JP2014168821A - Cutting method of fiber-reinforced plastic plate reinforced by high strength fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further lengthen the service life of a trimming die, by efficiently processing in an accurate shape, while preventing a crack of the fracture edge and a crack with the lapse of time by the inexpensive trimming die.SOLUTION: A method is provided for cutting a fiber-reinforced plastic plate reinforced by embedding high strength fiber composed of any of carbon fiber, Kevler fiber, PBO fiber, super- strength polyethylene fiber and high-strength polyarylate fiber, and forms a fracture plate 11 in a predetermined shape by a grinding process after a fracture process of forming the fiber-reinforced plastic plate 10 as the fracture plate 11 of a predetermined shape by fracturing the plate in a linear shape. The fracture process punches the fiber-reinforced plastic plate 10 as the fracture plate 11 having a grinding margin 16 on the fracture edge 11A by fracturing the fiber-reinforced plastic plate 10 by a trimming die 3 by pressing the trimming die 3 to a surface of the fiber-reinforced plastic plate 10 placed on a cutting surface 2 of a pedestal 1. The grinding process adjusts the cutting edge 11B of the fracture plate 11 into a predetermined shape by grinding the grinding margin 16 of the fracture plate 11 which is subjected to punching by the fracture process.

Description

  The present invention relates to a cutting method for cutting a fiber-reinforced plastic plate in which high-strength fibers are reinforced by embedding them in plastic into a predetermined shape. In particular, the present invention does not relate to a method of cutting a fiber-reinforced plastic plate reinforced with a fiber that can be cut with a conventional blade such as glass fiber, and is considered to be extremely difficult to cut with a blade. The present invention relates to a method of cutting a fiber-reinforced plastic plate in which high-strength fibers made of any one of fibers, PBO fibers, super-strength polyethylene fibers, and high-strength polyarylate fibers are embedded and reinforced.

  Carbon fiber reinforced plastic plates with carbon fibers, which are high-strength fibers, embedded in cured plastics are reinforced with extremely tough carbon fibers, so they can be used in applications requiring strength such as aerospace and special vehicles. used. As a fiber reinforced plastic sheet cutting apparatus, an apparatus for irradiating a laser beam has been developed. (See Patent Documents 1 and 2)

  The laser beam cutting devices described in these publications consume extremely large energy for cutting fiber-reinforced plastic plates and cannot efficiently cut in a short time. Also, as a fiber reinforced plastic sheet cutting device, a device for cutting with a water jet has been developed. However, this cutting device also consumes a large amount of energy and cannot be cut quickly and efficiently. Further, the laser beam or water jet cutting device has a drawback that both the equipment cost and the running cost are considerably increased.

  By the way, an apparatus for cutting a high-strength fiber material used as an aerospace material has been developed (see Patent Document 3). This cutting apparatus cuts a high-strength fiber material using a special cutting cutter. This cutting cutter has a cutting edge joined to the tip of the shank body. The cutting edge portion gradually decreases in thickness toward the tip. Further, the cutting edge portion is formed of a composite obtained by joining a super-hard portion constituting the cutting edge and a cemented carbide portion connecting the cutting blade and the shank body and integrally sintering the cutting edge portion. The tip of is formed with an ultra-high hardness part. A composite composed of a super-hard part and a super-hard alloy part is a mixture of high-hardness particles such as diamond and particles such as TiN and TiC used as a binding material, and these are press-molded at ultra-high pressure. A pellet-shaped super-hard part formed by sintering at a high temperature and a pellet-type cemented carbide part formed of tungsten carbide or the like were integrally sintered and processed into a predetermined shape. Is.

JP 2010-247206 A JP 2011-56583 A JP-A-4-69187

  Since the apparatus described in Patent Document 3 cuts a high-strength fiber material with a special cutting cutter, it can cut more efficiently than a laser beam or a water jet. However, since this cutting device advances the cutting cutter while reciprocating to cut the high-strength fiber material, the fiber-reinforced plastic plate cannot be cut into a predetermined shape by one reciprocating motion. For this reason, there exists a fault which cannot be cut | disconnected to a specific external shape efficiently in a short time, and a cutting cost becomes high. In addition, since the process of cutting partially is repeated to cut into a predetermined shape, there is a drawback that an infinite number of cracks are likely to be generated along the cutting edge due to excessive force acting locally when cutting. The crack at the cutting edge can be prevented from being exposed to the outside by providing a frame or a covering cover along the outer peripheral edge. However, if there is a crack at the cutting edge, there is a problem that the crack gradually advances inward with time in use and is exposed to the outside from the frame or cover. In addition, cracks that are not apparent can be inherent in the cutting edge of the cutting cutter. In this state, there is a problem that the inherent cracks progress with time and are exposed to the outside. This crack is difficult to find in the manufacturing process and has the disadvantage that the quality of the part is significantly reduced by the subsequent crack. Furthermore, since the above cutting cutter is a composite body in which the ultra-high hardness part of the cutting edge is joined to the shank body by a cemented carbide part and integrally sintered, the cutting cutter has a complicated curve shape. Cannot be machined and cannot be cut into complex external and internal shapes. In addition, this cutting cutter has a disadvantage that it is extremely expensive due to its complicated structure.

