JP3603161B2 - Drilling method of perforated plate for aircraft engine nacelle sound absorbing panel - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for punching a perforated plate for an aircraft engine nacelle sound absorbing panel.
[0002]
[Prior art]
2. Description of the Related Art In an aircraft, a honeycomb sandwich structure having a sound absorbing performance called a sound absorbing panel is used in a portion called an engine nacelle that covers an engine in order to prevent noise generated by the engine. As the face plate of the honeycomb sandwich structure, a perforated plate having a large number of holes has been used, and this perforated plate has conventionally been made of an aluminum alloy. This perforated plate made of aluminum alloy is manufactured by punching, drilling, or the like, followed by press forming, stretch forming, burson forming, or the like into an engine nacelle shape.
[0003]
By the way, when the airfield has been in the seafront area or in the case of aircraft that flies frequently on the sea, engines often receive winds containing a lot of salt, and corrosion of metal engine nacelles due to salt damage has been regarded as a problem. Was. Therefore, in recent years, a composite engine nacelle has been developed instead of metal (aluminum alloy) for the purpose of weight reduction and improvement of corrosion resistance. However, the process of manufacturing a composite perforated plate is difficult, so far it has been difficult to form a composite material into a nacelle shape and harden it by drilling (still mainstream in the world), plastics with a large number of drilling pins A method has been adopted in which a pin plate made of a porous material is stabbed in a composite material before curing and then heated and cured. Recently, uncured composite material (prepreg) has been preheated until the resin flow deteriorates, and then punched in a flat plate state by punching, and then formed into a curved mold. A method of heat curing is also introduced. (Japanese Patent Laid-Open No. Hei 10-128778)
[0004]
However, the method of drilling the composite material into a nacelle shape after hardening it into a nacelle shape is time-consuming and expensive. If the shape of the molded product is a three-dimensional contour product, it is difficult to process, and an NC control drill machine is required. The introduction and maintenance of the system will be very difficult. In addition, a method in which a plastic pin plate is pierced with a pre-cured composite material and then heat-cured to form a perforated plate requires that the pin plate be manufactured in accordance with a three-dimensional contour. And costly. Furthermore, a method in which the prepreg is preheated, punched in a flat plate state with a punch, and then formed into a curved surface forming die and heat-cured is performed in such a manner that the entire prepreg becomes hard and has no adhesive force, and is formed into a curved surface forming die and attached. Becomes difficult.
[0005]
[Problems to be solved by the invention]
Therefore, the present invention does not have the problems of the prior art described above, and can perform drilling accurately, at high speed, and easily with a simple device configuration, and heat is not applied only around the holes at the time of drilling. Aircraft engine nacelle sound-absorbing panel that can keep the entire prepreg in a soft and sticky state, and also prevent the resin of the prepreg from flowing into the drilled holes during heat curing to prevent clogging of the holes It is intended to provide a method for perforating a perforated plate for use.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a method of perforating a perforated plate for an aircraft engine nacelle sound-absorbing panel according to the present invention is a method in which an uncured fiber reinforced resin prepreg face plate is provided with a blade having a number of holes subjected to ultrasonic vibration or heat. Drilling is performed while the resin in the prepreg around the hole is semi-cured with a cutting tool or laser.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of a method for perforating a perforated panel for an aircraft engine nacelle sound absorbing panel according to the present invention will be described. Drilling is performed while semi-curing the material. The means for drilling is any of a cutting tool with ultrasonic vibration, a cutting tool with heat, and a laser. In the following, the respective drilling methods by these drilling means will be described with reference to the drawings. A method of drilling with a cutting tool to which ultrasonic vibration is added will be described. As shown in FIG. 1, an uncured fiber reinforced resin prepreg sheet material 1 is cut into a required size to form a face plate 2. Laminate the number. Next, the laminated uncured fiber reinforced resin prepreg face plate 2 was sandwiched and fixed between the upper prepreg press plate 4 having a large number of holes 3 and the lower receiving blade / prepreg press plate 5 as shown in FIG. Thereafter, when the blade 7 to which the ultrasonic vibration is applied by the ultrasonic transmission horn 6 is lowered by the press machine 8, the blade 7 of the blade 7 in contact with the uncured fiber reinforced resin prepreg face plate 2 as shown in FIG. Acoustic frictional heat is generated, and by the shearing action between the cutting edge and the receiving blade and prepreg press plate 5 in this state, a hole 9 is formed in the face plate 2 as shown in FIG. As a result, the area around the hole is heated, and the resin in the prepreg around the hole is semi-cured. Therefore, the resin in the prepreg does not flow into the bore 9 in the prepreg curing step in the subsequent autoclave. In addition, the obtained laminated uncured fiber resin prepreg porous face plate 10 is soft and has an adhesive force. Then, the prepreg 11 which is removed by the perforation as shown in FIG. 3C is sucked by the vacuum pump 12 shown in FIG.
