JPH0360646B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a molding device for thermosetting resin materials, and is capable of constantly performing molding operations under optimal conditions, sometimes in immediate response to the progress of the molding process. It is related to the technology that can be used.

[Prior art and its problems]

Conventionally, thermosetting resin materials have been molded based on predetermined standard molding temperatures and molding times. However, when actually molding a thermosetting resin material, due to variations in the composition ratio of each component that makes up the thermosetting resin material and changes in the viscosity of the thermosetting resin material due to changes in outside temperature, etc. The optimum forming temperature and the preset standard forming temperature sometimes do not match, and the standard forming time sometimes results in too much forming time or too little forming time.
Therefore, conventionally, in order to correct excessive or insufficient molding time, the molded product obtained was analyzed and the set value of the molding temperature or molding time was corrected. However, because it is not possible to accurately grasp the gelation time and curing time by analyzing the molded product obtained, it is not possible to quickly correct the optimum molding temperature or time, which has the disadvantage of lowering the yield. Ta.

[Means for solving problems and their effects]

In order to eliminate the drawbacks of the prior art, the present inventor has repeatedly conducted numerous experiments and has determined that the thermal expansion phenomenon during gelling and the contraction phenomenon during curing of a thermosetting resin material can be interpreted as a displacement phenomenon of a movable mold. The present invention was completed based on this finding.

The solution adopted in the present invention is
The pressing force of the movable mold against the fixed mold and the repulsive force due to fluctuations in the internal pressure of the cavity due to thermal expansion during the gelling stage and contraction during the curing stage of the thermosetting resin material filled in the cavity. A movable mold operating means configured to allow the movable mold to move forward and backward while maintaining balance, a displacement detection device for detecting the movement displacement of the movable mold, and a differential calculation based on the detected value of the displacement detection device. A calculation device that performs calculations including calculations to obtain the gelation time and curing time of a thermosetting resin material, and a comparison of the gelation time and curing time obtained with the calculation device with the standard gelation time and curing time, and the deviation thereof. It is constructed with a heating and cooling control device that controls the rise and fall of the mold temperature during subsequent molding operations based on the signal.

According to the above solution, it is possible to immediately and continuously detect the state of molding progress of the thermosetting resin in the mold during compression molding. In addition, it is possible to adjust the mold temperature and molding time in response to the molding progress status, and molding operations can always be performed under optimal conditions.
This can dramatically improve the yield of molded products.

〔Example〕

Hereinafter, the present invention will be explained based on embodiments shown in the drawings. FIGS. 1A and 1B are sectional views of essential parts showing an embodiment of a molding apparatus for thermosetting resin materials according to the present invention. The molding apparatus 1 is a pressure molding type molding apparatus, in which a male fixed mold 3 is attached to a fixed platen 2, and a female movable mold 5 is mounted on a vertically movable movable plate 4. It is fixed. The movable platen 4 is connected to an output end 6a of a movable mold operating means 6, such as a hydraulic cylinder, and is configured to move up and down in response to the output of the movable mold operating means 6. . The movable mold operating means 6 clamps the movable mold 5 to the fixed mold 3 at a predetermined pressure by, for example, suppressing a hydraulic cylinder to a constant pressure, and also controls the thermosetting resin material in the mold cavity. The structure is such that fluctuations in the repulsive force generated by expansion and contraction of the movable mold 8 act on the movable mold 5, and the movable mold 5 can be moved forward or backward relative to the fixed mold 3. The movable mold 5 is provided with spacers 7, 7 for adjusting the molding thickness.

The movable platen 4 includes a detector 9 of a displacement detection device 9.
a is installed. The detector 9a employs a differential transformer method or the like, and detects the displacement of the movable platen 4 that moves in a proportional state in conjunction with the movable mold 5, and detects the displacement of the movable mold 5 with respect to the fixed mold 3. Configured for indirect detection. Although not shown, it is of course possible to adopt a structure in which the displacement of the movable mold 5 with respect to the fixed mold 3 is directly detected. The detection signal a of the detector 9a is processed by a displacement meter 9b, as shown in FIG. 2, and the displacement of the movable mold 5 is displayed and output in an appropriate manner. The output signal b from the displacement meter 9b is transmitted to the recorder 10 and the calculation device 1.
1.