The present invention has been developed for the purpose of solving the above-mentioned drawbacks. An important object of the present invention is that a fiber-reinforced plastic plate reinforced with high-strength fibers is punched into a predetermined shape by one reciprocating motion while using an extremely inexpensive punching die, and is extremely efficient and accurate. Another object of the present invention is to provide a method for cutting a fiber reinforced plastic plate that can be cut into a simple outer shape.
Another important object of the present invention is to reduce the manufacturing cost of the punching die while extending its life, and further reducing the cost of punching, thereby making it a fiber reinforced plastic plate that was extremely difficult to cut. It is an object to provide a cutting method capable of processing an accurate shape quickly and efficiently at an extremely low cost.
Another important object of the present invention is that there is no crack at the cutting edge in a state of being processed into an accurate shape, and further, it is possible to effectively prevent a defect that a crack occurs with time, and to be extremely efficient and accurate. An object of the present invention is to provide a method for cutting a fiber-reinforced plastic plate that can be processed into a shape.

Means for Solving the Problems and Effects of the Invention

  The present invention provides a fiber-reinforced plastic plate in which a high-strength fiber 15 made of carbon fiber, Kepler fiber, PBO fiber, super-strength polyethylene fiber, or high-strength polyarylate fiber is embedded and reinforced in a cured plastic. This is a method of cutting, and after the breaking step of breaking the fiber reinforced plastic plate 10 into a linear shape to form a breaking plate 11 having a predetermined shape, the breaking plate 11 is formed into a predetermined shape by a grinding step. In the breaking process, the fiber reinforced plastic plate 10 is placed on the cut surface 2 of the cradle 1, and the fiber reinforced plastic plate 10 is cut and punched on the surface of the fiber reinforced plastic plate 10 arranged in the cut surface 2. 4, the cutting die 3 is pressed, and the fiber reinforced plastic plate 10 is broken by the punching die 3 and punched as the breaking plate 11 having the grinding scissors 16 at the breaking edge 11A. In the grinding process, the grinding plate 16 of the fracture plate 11 punched in the fracture process is ground to adjust the cutting edge 11B of the fracture plate 11 to a predetermined shape.

  The above fiber reinforced plastic plate cutting method is extremely efficient by punching a fiber reinforced plastic plate, which is extremely difficult to cut, into a predetermined outer shape with a single reciprocating motion while using an extremely inexpensive punching die. Can be cut into an accurate outline. In addition, the above cutting method can extend the service life while reducing the manufacturing cost of the punching die, and further reduce the cost of punching processing, so that the fiber-reinforced plastic plate can be efficiently and quickly obtained at an extremely low cost. Can be processed into a shape. Up to now, the above methods are considered to be extremely difficult to cut with a blade, and in reality, fiber reinforcement reinforced with high-strength fibers that have been cut with an inefficient method that is extremely expensive, such as water jet. A plastic plate can be processed into a predetermined shape extremely efficiently while significantly reducing processing costs.

  Furthermore, the special feature of the above cutting method is that it can prevent cracks at the cutting edge while efficiently processing at low cost, and can also reliably prevent cracks that occur over time in the state of use. This cutting method realizes an ideal characteristic as a cutting method for fiber-reinforced plastic plates reinforced with high-strength fibers, which cannot be imagined at all.

  In the above cutting method, the fiber reinforced plastic plate is processed into an accurate shape in the breaking process and the grinding process, but in the breaking process, it is cut into a predetermined shape by cutting with a sharp edge like a knife used for cooking. Not to do. In the breaking step, the fiber-reinforced plastic plate is crushed into a linear shape with a cutting edge, that is, broken into a linear shape and processed into a rupture plate having a predetermined shape. A die that breaks a fiber reinforced plastic plate into a predetermined shape can be processed into an accurate shape by extending the life while reducing the manufacturing cost. This is because the punching die breaks a fiber-reinforced plastic plate reinforced with high-strength fibers so as to be divided by an ax, and processes it into a break plate having a predetermined shape. Further, in this state, the method of processing the fiber reinforced plastic plate into the predetermined shape of the fracture plate can be processed into a predetermined shape by pressing the punching die against the fiber reinforced plastic plate.

  The fracture plate processed into a predetermined shape in the fracture process can have innumerable cracks along the fracture edge. In the breaking process, the fiber-reinforced plastic plate is processed into a breaking plate having a grinding scissor at the breaking edge. There are innumerable cracks in the grinding wheel. In other words, the fiber reinforced plastic plate is processed in the breaking process so as to leave an area where a crack is generated as a grinding white. In the breaking process, the fiber reinforced plastic plate is broken into a linear shape and processed into a broken plate, so that when it is broken, a very large stress acts locally on the broken edge, and strain remains. Invisible cracks are inherent. In the breaking step, the fiber-reinforced plastic plate is broken as a breaking plate that leaves a region including local stress strain and an inherent crack as a grinding white. Therefore, the fracture plate processed in the fracture process has cracks in the grinding edges of the fracture edges, invisible cracks are inherent, and local stress strain remains. In the fracture plate, the grinding white is removed by grinding in the grinding process, and the crack and stress distortion of the grinding white are completely removed to become a product. Therefore, the fracture plate that has been ground by the grinding process in the grinding process becomes a product that has a clean cutting edge, and does not have cracks or stress distortion at the cutting edge.

