JP3053235B2 - Press forming control method for plastic material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling press forming of a plastic material, and more particularly to a method of controlling a plastic material which is effective when an extreme eccentric load is generated as in the case of forming only one side in two-cavity forming. The present invention relates to a press forming control method.

[0002]

2. Description of the Related Art The present applicant has developed a hydraulic press forming apparatus in which equilibrium support devices are provided at four corners of a bed for press forming plastic materials such as SMC and FRP. Normally, the mold is arranged symmetrically between the bed and the slide so as to prevent eccentric load from being generated, but press molding is performed by attaching the mold to only one side of the bed or slide. In some cases, it must be done.

Conventionally, when such an extreme eccentric load occurs, for example, as disclosed in Japanese Patent Application Laid-Open No. Hei 1-266999.
Based on the high pressure side of the pair of left and right pressure cylinders disposed in the crown portion, the follow-up control is performed in accordance with the supporting force of the equilibrium support device below, and the position control of the low pressure side of the pressure cylinder is performed. Was what it was.

[0004]

However, pressurization on the low pressure side
The cylinder can support the support pressure setting of the equilibrium support device
Not, the low pressure side of the pressure cylinder - not only those position control in both equilibrium support device, or a gap between its apart slides equilibrium supporting device of the low-pressure side, one
Abnormal pressure was applied to the equilibrium support device.

[0005] For this reason, it is possible to increase the output of the equilibrium support device to cope with it .
Is then, I device Do largely becomes high titer, rather be preferred, easily even when extreme eccentric load is generated, and
There has been a demand for effective press forming.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and in order to solve the above problems, equilibrium support devices are provided at four corners of a bed of a press forming apparatus. In the press-forming control method of a plastic material, the plastic material to be loaded into the mold is controlled to be equilibrium-pressed with a slide via a pair of left and right pressure cylinders. During the descent of the pressurization by the slide that fluidly fills the cavity with the plastic material , the pressurization control of one of the left and right high pressure side pressurization cylinders is performed in accordance with the support pressure setting of the equilibrium support device below it. At the same time, the pressurizing cylinder on the low pressure side is pressurized and controlled in accordance with the supporting pressure of the equilibrium support device therebelow to support the slide in an equilibrium manner and descend, so that the plastic material in the mold cavity is lowered. the slide that you want to pressure curing During pressurization, the high-pressure side of the pressure cylinder - a balanced support device of the lower as well as pressure control while the pressure was controlled by setting a predetermined output of the low-pressure side of the pressure cylinder - about It is an object of the present invention to provide a press forming control method for a plastic material, wherein a slide is equilibrium supported by an equilibrium support device and press forming is performed while maintaining the same pressure control as described above.

[0007]

According to the present invention, the lowering of the pressurization during the press forming of the plastic material is performed by controlling the pair of left and right pressurizing cylinders by controlling the pressurizing pressure of the equilibrium support device according to the supporting pressure. By descending, the slide can follow and descend without leaving the balance support device. In addition, the pressure hardening during press forming of the plastic material is performed by setting the pressure cylinder on the high pressure side to a predetermined output to control the pressure of the equilibrium support device. By doing so, both the high-pressure side and the low-pressure side of the slide can reliably contact the equilibrium support device, and the plastic material can be pressed. Therefore, an extreme eccentric load can be dealt with without generating a gap or increasing the output of the balancing support device.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. FIG. 1 et seq. Are embodiments of the present invention. SMC and F
The press forming apparatus 1 of a plastic material such as RP is of a hydraulic press type. As shown in FIG. 1, a required rigid slide 5 is provided at a central portion surrounded by a crown 2, an upright 3, and a bed 4, and a crown 2 is formed. The pressurizing cylinder 6 is disposed symmetrically, and the pressurizing cylinder 6 is freely driven by a hydraulic servo pump 7 of a hydraulic pressure source (not shown), and the slide 5 is moved toward the lower bed 4 side. It is slidable.
A position detector 8 such as a linear scale is disposed on the side of the slide 5 so that the slide 5 can be press-formed by setting a program. On the lower surface of the slide 5 and the upper surface of the bed 4, an upper mold 9 and a lower mold 10 for press-molding required parts are arranged facing each other as shown in FIG. A sheet-shaped plastic material 12 such as SMC or FRP is loaded on a mold 10 and press-molded. Hydraulic support is provided at the four corners of the bed 4.
An equilibrium support device 14 in which leveling cylinders 13 such as bo cylinders are respectively provided is disposed, and the four corners of the lower surface of the slide 5 are equilibrium supported so that the slide 5 can be supported and controlled in equilibrium. Reference numeral 15 denotes a pressure detector for detecting a support pressure.

Normally, the above-mentioned control of the slide 5 by the equilibrium support device 14 is performed by leveling cylinders at four corners of the equilibrium support device 14 generated when the slide 5 is pressurized.
The support force, which is the reaction force of No. 13, is summed up via the pressure detector 15 and is compared with a predetermined reference register set value so that the support force is constant. In addition, the equilibrium support device 1
Reference numeral 4 indicates that the four leveling cylinders 13 follow and synchronize in response to the pulse oscillation by the set program.

