JPH06134282A - Control of fan of autoclave - Google Patents

Abstract

PURPOSE:To obtain a molded product of high quality by controlling the number of rotations of a fan so as to set the same to the rated current value of a motor corresponding to the load change due to the pressure fluctuations of an autoclave to smoothly circulate the gas in a pressure container. CONSTITUTION:In an autoclave wherein a molding material l is pressed and heated in a pressure container A equipped with a fan motor 20 circulating gas to be molded, when load is fluctuated by pressure fluctuations in a speed increasing stage, the current value of the fan motor 20 is compared with the set currant value of the motor 20 by a fan speed control means I and, when the load becomes excessive, the output frequency of an inverter 31 is lowered to decrease a speed and, when the current value of the motor 20 is smaller than the set current value, the output frequency of the inverter is raised to increase a speed and controlled so that the current value of the motor 20 always becomes the set current value thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a fiber reinforced plastic (FR) used for aircraft, space equipment, industrial equipment and the like.
P) a laminated structure or component, a multilayer printed wiring board used as an electronic device component, a molding material such as a laminated glass or a composite material for building materials, which is heated under pressure in an autoclave to mold a fan for circulating a gas. It is about how to control.

[0002]

2. Description of the Related Art Conventionally, as a technique for controlling a fan that circulates gas in an autoclave, there has been a practice of using a full-practice Sho 63-1765.
The one described in Japanese Patent No. 33 is known.

In this technique, in an autoclave in which a high-pressure gas introduced into a closed pressure vessel is heated and circulated and convected by a circulation fan, the rotation speed of a motor for rotating the circulation fan is determined by the pressure in the pressure vessel. Inverter control is performed so as to decrease as the temperature rises. However, the conventional inverter only holds the frequency at the time of overload in the acceleration stage and does not have a lowering function,
Since the lowering function does not work until the maximum set speed (frequency) is once reached, if a pressure load is applied thereafter, it will be cut off due to overcurrent. Therefore, under the present circumstances, the fan is operated by pressurizing it after reaching the maximum set speed with a low load.

[0004]

However, in the conventional inverter, when the inverter is started in a pressurized state due to power failure, emergency stop, etc., the overload protection function is activated and it is not possible to cope with further pressure increase, and the inverter is overloaded. The load cutoff function operates, the motor stops, and the function of the entire device must be stopped. Here, with the overload protection function, as shown in FIG.
It is a function that sets an overload protection level (current limit level) so that the current does not exceed the rated current of the motor, and when it reaches the overload protection level, it accelerates and stops to prevent overload cutoff. Further, as shown in FIG. 7, the overload cutoff function is a function of stopping the output of the inverter and stopping the motor to protect the inverter when the overload protection function does not operate.

The present invention was developed for the purpose of solving the above-mentioned problems.

[0006]

As shown in FIGS. 1 to 7, the present invention relates to an autoclave in which a molding material 1 is heated under pressure and molded in a pressure vessel A equipped with a fan motor 20 for circulating a gas. When the load fluctuates due to pressure fluctuation in the speed-up stage, the current value of the fan motor 20 is compared with the set current value of the motor, and if overloaded, the output frequency of the inverter 31 is reduced to decelerate, If it is smaller than the value, the output frequency of the inverter 31 is increased to increase the speed and the frequency is controlled so as to always be the set current value of the motor.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an example of an autoclave molding apparatus for carrying out the present invention will be described. Autoclave molding equipment
As shown in FIGS. 2 and 3, a pressure container A including a container body 2 for accommodating the molding material 1 and a door 2a for sealing the container 2.
A pressurizing means B for supplying high pressure gas into the pressure vessel A to pressurize the molding material 1, a heating and cooling means C for heating and cooling the high pressure gas supplied into the pressure vessel A, and the molding material A depressurizing means D for depressurizing the inside of the vacuum bag 18 for sealing 1 to a high vacuum and a fan 2 for the heated or cooled gas.
Gas circulation means E for circulating air into the wind tunnel 6a from the outer ventilation passage 6b formed between the inner wall 2b of the container and the wind tunnel wall 5 by means of 2 and the change in the pressure of the gas circulated by the gas circulation means E. Accordingly, the fan speed control means I controls the rotation speed of the fan while maintaining the motor set current accordingly.

Next, the details of each means will be described. As shown in FIGS. 2 and 3, the pressure vessel A has a door 2a for sealing the vessel body 2 and a rail 4 for guiding the carriage 3 laid in the vessel body 2.

As shown in FIG. 2, the pressurizing means B is provided so that gases such as high-pressure nitrogen gas, high-pressure carbon dioxide gas, high-pressure air, etc. can be supplied from the high-pressure gas supply source 7 via the automatic valve 8. The gas is heated or cooled via the heater 10 and the heat exchanger 11. Then, it is exhausted through the automatic valve 9.