In the method for cutting a fiber-reinforced plastic plate of the present invention, the width of the grinding scissor 16 can be 1 mm or more and 20 mm or less.
In this cutting method, the width of the grinding scissors is set to an optimum value according to the thickness and material of the fiber reinforced plastic plate, and the cut edge of the product can be processed into a clean state without cracks.

The cutting method of the fiber-reinforced plastic plate of the present invention can grind the grinding plate 16 of the fracture plate 11 using an abrasive sheet in the grinding step.
In this method, the fracture plate can be efficiently ground with an abrasive sheet and processed into a product having no cracks at the cutting edge.

The cutting method of the fiber-reinforced plastic plate of the present invention can grind the grinding plate 16 of the fracture plate 11 using a polishing grindstone in the grinding step.
This method can efficiently grind the fracture plate with a grinding wheel.

In the cutting method of the fiber reinforced plastic plate of the present invention, the fiber reinforced plastic plate 10 is processed as a rupture plate 11 having a grinding slab 16 on the outer peripheral edge in the breaking step, and the outer periphery of the rupture plate 11 in the grinding step 16 can be ground into a product.
This cutting method can efficiently produce a product having a specific outer shape.

In the cutting method of the fiber reinforced plastic plate of the present invention, the fiber reinforced plastic plate 10 is processed as the rupture plate 11 having the grinding scissors 16 on the inner peripheral edge in the breaking step, and the inner circumference of the fracture plate 11 is ground in the grinding step. The white 16 can be ground into a product.
This cutting method can efficiently produce a product whose inner shape is a specific shape.

In the method for cutting a fiber-reinforced plastic plate of the present invention, in the breaking step, a plate-like carbon steel having a carbon content of 0.45% or more and 1.4% or less is bent or curved into a predetermined shape. The blade edge 4 is hardened to a state where the HRC hardness of the blade edge 4 is 62 or more, and the blade edge inclination angle (α) of the cross-sectional shape perpendicular to the longitudinal direction of the blade edge 4 is larger than 25 degrees to 60 degrees. Using a punching die 3 that is smaller than the punching die 3, the punching die 3 is reciprocated and punched by sandwiching the fiber reinforced plastic plate 10 disposed on the cut surface 2 of the receiving stand 1 between the receiving stand 1 and the punching die 3. Thus, the fracture plate 11 can be processed.
However, in this specification, the “blade edge inclination angle (α)” means an angle formed by both opposing surfaces of the blade edge portion.

  The above-described method for cutting a fiber reinforced plastic plate is characterized in that the fiber reinforced plastic plate can be processed into a fracture plate with a very inexpensive punching die. It uses a plate-shaped carbon steel with a carbon content of 0.45% to 1.4% as the cutting die used in the breaking process, and has a shape along the breaking edge of the breaking plate of various shapes. Bending or curving and processing so that the cutting edge angle of the cross section perpendicular to the longitudinal direction of the cutting edge is larger than 25 degrees and smaller than 60 degrees, and the HRC hardness of the cutting edge is set to 62 or more. This is because it is manufactured by putting it into a shape along the break edges of various break plates using a very inexpensive material.

  The above cutting method uses carbon fiber reinforced plastic plate, Kepler fiber reinforced plastic plate, PBO fiber reinforced plastic plate, super strong polyethylene fiber reinforced plastic plate, high strength with a thickness of 2 mm by using a unique punching die. Even when 200 to 300 polyarylate fiber reinforced plastic plates are punched, the blade edge is not damaged, and the punching is possible.

The cutting method of the fiber-reinforced plastic plate of the present invention can use the die 3 having a shape that gradually increases the blade edge inclination angle (α) toward the blade edge 4 in the breaking step.
In this cutting method, the cutting edge inclination angle (α) of the cutting edge of the punching die is increased and the cutting is good, and the cutting edge inclination angle (α) is gradually decreased as the cutting edge is inserted into the fiber reinforced plastic plate. Inserted into the crevice. For this reason, the characteristic which can fracture a fiber reinforced plastic board more effectively is realized.

  The cutting method of the fiber-reinforced plastic plate of the present invention can use the punching die 3 having a blade edge inclination angle (α) larger than 30 degrees in the breaking step.

The cutting method of the fiber-reinforced plastic plate of the present invention can use the punching die 3 in which the HRC hardness of the cutting edge 4 is 64 or more in the breaking process.
In this cutting method, since the HRC hardness of the cutting edge of the punching die is 64 or more, the cutting edge has a higher hardness and can have a long life.

Furthermore, the cutting method of the fiber reinforced plastic plate of this invention can use the single-blade die 3 in a fracture | rupture process.
In this cutting method, since one blade surface is a vertical surface and the other is an inclined surface, the cutting edge on the vertical surface side can be finely punched and broken.