Then, when the eccentric load of one side load is applied as shown in FIG.
Control by 4, to perform plastic material 1 and the slide pressing down flowing filling the cavity of the mold 11, pressure curing FIG. 2, respectively and in sliding pressure for, based on the hydraulic circuit diagram of FIG. 3 I have to.

That is, when the slide 5 is pressurized and lowered,
As shown in FIG. 2, the pressure detected by the pressure detector 15 of the leveling cylinder 13 is determined by the support pressure in accordance with the support pressure set value set in the equilibrium support device 14 which is controlled to descend by a predetermined program setting. The high-pressure side hydraulic servo pump 7 is transmitted to the setting controller 17 so as to control the high-pressure side pressurizing cylinder 6.

On the other hand, the low pressure side pressurizing cylinder 6 also has a pressure detector 1 connected to a leveling cylinder 13 thereunder.
The pressure detected in step 5 is transmitted to the controller 17 to control the low-pressure side servo pump 7 in the same manner as described above to control the pressurization in synchronization with the high-pressure side pressurizing cylinder 6. ing.

[0013] And sometimes pressurization at the slide to increase the pressure force of the slide 5 to pressure curing plastic material, pressurized to a predetermined pressure the bearing capacity of the leveling cylinders -13 balancing support device 14 as shown in FIG. 3 While controlling the support by pressing
The hydraulic circuit of the high-pressure side pressurizing cylinder 6 is connected to the pressure control valve 18 such as a proportional control valve, and the output of the high-pressure side pressurizing cylinder 6 is set to a predetermined pressure to control the output. I am trying to do it. Then, the pressurizing cylinder -6 on the low pressure side is press-controlled in the same manner as in the above-described slide pressurizing and descending, and press-formed in synchronization with the pressurizing cylinder -6 on the high pressure side. I have. The equilibrium support device 14 moves the four leveling cylinders 13 up and down in synchronization with each other in order to control the support force of the leveling cylinders 13 below the high pressure side pressurizing cylinders 6 to a predetermined pressure. Control. 19 is a servo pump for driving the equilibrium support device.

Therefore, even when a mold is attached to only one side of the bed and the slide and press-formed, the mold is installed on the high-pressure side of the slide and the slide is pressurized and lowered as described above. Also, the slide on the low pressure side can follow the balance support device without leaving. Therefore, even if an extreme eccentric load is applied, the plastic material can be easily and precisely press-formed into a predetermined shape without increasing the output of the equilibrium support device and increasing its size.

In the above embodiment, one side of the slide is on the high-pressure side and the other side is on the low-pressure side. In addition, the position control of the equilibrium support device can be appropriately performed according to the molding material, such as descending with a fixed curve or gradually descending stepwise.

[0016]

As described above, in the present invention, the slide to be pressurized by the pair of right and left pressurizing cylinders can be equilibrium supported by the equilibrium support device, so that the plastic material can be press-formed and the bed and slide can be formed. Even if the mold is installed on only one side and an extreme eccentric load occurs, slide
Pressurization descending in, nor during pressurization of pressure curing, a pair of left and right pressure cylinder - of the low-pressure side slide or away from the equilibrium support device, excessive without load, can be press-molded.
Then, since the balance support device and the slide are controlled in conjunction with each other, it is not necessary to increase the output of the balance support device to increase its size, and it is not necessary to increase the price of the device.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of one embodiment of the present invention,

FIG. 2 is an explanatory diagram of control during pressure lowering of the slide according to the first embodiment;

FIG. 3 is an explanatory view of control during pressurized curing of the slide.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Press-forming apparatus 4 ... Bed 5 ... Slide 6 ... Pressurizing cylinder 7 ... Servo pump 11 ...
Mold 12 ... Plastic material 14 ... Equilibrium support device

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsunori Takami 15-1, Minamifutami, Futami-cho, Akashi-shi, Hyogo Inside Kawasaki Yuko Co., Ltd. (72) Inventor Yukinobu Kawano 1-1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki (56) References JP-A-1-266999 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 43/32-43/42 B29C 43/58 B29C 33/20-33/24

Claims (1)

(57) [Claims] An equilibrium support device is provided at each of four corners of a bed of a press forming apparatus to control the slide to be equilibrium-supported, and a plastic material to be loaded into a mold is passed through a pair of left and right pressurizing cylinders. In the press-forming control method for plastic material, which is formed by pressing and equilibrating with a slide, the plastic material is filled into the cavity of the mold with a slide .
During the pressure lowering, one of the right and left high pressure side pressurizing cylinders is pressurized in accordance with the support pressure setting of the equilibrium support device therebelow, and the low pressure side pressurizing cylinder is controlled. -A slide that presses and controls the pressure corresponding to the support pressure of the equilibrium support device below it, supports the slide in equilibrium and descends, and pressurizes and hardens the plastic material in the mold cavity.
During pressurization, the pressure of the equilibrium support device below the pressurizing cylinder is controlled while setting and controlling the pressure of the high-pressure pressurizing cylinder to a predetermined output. A press-forming control method for a plastic material, characterized in that the press-forming is carried out while maintaining the same pressurization control as above, while supporting the slides in equilibrium with an equilibrium support device.