The arithmetic device 11 is composed of a microcomputer, etc., and is equipped with an arithmetic processing circuit that differentiates the input signal b, performs differentiation processing to obtain the displacement speed of the movable mold 5, and performs calculations based on the displacement speed and the amount of displacement. Thus, the elapsed time of the displacement period is obtained. In this way, the thermosetting resin material 8 can be made into a gel (from ○A to ○H) according to the outflow stop time ○A, the curing start time ○C, and the curing end time ○D, which will be described later (see FIG. 3). curing time CT (elapsed time from ○A to ○D) can be obtained.

The arithmetic unit 11 also functions to set the mold temperature to the optimum condition during subsequent molding. That is, while comparing the gelation time GT and curing time CT obtained by the differentiation with the preset standard gelation time and curing time, it is determined that the obtained gelation time GT and curing time CT are longer than the corresponding standard times. When the time is short, a temperature reduction signal e is outputted to the mold heating/cooling control device 14 to appropriately lower the temperature of the molds 3 and 5, and conversely, the gelling time and curing time obtained are longer than the corresponding standard time. Sometimes the mold 3,
The heating/cooling controller 14 is provided with a comparison circuit that outputs a temperature increase signal f for appropriately increasing the temperature of the heating/cooling control device 14.
The output frequency of the signals e and f outputted from the arithmetic unit 11 to the heating/cooling control device 14 is not limited to each time the thermosetting resin material 8 is molded, but may vary depending on the number of times of molding (for example, 5 times). ),
It may be output at a rate of once. The heating/cooling control device 14 outputs the temperature decreasing signal e or the temperature increasing signal f.
Accordingly, the heat source (for example, electricity, heat medium oil, etc.) of the molds 3 and 5 is adjusted as appropriate to adjust the mold temperature to an appropriate heating temperature. in short,
Depending on the time, gelation time GT and curing time CT
It is checked whether the molding time conforms to each standard time, and if a deviation occurs, the mold temperature for subsequent molding is corrected to an appropriate value.

A signal c from the arithmetic device 11 indicating the hardening end time is input to the elevation control device 12. The lift control device 12 is configured to appropriately process the signal c and then output it to the hydraulic unit 13 as a signal d for lowering the hydraulic cylinder, which is the operating means 6 for the movable mold.

Note that the molding apparatus for thermosetting resin materials according to the present invention is not limited to the compression molding method shown in FIGS. Any molding method may be used as long as the molding apparatus is equipped with the movable mold operating means 6 and the displacement detection device 9 as described above.

Next, the effects of the thermosetting resin material molding apparatus according to the present invention will be explained. First, a predetermined amount of thermosetting resin material 8 is poured into the recess 5a of the movable mold 5 in the lowered state.
(hereinafter referred to as material 8) is placed. Next, the movable mold operating means 6 is operated to raise the movable mold 5 and pressurize the material 8. When the material 8 is pressurized in the cavity 15 as shown in FIG.
It flows out from the pinch-off part 16 which has a clearance of about 0.1 mm. When the material 8 hardens in the pinch-off section 16, the material 8 from the pinch-off section 16
The material 8 in the cavity 15 is thermally expanded due to the heating of the molds 3 and 5. Back pressure generated by the thermal expansion of the material 8 acts on the movable mold 5, which is clamped at a predetermined pressure, and the pressing force of the movable mold 5 and the internal pressure of the material 8 drop to a balanced position. . The amount of displacement of the movable mold 5 due to the lowering is successively detected by the displacement detection device 9. After the thermal expansion of the material 8 disappears and the material 8 becomes a gel, hardening of the material 8 begins. Then, the movable mold 5 rises as the material 8 hardens and contracts. Movable mold 5 accompanying the rise
The amount of displacement is sequentially detected by the displacement detection device 9. When the displacement amount of the movable mold 5 successively detected by the displacement detection device 9 is output to the recorder 10,
For example, it is obtained as a displacement-time curve A as shown in FIG. In the figure, ○A corresponds to the time when the material 8 stops flowing out from the cavity 15, ○B corresponds to the time when the thermal expansion of the material 8 ends, ○C corresponds to the hardening start time, and ○D corresponds to the hardening end time. In this way, by detecting the displacement of the movable mold 5 with the displacement detection device 9, the material 8
The progress of molding can be detected.