In the cutting method of the fiber reinforced plastic plate of the present invention, in the breaking process, the cutting edge 4 of the punching die 3 and the cut surface 2 of the cradle 1 are formed into a three-dimensional curved surface that is three-dimensionally shaped into a three-dimensional curved surface. The fiber-reinforced plastic plate 10 can be processed.
In this cutting method, the cutting edge of the punching die and the cut surface of the cradle have a three-dimensional curved surface. Therefore, the fiber-reinforced plastic plate molded into a three-dimensional curved surface is cleanly and efficiently used as a fracture plate with the cutting edge as a three-dimensional curved surface. Can be stamped.

In the method for cutting a fiber reinforced plastic plate of the present invention, the plastic of the fiber reinforced plastic plate 10 can be made of an epoxy resin.
According to the above cutting method, a fiber reinforced plastic plate made of a hardened epoxy resin made of plastic embedding high-strength fibers can be efficiently punched and processed into a rupture plate having a predetermined shape.

  In the fiber reinforced plastic plate cutting method of the present invention, the thickness of the punch 3 can be made into plate-like carbon steel that is thicker than 1 mm and thinner than 10 mm.

It is a schematic perspective view of the punching apparatus used for the cutting method of the fiber reinforced plastic board concerning one Example of this invention. FIG. 2 is a partially enlarged vertical sectional view showing a punching die of the punching device shown in FIG. 1. It is a schematic perspective view of the punching apparatus used for the cutting method of the fiber reinforced plastic board concerning the other Example of this invention. FIG. 4 is a partially enlarged vertical sectional view showing a punching die of the punching device shown in FIG. 3. It is a vertical sectional view of the punching device used for the cutting method of the fiber reinforced plastic board concerning other examples of the present invention. It is an expanded sectional view which shows the state which a cutting die fractures | ruptures a fiber reinforced plastic board. It is a vertical sectional view showing another example of the punching die. It is an expanded sectional view which shows an example of a cutting die. It is an expanded sectional view which shows another example of a cutting die. It is a top view which shows an example of the fracture | rupture plate processed with the punching apparatus shown in FIG. 1 thru | or FIG. It is a cross-sectional view showing an example of a conventional punching die.

  Embodiments of the present invention will be described below with reference to the drawings. However, the example shown below illustrates the cutting method of the fiber reinforced plastic board for embodying the technical idea of the present invention, and the present invention does not specify the cutting method as the following method. Further, in this specification, in order to facilitate understanding of the scope of claims, numbers corresponding to the members shown in the examples are indicated in the “claims” and “means for solving problems” sections. It is added to the members. However, the members shown in the claims are not limited to the members in the embodiments.

  The method for cutting a fiber-reinforced plastic plate according to the present invention is obtained by embedding a high-strength fiber made of any of carbon fiber, Kepler fiber, PBO fiber, super-strength polyethylene fiber, and high-strength polyarylate fiber in a cured plastic. This is a method of cutting a fiber reinforced plastic plate. The cutting method of the present invention is a method of punching any one of a carbon fiber reinforced plastic plate, a Kepler fiber reinforced plastic plate, a PBO fiber reinforced plastic plate, a super strong polyethylene fiber reinforced plastic plate, and a high strength polyarylate fiber reinforced plastic plate with a die. Processed and broken into a broken plate, and the broken edge of this broken plate was ground to obtain a product with an accurate shape. In the cutting method of the present invention, any one of carbon fiber, Kepler fiber, PBO fiber, super-strength polyethylene fiber, and high-strength polyarylate fiber is embedded in a hardened plastic such as epoxy resin or phenol resin. The fiber-reinforced plastic plate that can be cut. The cutting method of the present invention is not an apparatus that cuts a prepreg of a fiber reinforced plastic plate that is made into a fiber reinforced plastic plate by curing the plastic when the plastic is in an uncured state. This is a method of cutting a fiber-reinforced plastic plate that has been cured.

  The fiber-reinforced plastic plate in which high-strength fibers are embedded is processed into a predetermined shape of a fracture plate by a punching device. The breaking plate is processed into a product having an accurate outer shape by grinding the breaking edge. 1 to 5 show a punching device that breaks a fiber-reinforced plastic plate of high-strength fibers into a predetermined shape of a break plate.

  The punching apparatus shown in these figures moves to a cradle 1 having a cut surface 2 on the upper surface on which a fiber reinforced plastic plate 10 is placed and cut with a punching die 3, and moves toward the cut surface 2 of the cradle 1. A punching die 3 having a cutting edge 4 for punching a fiber-reinforced plastic plate 10 arranged on the surface 2 in a non-linear shape with a predetermined length along a cutting edge 11A of the fracture plate 11, and the punching die 3 reciprocatingly. And a blade driving mechanism 5 to be moved.