[0008]
Explaining a method of making a hole by using a blade to which heat is applied. As shown in FIG. 1, an uncured fiber reinforced resin prepreg sheet material 1 is cut into a required size to form a face plate 2, and a required number of face plates 2 are laminated. Next, the laminated uncured fiber reinforced resin prepreg face plate 2 was fixed by being sandwiched between an upper prepreg press plate 4 having a large number of holes 3 and a lower receiving blade / prepreg press plate 5 as shown in FIG. Thereafter, when the blade 15 heated by the heater 14 is lowered by the press 16, when the blade 9 of the blade 15 and the receiving blade and prepreg press plate 5 are sheared, the hole 9 is formed in the face plate 2 in the same manner as described above. At the same time, the periphery of the hole is heated by the heat of the cutting tool 15, and the resin in the prepreg around the hole is semi-cured. Therefore, the resin in the prepreg does not flow into the bore 9 in the prepreg curing step in the subsequent autoclave. Moreover, the obtained laminated uncured fiber reinforced resin prepreg porous face plate 10 is soft and has an adhesive strength. The prepreg extracted by the perforation is sucked by the vacuum pump 12 and stored in the tank 13.
[0009]
The above two drilling methods are excellent in manufacturability, particularly in that many holes can be processed simultaneously. The blade 7 to which ultrasonic vibration is added and the heated blade 15 in these drilling methods are both punching blades, and the circular cutting edge has a thin blade shape in cross section as shown in FIG. Although it moves up and down, it may be replaced with a cutting blade for cutting shown in FIG. As shown in FIG. 7A, an uncured fiber reinforced resin prepreg face plate 2 is arranged between a hollow lower blade 17 made of carbide and an upper receiving table (push cutting table) 18 made of aluminum. After applying ultrasonic vibration to the receiving table (push-off table) 18 or heating this receiving table (push-off table) 18, the receiving table (push-off table) 18 is lowered as shown in FIG. The face plate 2 is pressed against the hollow lower blade 17 to form the hole 9 and, at the same time, the area around the hole is heated by the ultrasonic frictional heat of the receiving table (push-off table) 18 or the heat of the heated receiving table (push-off table) 18. Then, the resin in the prepreg around the hole is semi-cured. Therefore, the resin in the prepreg does not flow into the opened holes 9, and the obtained laminated uncured fiber-reinforced resin prepreg porous face plate 10 is soft and has an adhesive force. The prepreg 11 removed by the perforation is sucked by the vacuum pump and stored in the tank in the same manner as described above.
[0010]
The method of drilling by laser will be described. As shown in FIG. 1, an uncured resin prepreg strip 1 is cut into a required size to form a face plate 2, and a required number of face plates 2 are laminated according to a part drawing. Next, as shown in FIG. 8, a large number of holes 9 are sequentially formed in the laminated uncured fiber reinforced resin prepreg face plate 2 by thermal processing with a laser 19, and at the same time, the area around the holes is heated to remove the resin in the prepreg around the holes. Semi-cured. Therefore, the resin in the prepreg does not flow into the bore 9 in the prepreg curing step in the subsequent autoclave. Moreover, the obtained laminated uncured fiber reinforced resin prepreg porous face plate 10 is soft and has an adhesive strength. The prepreg extracted by the perforation is sucked by the vacuum pump and stored in the tank in the same manner as described above.
[0011]
As shown in FIG. 9B, a large number of holes 9 are formed in the uncured fiber reinforced resin prepreg face plate 2 of a required size in a planar state by laminating a required number of sheets as shown in FIG. to produce a porous plate for an aircraft engine nacelle acoustical panel by punching the laminated uncured prepregs porous faceplate 10 while semi-curing the resin in the prepreg around the hole, first product layer uncured fiber-reinforced resin prepreg porous The face plate 10 is shaped and affixed to a curved mold 20 as shown in FIG. 9c, and then covered with a release film 21 having a high elongation as shown in FIG. 9d. Cover film 22 is attached to the periphery of the curved surface forming mold 20 via a sealing material 23, and then the inside of the bag film 22 is evacuated to remove the release film 21 and the bag film 22. The pressure is applied to the laminated uncured fiber reinforced resin prepreg perforated face plate 10 by a pressure difference, and then the entire curved surface forming mold 20 is put into an autoclave 24 shown in FIG. Thus, a perforated plate 25 for an aircraft engine nacelle sound-absorbing panel having a curved surface shape shown in FIG.