The signal c from the arithmetic unit 11 that informs the curing end time ○2 is processed by the lifting control device 12 to add a post-processing time HT such as a necessary gloss increase time, and then lowers the movable mold operating means 6. A signal d is output to the hydraulic unit 13 to operate the movable mold operating means 6 to lower the movable mold 5. Once the mold is opened, the molded product is removed by appropriate means. The gloss increase time is defined as the gloss increase time when the material 8 is SMC (Sheet Mold
Compound), etc., it refers to the heating holding time after the end of curing required for the surface gloss of the cured molded product to reach the specified gloss (Gloss 90 in the case shown in the figure).

Note that when the gelling time GT and curing time CT obtained by the calculation device 11 are shorter than the corresponding standard times, the heating and cooling control device 14 sends a signal e to appropriately lower the temperature of the molds 3 and 5 during subsequent molding. The heating temperature of the molds 3 and 5 is corrected and adjusted so that they reach the optimum heating temperature. Conversely, the obtained gelation time GT
When the curing time CT is longer than the corresponding standard time, a signal f for appropriately increasing the temperature of the molds 3 and 5 is output to the heating/cooling control device 14 so that the molds 3 and 5 reach the optimum heating temperature. Adjust the correction accordingly. In this way, the mold temperature during molding is prevented from inadvertently deviating from the optimum conditions.

The inventor conducted an experiment under the following conditions and obtained the results shown in FIG.

(1) Thermosetting resin material Type SMC Constitutively unsaturated polyester resin 80 parts Low shrinkage agent 20 parts Calcium carbonate 100 parts Curing agent 1 part Mold release agent 3 parts Thickener 1 part Glass fiber 80 parts (2) Molding conditions Gold Mold temperature fixed mold 135℃ Movable mold 145℃ SMC charge amount 350g Shape of molded product 200×220×4.5mm Pressure force 50Kgf/cm ² (3) Gloss measurement method Measuring device Gloss Meter GM−26 Light receiving area 12× 20mm 60° [Effects of the Invention] As detailed above, the present invention has the following excellent effects.

(1) Since the displacement detection device can instantly and continuously detect the molding progress of thermosetting resin materials, it is possible to easily control the quality of each molded product, and also to Temperature control and molding time control can be easily performed, and yield can be improved.

(2) The mold temperature can be sequentially controlled while comparing the actual gelling time and curing time with the standard gelling time and curing time, so the mold temperature can be instantly adjusted to the optimum temperature. This makes it possible to improve yield.

[Brief explanation of drawings]

1A and 1B are cross-sectional views showing main parts of an embodiment of a molding apparatus for thermosetting resin materials according to the present invention;
The figure is a circuit diagram showing an embodiment of the thermosetting resin material molding apparatus according to the present invention, and FIG. 3 is a graph showing the progress of molding the thermosetting resin material. 3... Fixed mold, 5... Movable mold, 6... Operating means for movable mold, 8... Thermosetting resin material, 9...
...Detection device, 11...Arithmetic device, 14...Heating and cooling control device.

Claims (1)

[Claims] 1. Balance between the pressing force of the movable mold against the fixed mold and the repulsive force due to fluctuations in the pressure inside the cavity caused by thermal expansion during the gelling stage and contraction during the curing stage of the thermosetting resin material filled in the cavity. a movable mold operating means configured to allow the movable mold to move forward and backward while maintaining the movable mold; a displacement detection device for detecting the movement displacement of the movable mold; and a differential calculation based on the detected value of the displacement detection device. A calculation device that performs calculations to obtain the gelation time and curing time of a thermosetting resin material, and a deviation signal for comparing the gelation time and curing time obtained by the calculation device with the standard gelation time and curing time. 1. A molding device for thermosetting resin material, comprising a heating and cooling control device that controls the temperature of the mold during subsequent molding operations based on the above.