  The cradle 1 is a metal plate, and the apparatus shown in FIGS. The cradle 1 of FIG. 5 has a cut surface 2 as a three-dimensional solid curved surface. The cradle may be a resin or a rubber plate. The cut surface 2 has a shape along the break edge 11A of the break plate 11 obtained by breaking the fiber-reinforced plastic plate 10, that is, along the break edge 11A. Accordingly, the cradle 1 for punching the fracture plate 11 having a planar shape with the fracture edge 11A to be fractured punches a fracture plate having the cut surface 2 as a planar surface and the fracture edge to be fractured as a three-dimensional solid curved surface. The cradle 1 to be processed has a three-dimensional curved surface along the fracture edge 11 </ b> A of the fracture plate 11.

  The cradle 1 shown in FIGS. 1 to 5 has an elastic sheet 1 </ b> A laminated on a cut surface 2. The elastic sheet 1A is a sheet-like rubber-like elastic body having a thickness of 1 mm to 10 mm. The cradle 1 in which the elastic sheet 1A is laminated on the upper surface is in a state in which the fiber reinforced plastic plate 10 is punched with the die 3 and the cutting edge 4 of the die 3 is brought into close contact with the elastic sheet 1A. By inserting the blade edge 4 into the elastic sheet 1A, the break edge 11A of the break plate 11 punched out from the fiber reinforced plastic plate 10 can be reliably broken. The cradle 1 in which the elastic sheet 1A is laminated on the upper surface can cleanly break the fracture plate having the fracture edge 11A as a solid curved surface at the fracture edge 11A. However, the rupture plate 11 having the rupture edge 11A as a flat surface can also be ruptured neatly by laminating the elastic sheet 1A on the cut surface 2 as a flat surface. However, the cradle does not necessarily need to have an elastic sheet on the upper surface, and the fiber reinforced plastic plate can be punched and broken by bringing the punching die closer to or in contact with the cut surface of the cradle.

  The punching die 3 is made of a plate-like carbon steel having a carbon content of 0.45% to 1.4%. The punching die is preferably made of sheet carbon steel having a thickness of 2 mm to 5 mm. However, the punching die can be a plate-like carbon steel having a thickness greater than 1 mm and less than 10 mm. If the punching die is too thin, it is likely to be damaged by the impact of the punching process, and if it is too thick, the ruptured material that is broken and inserted inside the punching die cannot be removed smoothly.

  The punching die is bent or bent in the previous step of quenching the plate-like carbon steel and processed into a shape along the breaking edge 11A of the breaking plate 11 to be broken. The carbon steel optimal for the punching die 3 has a carbon content of 0.5% to 0.7%. However, the carbon content can be used within the above range. The carbon steel of the die 3 can be hardened by increasing the carbon content. However, since it becomes brittle as the carbon content increases, it is set to an optimum value within the aforementioned range in consideration of hardness and brittleness.

  In the punching die 3 in which the cutting edge 4 is processed into a shape along the breaking edge 11A of the breaking plate 11, the cutting edge 11 is used as a closed loop, and the fiber reinforced plastic plate 10 is punched by the closed loop cutting edge 4 to separate the breaking plate 11. . In the plate-like carbon steel obtained by processing the plate-like carbon steel into a closed loop, the cutting edge 4 is polished to provide the cutting edge 4. The punching die 3 is polished so as to incline one side of the plate-like carbon steel to provide the cutting edge 4, and then hardened by hardening. 2 and 4 is obtained by polishing plate carbon steel so that the tip angle in the cross-sectional shape perpendicular to the longitudinal direction of the cutting edge 4, that is, the cutting edge inclination angle (α) is about 40 degrees. Yes. The plate-like carbon steel can be polished with a file or a grindstone to provide the cutting edge 4.

  Even if the cutting edge inclination angle (α) is large or small, the breaking ability of the fiber-reinforced plastic plate is lowered. Therefore, the cutting edge inclination angle (α) of the punching die 3 is larger than 25 degrees, preferably larger than 30 degrees. Further, the cutting edge inclination angle (α) of the punching die is made smaller than 60 degrees.

  FIG. 6 is a cross-sectional view showing a state in which the fiber reinforced plastic plate is broken by a punching die and processed into a broken plate in the breaking step. As shown in this figure, the punching die 3 presses the blade edge 4 against the surface of the fiber reinforced plastic plate 10, and as shown in FIG. To make a crack 14. Further, when the cutting edge 4 of the punching die 3 breaks the fiber reinforced plastic plate 10 deeply, as shown in FIG. 6 (2), the wedge portion 3A located above the cutting edge 4 in the drawing is inserted into the crack 14, The crack 14 is expanded. In a state where the wedge portion 3A expands the crack 14, the high-strength fiber 15 embedded in the cured plastic is easily pulled by the plastic on both sides of the crack 14 and easily cut. In this state, the cutting edge 4 of the punching die 3 is further inserted deeply into the crack 14 to cut the high-strength fibers 15 that are easily cut. The cutting edge 4 of the punching die 3 is further inserted deeply into the crack 14 to completely break the fiber reinforced plastic plate 10.

  The cutting die 3 in FIG. 6 has a shape in which the cutting edge inclination angle (α) gradually increases toward the cutting edge 4. The punching die 3 can increase the cutting edge inclination angle (α) of the cutting edge 4 to prevent damage to the cutting edge, and reduce the cutting edge inclination angle (α) of the wedge portion 3A to reduce the surface of the fiber reinforced plastic plate 10. The fiber-reinforced plastic plate 10 can be more efficiently broken by smoothly inserting the wedge portion 3A into the crack 14 that can be formed.

