JP3053234B2 - Pressure molding method of resin molding press - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure molding method for a resin molding press such as an SMC or FRP, and more particularly, to a preset final clamping position even when the hardness changes due to a difference in molding material lots. The present invention relates to a pressure molding method of a resin molding press capable of press molding by pressurizing to a maximum.

[0002]

2. Description of the Related Art Conventionally, in an FRP press molding apparatus, a mold closing pressure, which greatly affects the shapeability and surface quality of a molded product, has been set to a constant value.

[0003]

Therefore, when a material having a low viscosity is mixed, excessive burrs are generated, and when a material having a high viscosity is mixed, underfilling occurs or surface gloss is deteriorated. Or Therefore, each time, the pressure must be finely adjusted and press-formed while checking the material hardness, so that productivity cannot be increased.

[0004] Also, Japanese Patent Application Laid-Open No. 1-156020 discloses a method.
How to control the hydraulic press
Multi-stage pressure from the time of filling to the pressure according to the state of the resin
Is known to control over the cavity
Detects the resin pressure inside and performs the measurement according to the detected pressure.
Molding without excessive or insufficient pressure in the stage
Thus, the pressure control becomes complicated.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and in order to solve the above problems, an upper mold and a lower mold are installed on a slide and a bed of a press molding apparatus. Then, in a pressure molding method of a resin molding press that press-molds a resin material such as SMC or FRP, a required allowable range is provided as a final clamping position of the press pressure,
Within this predetermined allowable range, the pressing force of the slide and the mold clamping position
And set the slides with the specified press output.
Pressing the mold and allowing the final mold clamping position described above
After reaching the range, the relationship between the above-mentioned pressing force and the mold clamping position
The pressure of the pressurizing cylinder according to the
An object of the present invention is to provide a pressure molding method for a resin molding press, wherein the pressure molding is performed within a predetermined range which is gradually increased and decreased within an enclosure.

[0006]

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 for resin molding such as RP is a hydraulic press type, and as shown in FIG.
A slide 5 having a required rigidity is provided in a central portion surrounded by the bed 4. Then, three pressurizing cylinders 6 are juxtaposed in the crown 2 and the pressurizing cylinder 6 is driven by the hydraulic servo pump 7 serving as a hydraulic pressure source, so that the slide 5 can slide toward the lower bed 4. And An upper die 8 and a lower die 9 are respectively arranged on the lower surface of the slide 5 and the upper surface of the bed 4 so as to face each other as shown in the figure. A molding material 11 such as a composite resin such as SMC or FRP or an engineering resin is mounted and press-molded.

The above-described pressurizing circuit 12 of the pressurizing cylinder 6
1 is connected with a pressure detector 13 as shown in FIG. 1 and a pressure control valve 14 such as a proportional control valve is connected so that the pressurizing cylinder 6 can be pressurized and controlled based on a predetermined program setting. ing. Reference numeral 15 denotes a hydraulic tank.

A position detector 15 such as a linear scale is attached to the side of the slide 5 at least at the position where the mold 10 is closed. The pressure start position and the final mold clamping position of pressurization can be set variably.

The final clamping position of the above pressurization is set to a required tolerance so that even if the lots of the molding material 11 are different, or even if the same lot has different viscosities due to different storage times, it is possible to cope with them. The position is controlled by providing a range. Therefore, the pressurizing force of the pressurizing cylinder 6 is set fluidly by providing a required adjustment width corresponding to the allowable range of the mold clamping position as shown in FIG. The position is within the allowable range.

This will be described with reference to the flowchart of FIG. In the present invention, the press press control described above can be selected, and a press start position at a predetermined upper position from the mold origin is set when starting the press of this control (or a set value input in advance). 3), and the flow of FIG.
Like the chart, the press output, its adjustment width, the final mold clamping position and its allowable range are set. The allowable range can be appropriately set, for example, to 0.5%, 1%, 2%, 5%, etc., corresponding to the molded product.