As shown in FIG. 2, the heating / cooling means C is a second carriage in which a heater 10 and a heat exchanger 11 (used as a cooler in this case) are mounted on a rail 4 in the rear part of the pressure vessel A. 12 is provided, and the gas body is heated or cooled by the heater 10 and the heat exchanger 11. Then, the pressure vessel is penetrated through the automatic valve 13 to communicate with the heat exchanger 11 to supply cooling water, and the lower portion of the pressure vessel A is communicated from below the heat exchanger 11 and is cooled via the automatic valve 14. It is provided so that the used water can be discharged. As another example of the heating / cooling means, the heating medium may be heated and cooled outside the pressure vessel, and the heating medium may be used to heat and cool the gas body through a heat exchanger. It is not limited to the example.

The depressurizing means D, as shown in FIGS.
A vacuum pump 15 installed outside the pressure vessel A communicates with the inside of the pressure vessel A through an automatic valve 16 and is connected to the inside of the pressure vessel A. At the tip of the piping, as shown in FIG. The vacuum joint is detachably attached to the vacuum joint 17b which is airtightly held and joined via a jig 19 which is communicated from the inside of the vacuum bag 18. Then, by operating the vacuum pump 15, the inside of the vacuum bag 18 in which the molding material 1 is covered and sealed is decompressed via the automatic valve 16 to a high vacuum. Depending on the molding material, this depressurizing means may be unnecessary, and the present invention is not limited to this embodiment.

As shown in FIGS. 2 and 3, the gas circulating means E is provided with a small container (small pressure container) 21 having a motor 20 therein in a sealable manner at the rear part of the pressure container A and at the inside of the rear part of the pressure container A. A fan drive mechanism F including a fan 22 fitted and fixed to a motor shaft 20a that is protruded in
The temperature detector 23 for detecting the temperature of the gas in the small container 21 and the detection signal thereof are transmitted to the automatic valve 24 to transmit the small container 2
A motor cooling mechanism G for cooling and controlling the motor 20 in 1 below an allowable temperature, and a double ventilation passage (outside ventilation) formed by a cylindrical thin-plate wind tunnel wall 5 along the inner wall 2b of the container body 2. It is composed of a passage 6b and a circulation mechanism H that forms a wind tunnel 6a), and the gas supplied into the pressure vessel A is blown by the fan 22 and passes through the outer ventilation passage 6b to swirl with the guide vanes 30 and at the door inner wall 2c. It is constructed so that it can be inverted and circulated into the wind tunnel 6a. As another embodiment of the gas circulation means, for example, as shown in FIG. 4, the gas is shielded by the fan 22 from the outside ventilation passage 25 by the door shielding plate, and the gas is directed downward to the lattice plate at the lower portion of the pressure vessel A. 26, the molding material 1 may be passed upward, the porous plate 28 may be passed from the inside of the wind tunnel 27, and the fan 22 may be circulated from the upper part of the partition plate 29 to the lower part via the heating / cooling means C. The pressure vessel may be a vertical gas circulation means, and the present invention is not limited to the difference in the configuration of the gas circulation means. Further, as another embodiment of the fan drive mechanism, a motor is installed at a rear external position of the pressure vessel A, and a shaft portion of the motor is projected into the pressure vessel A through a sealing mechanism, and a shaft tip portion of the motor is provided. An air blower fan may be fitted into and fixed to the fan, and is not limited to the embodiment of the present invention.

The fan speed control means I, as shown in FIG. 1, connects the fan motor 20 with a conventional inverter 31 and detects a load current of the motor, and a current detector 32.
A comparator 34 that compares the current detected by the current detector with a set current in a setter 33, a converter 35 that is compared in the comparator and converts the difference into an acceleration or deceleration signal, and the conversion Current generator 36 whose output current value changes according to the signal of the generator, and a closed loop circuit configured to transmit the frequency setting signal (for example, 4 to 20 mA DC) generated by the variable current generator to the inverter and increase or decrease the frequency. It was done. Then, as shown in FIG. 1, the load current value of the fan motor, which changes according to the increase or decrease of the pressure, is compared with the set current value of the motor. As shown by the dotted lines in FIGS. When the output frequency of the fan motor 20 is lower than the set current value, the output frequency of the inverter 31 is increased to control the frequency so that the motor 20 always has the set current value. It is designed to operate at the rated current value).

Next, the operation will be described. First, in the preparatory stage, the molding material 1 is housed in the pressure container A shown in FIGS. 2 and 3, and the depressurizing means D depressurizes the inside of the vacuum bag 18 to complete the preparation for molding.