  The punching die 3 used in the punching device has an extremely large blade edge inclination angle (α) compared to the conventional punching die 3. The cross-sectional view of FIG. 11 shows a cross-sectional view of a conventional punching die 93. As shown in this figure, the conventional cutting die 93 has a shape in which the cutting edge inclination angle (α) is considerably small, and the to-be-broken sheet 90 and the like are reliably cut by the sharp cutting edge 94.

  In the punching die, the hardened plate-like carbon steel is hardened to a unique hardness, and the cutting edge inclination angle (α) is remarkably increased as compared with the conventional punching die. This punching die does not break the breaking plate with only a sharp cutting edge, unlike the conventional punching die. The punching die 3 having a specific hardness and a specific cutting edge inclination angle (α) efficiently breaks the fiber reinforced plastic plate 10 that is too hard to be easily broken by the cutting tool, so that the cutting edge 4 is not damaged. This is because, as shown in FIG. 6, the wedge portion 3 </ b> A is inserted into the crack 14 of the fiber reinforced plastic plate 10, and the high-strength fibers 15 are broken in a state where they are easily cut.

  2 and 4 has a cutting edge 4 as a single blade. In the single-blade punching die 3, since one side of the cutting edge 4 is a vertical surface 4A, the vertical surface 4A can be used as the breaking edge 11A of the breaking plate 11, and the breaking edge 11A of the breaking plate 11 can be broken with few cracks. The fiber reinforced plastic plate 10 is punched by the punching die 3 and separated into a fracture plate 11 to be a product and a discarding portion 13 to be discarded. The punching die 3 in FIG. 2 punches the fiber reinforced plastic plate 10 as a fracture plate 11 having a predetermined outer shape. This punching die 3 is a single-edged blade having an inclined surface 4B on the outer peripheral surface, and a portion punched as a breaking plate 11 having a predetermined outer shape is used as a product, and the outer side of the breaking plate 11 is used as a discarding portion 13 and the breaking edge 11A of the breaking plate 11 is used. Can be broken with fewer cracks than the waste part 13. This is because the break edge 11A is broken at the vertical surface 4A of the punch 3. The punching die 3 in FIG. 4 is a fracture plate 11 that punches a fiber-reinforced plastic plate 10 and processes the outside of the punching die 3 into a product. That is, the through holes 12 and the like are processed in the product. This punching die 3 is a single-edged blade having an inclined surface 4B on the inside, and a portion punched inside the punching die 3 is a discarding portion 13 and a portion separated outside the punching die 3 is a breaking plate 11, and the inside of the breaking plate 11 The peripheral break edge 11A can be broken cleanly.

  Further, as shown in FIG. 7, the cutting die 3 can have a cutting edge 4 as a double-edged blade having inclined surfaces 4B on both sides.

  2 and FIG. 4, the fiber reinforced plastic plate 10 is cut into a flat shape. As shown in FIG. 5, the die 3 has a structure in which the fiber reinforced plastic plate 10 molded into a three-dimensional curved surface has a three-dimensional structure with the cutting edge 4 along the three-dimensional curved surface. It can also be punched into a curved surface and broken. In this punching die 3, the cutting edge 4 is a three-dimensional curved surface, and the cut surface 2 of the cradle 1 is also a three-dimensional curved surface along the cutting edge 4 of the punching die 3.

  Furthermore, as shown in the enlarged cross-sectional view of FIG. 8, the cutting die 3 gradually increases the blade edge inclination angle (α) toward the blade edge 4. The reason why the cutting edge inclination angle (α) is increased toward the cutting edge 4 is to prevent damage to the cutting edge 4 while efficiently breaking the hard and tough fiber-reinforced plastic plate 10 with the cutting edge 4. In this punching die 3, the cutting edge 4 having a large cutting edge inclination angle (α) is first brought into contact with the surface of the fiber reinforced plastic plate 10 to start breaking, and after the breakage is started, the cutting edge inclination angle (α) is increased. The rupture plate 11 and the discarding portion 13 are separated from each other at a gradually decreasing portion so as to break. The cutting die 3 shown in the enlarged cross-sectional view of FIG. 8 is polished so that the inclined surface 4B of the single blade is curved, and the cutting edge inclination angle (α) is gradually increased toward the cutting edge 4. As shown in the enlarged cross-sectional view of FIG. 9, the punching die 3 can be polished so that the cutting edge inclination angle (α) gradually increases toward the cutting edge 4.