Then, the molding material 11 is mounted on the lower mold 9 of the mold 10, and the slide 5 is lowered to clamp the mold.
The pressurization is started at the set pressurization start position, and the mold clamping position of the mold 9 is detected by the position detector 15 and the press output by the pressurizing cylinder 6 is detected by the pressure detector 13. And FIG.
If the mold clamping position does not reach the set allowable range of the final mold clamping position, the pressure of the pressurizing cylinder -6 is set to a predetermined value based on the mold position and the output relationship shown in FIG. And within the allowable range of the final mold clamping position, the pressurizing force of the pressurizing cylinder 6 is also sequentially increased within the predetermined allowable range based on the relationship of FIG. It is reduced, and press forming is performed within a set predetermined range.

[0012] Therefore, even if the viscosity of the molding material is different, it can be press-pressed with flexibility and can be flow-filled without forming a cavity in a predetermined cavity of the mold or extruding the molding material. Good molded product can be molded. Also, when the viscosity of the molding material is hard or soft as in the past, there is no need to fine-tune the press output while checking the material strength each time, and press molding can be performed automatically, greatly increasing productivity. be able to.

In the above embodiment, the slide without the balance support device for balancing the slide is described. However, the slide with the balance support device can be similarly applied. Further, the relationship between the mold clamping position and the press output is not limited to the one proportional to the linear shape as shown in FIG. 2, but may be an exponential function or a step-like one. It is preferable that the origin of the mold is set by sliding the entire load in the actual mold clamping state on the bed or bed, taking into account the influence of the frame distortion of the apparatus.

[0014]

As described above, in the present invention, the mold is
Reached the allowable range of the final clamping position of press press
Later, according to the relationship between the pressing force and the mold clamping position described above
Increasing or decreasing the pressure of the pressurized cylinder within the specified tolerance
Press forming within the specified range set by the mold.
In this way, even if the viscosity of the molding material varies and differs ,
The Oite press output can with a predetermined allowable range, over
The molding material can be reliably flow-filled into a predetermined cavity of the mold without applying a large load, and press molding can be performed. For this reason, or missing meat, flash does not or occur, luster without inferior, Ru can be press-molding a good molded product quality
That can be automatically pressurized with flexibility,
As usual, the viscosity of the molding material is hard or soft
Press each time while checking the material strength.
No need to fine-tune the output and press forming can be performed automatically
Productivity can be greatly increased.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a press forming apparatus according to one embodiment of the present invention,

FIG. 2 is a diagram showing a relationship between a mold clamping position and a press output according to the first embodiment;

FIG. 3 is a flowchart for controlling mold clamping according to the first embodiment;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Press-forming apparatus 4 ... Bed 5 ... Slide 6 ... Pressure cylinder 8 ... Upper mold 9 ... Lower mold 10 ... Mold 13 ... Pressure detector 14 ...
Pressure control valve 15 ... Position detector

Continuation of the front page (72) Inventor Yukinobu Kono 1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries Inside the Akashi Factory (56) References JP-A-1-156020 (JP, A) JP-A-58- 16814 (JP, A) JP-A-1-156023 (JP, A) JP-A-1-292500 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 43/36-43 / 42 B29C 43/58 B29C 33/20-33/24

Claims (1)

(57) [Claims] 1. A pressure forming method of a resin forming press in which an upper die and a lower die are installed on a slide and a bed of a press forming apparatus, and a resin material such as SMC or FRP is press-formed. provided with the required tolerance as a clamping position of the final pressurization of the slide in the predetermined allowable range
Set the relationship between the force and the mold clamping position, and
The slide is pressurized with the output and the mold
After reaching the allowable range of the mold clamping position,
Pressurizing the pressurizing cylinder according to the relationship with the mold clamping position
Where the force is gradually increased or decreased within the specified tolerance and set
A pressure molding method for a resin molding press, characterized by performing press molding within a predetermined range .