic materials containing reinforcing materials such as SMC.

Effects of the Invention As described above, in the present invention, when press-forming is performed by loading plastic material only on one side of a two-cavity or four-cavity mold device, an excessive eccentric load is likely to occur on the slide. Nevertheless, it is possible to easily synchronize and control the pressure cylinders on the left and right sides based on the side with the higher pressure force, and the slide can be smoothly moved without excessive eccentric load. You can press by lowering the slide. In addition, if plastic material is loaded only on one side of a two-cavity or four-cavity mold device and press-formed, an excessive eccentric moment will act on the balance support device, which normally has a small output, resulting in insufficient capacity. Although it is easy to damage the mold equipment, etc., the supporting force of the leveling cylinder of the balance support device can be fed back to the side with the higher pressure of the pressure cylinder mentioned above, and the descending speed and pressure of the pressure cylinder can be controlled. can. Therefore, an excessive eccentric moment is not applied to the balance support device, and even with a small output, it is possible to avoid the lack of capacity, and it is possible to press-form plastic materials with a uniform thickness. be.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of an embodiment of the present invention, Fig. 2 is a block diagram of the slide synchronization control same as above, and Fig. 3 is a height adjustment rod of the slide die height of another embodiment of the above, with some parts omitted. FIG. 1... Press device, 2... Crown, 4... Bed, 5... Slide, 6, 7... Pressure cylinder, 13... Mold device, 16... Plastic material, 17... Leveling cylinder, 18... Balance support device.

Claims (1)

[Scope of Claims] 1. Molding of plastic material, in which a balance support device is disposed at the corner of the bed of a press device to support the slide in balance, and the plastic material loaded into the mold device is pressurized and molded in a balanced manner. A pressing method, in which one or more pressurizing cylinders are arranged in a symmetrical manner in the crown part of the press device corresponding to a mold device having two or four molds symmetrically, The plastic material is loaded only on either the left or right side of the 2-cavity or 4-cavity mold device, and the pressure cylinders arranged symmetrically are placed on either the left or right side, which has a higher pressure force. As a reference, follow-up control is carried out in synchronization with the side with lower pressing force, and the supporting force of the leveling cylinder of the balance support device installed in the bed section is adjusted to the side with the higher pressing force of the pressurizing cylinders arranged symmetrically above. A press method for molding plastic material, characterized in that the plastic material charged on one side of a mold device is press-molded in synchronization with a pressurizing cylinder based on feedback from the pressurizing cylinder.