  The plate-like carbon steel is hardened so that the HRC hardness of the cutting edge 4 is 62 or more, preferably about 65 in a state where the tip edge is polished and the cutting edge 4 is provided. The hardness of the cutting edge 4 can be increased to increase the life, but if it is too hard, it becomes brittle and easily damaged during punching. Accordingly, the die 3 is quenched so that the HRC hardness of the cutting edge 4 is higher than 62, preferably higher than 64, and lower than 72, preferably lower than 66. The hardness of the cutting edge 4 after quenching is controlled by the carbon content and the quenching temperature. The hardness of the cutting edge 4 can be increased by increasing the quenching temperature, and the hardness can be decreased by decreasing the temperature. For example, the carbon steel has a carbon content of 0.6%, a quenching temperature of 780 ° C. to 950 ° C., and an HRC hardness in the range of 62 to 72 described above. The punching die 3 having an HRC hardness of 65 after quenching can have this hardness with a carbon content of 0.6% and a quenching temperature of 850 ° C.

  As shown in FIGS. 1 to 5, the blade driving mechanism 5 reciprocates the punching die 3 up and down to punch the fiber reinforced plastic plate 10 placed on the cut surface 2 of the cradle 1 with the punching die 3. And break. The blade drive mechanism 5 includes an upper and lower base 6 that fixes the punch 3 and a cylinder 7 that reciprocates the upper and lower base 6 up and down. The punching die 3 is fixed to the lower surface of the upper and lower table 6, and the upper and lower table 6 is reciprocated up and down by a cylinder 7 to punch the fiber reinforced plastic plate 10 placed on the receiving table 1. That is, the die 3 is reciprocated by the blade driving mechanism 5, the fiber reinforced plastic plate 10 disposed on the cut surface 2 of the cradle 1 is sandwiched between the cradle 1 and the die 3, and the fracture plate 11 is broken. Punches along the edge 11A and breaks.

  An example of the breaking plate 11 obtained by the above breaking process is shown in FIG. The fracture plate 11 shown in this figure is obtained by breaking the planar fiber-reinforced plastic plate 10 with the punching die 3 along the outer periphery using the punching device shown in FIGS. 1 and 2. Using the punching device shown in FIG. 4, the punching die 3 is broken along the inner peripheral edge of the through-hole 12 and processed into a predetermined shape. Thus, the fracture | rupture plate 11 can be processed into a complicated shape through the fracture | rupture process of multiple times. However, although not shown, the punching device may have a structure in which a plurality of punching dies are combined. This punching device can process the fracture plate into a predetermined shape in a single fracture process.

  As shown in FIG. 10, the fracture plate 11 obtained in the fracture process is processed into a shape that leaves a grinding scissor 16 (indicated by cross-hatching in the figure) on the fracture edge 11A. In the grinding process, the breaking plate 11 is ground into a grinding scissor 16, and this portion is removed to process the product into an accurate shape. The breaking plate 11 of FIG. 10 is provided with a grinding scissor 16 with both the outer peripheral edge and the inner peripheral edge as the breaking edges 11A. The grinding plate 16 of the breaking plate 11 has a width of, for example, 1 mm or more and 20 mm or less, preferably 1.5 mm or more and 10 mm or less, more preferably 2 mm or more and 8 mm or less, optimally about 2 mm to 3 mm. The width of the grinding scissors 16 can be widened to more reliably remove the cracks in the fracture edge 11A and the stress strain remaining inside. However, if the grinding scissors 16 are widened, the grinding process takes time, the grinding cost increases, and the disposal area of the fiber reinforced plastic plate 10 increases, resulting in an increase in product cost. Therefore, the grinding roller 16 is set to an optimum width within the above-mentioned range in consideration of grinding cost and product cost. Further, the grinding scissor 16 can be set to an optimum value in consideration of the thickness of the fiber reinforced plastic plate 10 to reduce grinding cost and product cost. This is because the thin fiber reinforced plastic plate has a narrower cracking region than the thicker one, so that the grinding slab 16 of the thin fracture plate 11 can be made narrower than the thicker one. For example, the breaking plate 11 having a thickness of 0.1 mm to 1 mm has a width of the grinding scissor 16 of about 2 mm, and the breaking plate 11 having a thickness of 2 mm has a width of the grinding scissor 16 of about 3 mm. 11A cracks and stress strains can be removed.

  In the grinding process, the grinding plate 16 of the fracture plate 11 is removed by grinding with abrasive paper or by grinding with a grindstone. A grinding paper 16 can be removed by using a 100-2000 mesh abrasive paper or a grinding wheel. Also, in the grinding step, the grinding scissors 16 can be ground in a more preferable state by first grinding with a coarse abrasive paper or grinding stone and then grinding with a small grain abrasive paper or grinding stone. Further, by grinding the grinding scissors 16 with an NC processing machine, it can be efficiently processed into a product with an extremely accurate shape.

  The fracture plate 11 is completed as a product by grinding the grinding scissors 16. After the grinding plate 16 is ground and removed, the fracture plate 11 can further protect the cutting edge 11B by applying plastic along the cutting edge 11B which is a grinding edge. The plastic applied to the cutting edge 11B is an uncured liquid or paste plastic adhesive such as a cyanoacrylate adhesive, an epoxy resin adhesive, or a urethane resin adhesive. Agents can be used. Moreover, it can also apply | coat in the state which heat-melts a thermoplastic resin. The plastic applied to the cutting edge 11B is bonded to the cutting edge 11B where the grinding scissors 16 are ground, and more effectively prevents cracking of the cutting edge 11B due to impact.