Next, the pressurizing means B shown in FIG. 2 is operated to supply the high-pressure gas into the pressure vessel A and the fan drive mechanism F is operated to indicate the high-pressure gas by a solid arrow in FIG. As described above, after the gas flow passing through the outer ventilation passage 6b and flowing out from the outer ventilation passage is made into a swirling flow by the guide vanes 30, it is reversed by the inner wall 2c of the door facing the swirling flow, and the reversal flow is generated in the wind tunnel 6a. The heater 1 swirling and flowing through the pressure vessel A
0, sucked into the fan 22 via the heat exchanger 11,
The gas is circulated by the fan 22.

Then, the molding is performed by pressurizing and heating according to a molding pattern as shown in FIG. 5, and this molding pattern gradually increases the pressure, maintains a constant pressure at a predetermined pressure, and further increases the pressure. The pressure is increased, and when the pressure reaches a predetermined pressure, the pressure is maintained for a certain period of time, and then the pressure is reduced. Therefore, the fan motor 2 that changes depending on the increase and decrease in pressure
The load current value of 0 is compared with the set current value of the motor 20 shown in FIG. 1, and if overloaded, the output frequency of the inverter 31 is reduced to decelerate. If it is smaller than the set current value, the output frequency of the inverter 31 is changed. By increasing the speed to increase the speed and controlling the frequency so that the set current value of the motor 20 is constantly maintained,
As indicated by the dotted line in FIG. 6, the frequency of the motor 20 of the fan 22 corresponds to the frequency according to the change in pressure and does not cause overload, that is, the control level without reaching the overload cutoff level shown in FIG. Is driven.

Next, in the cooling stage, the pressure is reduced and cooled in accordance with the molding pattern shown in FIG. 5, but when the current is constant, the frequency characteristic with respect to changes in pressure decreases as shown in FIG. Therefore, although the frequency increases and the rotation speed of the motor 20 of the fan also increases, the fan is operated at the set current value (the rated current value of the motor) without being overloaded. Then, the molding of the molded material 1 is completed, the door 2a is opened, and the molded material 1
Is completed and one step is completed.

[0018]

Since the present invention is constructed as described above, the frequency is constantly controlled so that the motor rated current value set by detecting the load current of the fan motor is set.
The load fluctuation due to the pressure fluctuation of the autoclave can be coped with, and the fan motor can be always operated at the motor rated current value without stopping, and the gas circulation is smoothly performed. As a result, a high-quality molded product having good moldability can be obtained.

[Brief description of drawings]

FIG. 1 shows an example of a block diagram of fan speed control means in an autoclave for carrying out the present invention.

FIG. 2 is a partially cutaway schematic side view of an autoclave molding apparatus for carrying out the present invention.

FIG. 3 is a schematic front view of the autoclave molding apparatus as viewed in the direction of arrow XX in FIG.

FIG. 4 is a partially cutaway schematic side view showing another embodiment of the gas circulating means for carrying out the present invention.

FIG. 5 shows an example of a molding pattern of an autoclave for carrying out the present invention.

FIG. 6 shows frequency characteristics with respect to pressure of the fan speed control means for carrying out the present invention.

FIG. 7 shows a motor current characteristic with respect to a load in which the function of the present invention is added to the function of a conventional inverter.

[Explanation of symbols]

 A pressure vessel B pressurizing means C heating / cooling means D depressurizing means E gas circulation means F fan drive mechanism G motor cooling mechanism H circulation mechanism I fan speed control means 1 molding material 2 container body 2a door 2b container inner wall 2c door inner wall 3 trucks 4 rail 5 wind tunnel wall 6a wind tunnel 6b outside ventilation passage 7 high pressure gas supply source 8 automatic valve 9 automatic valve 10 heater 11 heat exchanger 12 second truck 13 automatic valve 14 automatic valve 15 vacuum pump 16 automatic valve 17a vacuum joint 17b vacuum joint 18 Vacuum Bag 19 Jig 20 Motor 20a Motor Shaft 21 Small Container 22 Fan 23 Temperature Detector 24 Automatic Valve 25 Outer Ventilation Path 26 Lattice Plate 27 Wind Tunnel 28 Perforated Plate 29 Partition Plate 30 Guide Blade 31 Inverter 32 Current Detector 33 Setter 34 comparator 35 converter 36 variable current generator

Claims (1)

[Claims] 1. An autoclave in which a molding material is pressurized and heated in a pressure vessel equipped with a fan motor that circulates gas and is molded, when the load fluctuates due to pressure fluctuation in the acceleration stage, the current value of the fan motor is changed. Compared with the set current value of the motor,
If it becomes overloaded, the inverter output frequency is reduced to decelerate, and if it is smaller than the set current value, the inverter output frequency is raised to increase the speed and the frequency is controlled so that it always becomes the motor set current value. Characteristic autoclave fan control method.