[0012]
Drilling method drilling the laminated uncured fiber-reinforced resin prepreg porous surface plate 10 by the present invention is a resin only to a higher temperature is applied in the prepreg of the part bore around the large number of holes 9 hardened been semi-cured Therefore, the resin in the prepreg does not flow into the hole 9 during the curing of the prepreg in the autoclave 24, and the size and shape of the hole 9 are maintained. Moreover, since the laminated uncured fiber reinforced resin prepreg porous face plate 10 as a whole is flexible and has an adhesive force, it is very easy to mold and attach it to the curved mold 20. Further, the mold release film 21 is covered thereover, a bag film 22 is further covered thereover, the seal is evacuated with a sealant 23, and then the curved surface forming mold 20 is put into an autoclave 24, and heated and pressurized. When cured, the resin in the prepreg does not flow into the holes 9 and does not close the holes 9, so that the aircraft engine nacelle sound-absorbing panel perforated plate 22 having a curved shape with high dimensions and accuracy can be easily obtained.
[0013]
【The invention's effect】
As can be understood from the above description, the method of perforating a perforated plate for an aircraft engine nacelle sound absorbing panel of the present invention is based on the uncured fiber reinforced resin prepreg face plate, in which a number of holes are subjected to ultrasonic vibration or a blade, or heat is added. Drilling is performed while the resin in the prepreg around the hole is semi-cured with a cutting tool or laser, so the resin in the prepreg flows into the drilled hole in the subsequent prepreg curing process in an autoclave. However, the size and shape of the hole are maintained. In addition, the obtained uncured fiber reinforced resin prepreg porous face plate is flexible and retains adhesive strength as a whole because heat is applied only around the holes. And, since the above-mentioned hole making method makes holes in the uncured fiber reinforced resin prepreg face plate in a flat state, a large number of holes can be accurately and rapidly formed in the uncured fiber reinforced resin prepreg face plate with a simple device configuration. Moreover, the holes can be easily formed.
[0014]
Further, uncured fiber-reinforced resin prepreg porous surface plate obtained by punching method of an aircraft engine nacelle acoustical panel perforated plate of the present invention has a flexible and adhesive force as a whole, adhered to shaping the curve mold It is very easy to do, and after putting it in an autoclave together with the curved mold after the evacuation process with a bag film and curing by heating and pressing, the resin in the prepreg does not flow into the holes and closes the holes. Therefore, it is possible to easily obtain a perforated plate for an aircraft engine nacelle sound absorbing panel having a curved shape with high dimensions and accuracy.
[Brief description of the drawings]
FIG. 1 is a view showing a state in which an uncured fiber reinforced resin prepreg strip is cut into required dimensions to obtain a face plate.
FIG. 2 is a diagram illustrating a method for punching a perforated panel for an aircraft engine nacelle sound absorbing panel according to the present invention, in which a required number of uncured fiber reinforced resin prepreg face plates obtained in FIG. FIG.
3 (a) to 3 (c) are views showing a process of perforating an uncured fiber reinforced resin prepreg face plate by the perforation method of FIG. 2;
FIG. 4 shows another example of the method of perforating a perforated panel for an aircraft engine nacelle sound absorbing panel of the present invention in which a required number of uncured fiber reinforced resin prepreg face plates obtained in FIG. It is a figure showing one.
5 shows a cross-sectional shape of a cutting tool used in the drilling method shown in FIGS. 2 and 4, wherein a is a perspective view and b is a cross-sectional view.
FIG. 6 is a view showing a cutting tool for pressing in place of the cutting tool in FIGS. 2 and 4;
7 (a) and 7 (b) are views showing a step of punching holes in an uncured fiber-reinforced resin prepreg face plate by the cutting blade for cutting in FIG. 6;
FIG. 8 is a view showing still another method of perforating the perforated plate for an aircraft engine nacelle sound absorbing panel of the present invention, which perforates the uncured fiber reinforced resin prepreg face plate obtained in FIG. 1 by laser.
[9] a~f On that made by drilling the drilling process laminating uncured fiber-reinforced resin prepreg porous faceplate of the present invention, showing a process of manufacturing the aircraft engine nacelle acoustical panel perforated plate It is.
[Explanation of symbols]
Reference Signs List 1 Uncured fiber reinforced resin prepreg sheet material 2 Uncured fiber reinforced resin prepreg face plate 3 Hole in holding plate 4 Upper prepreg holding plate 5 Lower receiving blade and prepreg holding plate 6 Ultrasonic transmission horn 7 Ultrasonic vibration added Cutting tool 8 Press machine 9 Hole in face plate 10 Laminated uncured fiber reinforced resin prepreg Porous face plate 11 Prepreg removed by drilling 12 Vacuum pump 13 Tank for storing prepreg removed by drilling 14 Heater 15 Heated cutting tool 16 Pressing machine 17 Hollow Lower blade 18 Receiving table (push cutting table)
19 laser 20 curved surface forming die 21 release film 22 bag film 23 sealing material 24 autoclave

Claims (1)

On the uncured fiber reinforced resin prepreg face plate, drill holes while semi-curing the resin in the prepreg around the holes with a blade tool with ultrasonic vibration added, a blade tool with heat applied, or a laser. A method for perforating a perforated plate for an aircraft engine nacelle sound-absorbing panel.

Images