DESCRIPTION OF SYMBOLS 1 ... Receptacle 1A ... Elastic sheet 2 ... Cut surface 3 ... Cutting die 3A ... Wedge part 4 ... Cutting edge 4A ... Vertical surface
4B ... Inclined surface 5 ... Blade drive mechanism 6 ... Upper / lower platform 7 ... Cylinder 10 ... Fiber reinforced plastic plate 11 ... Breaking plate 11A ... Breaking edge
DESCRIPTION OF SYMBOLS 11B ... Cutting edge 12 ... Through-hole 13 ... Waste part 14 ... Crack 15 ... High-strength fiber 16 ... Grinding sheet 90 ... Breaking sheet 93 ... Cutting die 94 ... Cutting edge

Claims (14)

A method for cutting a fiber-reinforced plastic plate, in which a high-strength fiber (15) made of carbon fiber, Kepler fiber, PBO fiber, super-strength polyethylene fiber, or high-strength polyarylate fiber is embedded in a cured plastic. ,
The fiber reinforced plastic plate (10) is placed on the cut surface (2) of the cradle (1), and on the surface of the fiber reinforced plastic plate (10) disposed on the cut surface (2), a fiber reinforced plastic plate ( 10) The cutting edge (4) of the cutting edge (4) to be broken and punched into a line is pressed, and the fiber-reinforced plastic plate (10) is broken with this cutting mold (3) to break the edge (11A ) Punching process as a breaking plate (11) provided with grinding scissors (16),
A fiber-reinforced plastic comprising a grinding step of grinding the cutting plate (11) of the breaking plate (11) punched in the breaking step and processing the cut edge (11B) of the breaking plate (11) into a predetermined shape How to cut a board.   The fiber-reinforced plastic plate cutting method according to claim 1, wherein the width of the grinding scissor (16) is 1 mm or more and 20 mm or less.   The method for cutting a fiber-reinforced plastic plate according to claim 1 or 2, wherein in the grinding step, the grinding scoring (16) is ground using an abrasive sheet.   The method for cutting a fiber-reinforced plastic plate according to claim 1 or 2, wherein, in the grinding step, the grinding scoring (16) is ground using a polishing grindstone. In the breaking step, the fiber-reinforced plastic plate (10) is processed as a breaking plate (11) having a grinding scissor (16) on the outer periphery,
The method for cutting a fiber-reinforced plastic plate according to any one of claims 1 to 4, wherein the grinding scoring (16) on the outer periphery of the fracture plate (11) is ground in the grinding step. In the breaking step, the fiber-reinforced plastic plate (10) is cut into a predetermined inner shape leaving a grinding scissor (16) on the inner periphery,
The method for cutting a fiber-reinforced plastic plate according to any one of claims 1 to 5, wherein the grinding plate (16) provided on the inner periphery of the fracture plate (11) fractured in the grinding step is ground. In the breaking step, a cutting edge (3) is formed by bending or bending a plate-like carbon steel having a carbon content of 0.45% to 1.4% into a predetermined shape to obtain a cutting edge (4) The HRC hardness of the steel sheet is hardened to 62 or higher, and the cutting edge inclination angle (α) of the cross-sectional shape perpendicular to the longitudinal direction of the cutting edge (4) is larger than 25 degrees and smaller than 60 degrees. Use the punching die (3)
Reciprocating the punching die (3), and sandwiching the fiber reinforced plastic plate (10) disposed on the cut surface (2) of the cradle (1) between the cradle (1) and the punching die (3) The method for cutting a fiber reinforced plastic plate according to claim 1, wherein the fiber reinforced plastic plate is cut by punching.   The method for cutting a fiber-reinforced plastic plate according to claim 7, wherein a punching die (3) is used in which the cutting edge inclination angle (α) is gradually increased toward the cutting edge (4) in the breaking step.   The method for cutting a fiber reinforced plastic plate according to claim 7, wherein a punching die (3) having a cutting edge inclination angle (α) larger than 30 degrees is used in the breaking step.   The method for cutting a fiber-reinforced plastic plate according to any one of claims 7 to 9, wherein a punching die (3) in which the cutting edge (4) has an HRC hardness of 64 or more is used in the breaking step.   The method for cutting a fiber-reinforced plastic plate according to any one of claims 7 to 10, wherein a one-blade punching die (3) is used in the breaking step.   In the breaking step, the cutting edge (4) of the punching die (3) and the cut surface (2) of the cradle (1) are shaped into a three-dimensional curved surface, and the fiber reinforcement is molded into a three-dimensional curved surface. The method for cutting a fiber-reinforced plastic plate according to any one of claims 7 to 11, wherein the plastic plate (10) is processed.   13. The method for cutting a fiber reinforced plastic plate according to claim 1, wherein the plastic of the fiber reinforced plastic plate (10) is an epoxy resin.   The method for cutting a fiber-reinforced plastic plate according to any one of claims 1 to 13, wherein a punching die (3) having a thickness larger than 1 mm and thinner than 10 mm is used in the breaking step.

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