Abstract
A metal fiber for fiber reinforced concrete includes a linear main body that extends in an X-Y plane, having width in a Y direction, a length in an X direction, and a thickness in a Z direction within a three dimensional space defined by X, Y, and Z axes which are perpendicular to each other. Ends of the linear main body are bent portions which are bent at an obtuse angle in the Z direction. An elongate metal plate is intermittently conveyed in the Y direction on a die of a pressing machine at a pitch corresponding to the width of the metal fiber in the Y direction. The leading end of the metal plate is sheared to cut out and produce the metal fiber.
Claims
1. A metal fiber for fiber reinforced concrete comprising: a width in a Y direction, a length in an X direction, and a thickness in a Z direction within a three dimensional space defined by X, Y, and Z axes which are perpendicular to each other; the metal fiber being constituted by a linear main body in the form of a wave that extends within the X-Y plane, and a bent portion at at least one end of the main body which is bent at an obtuse angle in the Z direction.
2. A method for producing the metal fiber according to claim 1, comprising intermittently advancing a metal plate in the form of a band having a thickness in the Z direction of the metal fiber, a width in the X direction greater than or equal to the length of the metal fiber, and extends in the Y direction on a die of a pressing machine at a pitch corresponding to the width of the metal fiber in the Y direction, and cutting the ends in the X direction of the metal fiber with a cutting blade of a punch of the pressing machine, while a pressing portion that protrudes in the Z direction from the lower surface of the punch simultaneously presses the metal fiber in the Z direction.
3. A pressing machine for cutting the metal fiber by the method according to claim 2, comprising: a die having a lower blade in the form of a wave which is the contour of the linear main body that extends in the X-Y plane of the metal fiber; and a punch that moves vertically in the Z direction, having an upper blade that corresponds to the lower blade of the die, the punch having a pressing portion that protrudes downward from the lower surface thereof, for pressing the metal fiber downward in the Z direction simultaneously with the punch cutting the ends in the X direction of the metal fiber.
4. A pressing mold utilized by the pressing machine for cutting the metal fiber according to claim 3, comprising: a die having a lower blade in the form of a wave which is the contour of the linear main body that extends in the X-Y plane of the metal fiber; and a punch that moves vertically in the Z direction, having an upper blade that corresponds to the lower blade of the die, the punch having a pressing portion that protrudes downward from the lower surface thereof, for pressing the metal fiber downward in the Z direction simultaneously with the punch cutting the ends in the X direction of the metal fiber.
5. A method for producing a metal fiber for reinforcing concrete having a width in a Y direction, a length in an X direction, and a thickness in a Z direction within a three dimensional space defined by an X, a Y, and a Z axis which are perpendicular to each other and is constituted by a linear main body in the form of a wave that extends in an X-Y plane with a pressing machine, comprising: intermittently advancing a metal plate in the form of a band that extends in the Y direction having the above thickness in the Z direction and a width greater than or equal to the above length in the X direction at a pitch corresponding to the width in the Y direction in the Y direction onto a die equipped with a lower blade in the shape of a wave having the contour of the linear main body in the form of a wave; and cutting the leading edge of the metal plate in a conveyance direction with a punch that moves vertically in the Z direction and has an upper blade in the shape of a wave that corresponds to the lower blade of the die of the pressing machine.
6. A pressing machine to be utilized for the method defined in claim 5, comprising: a die having lower blade in the shape of a wave which is the contour of a linear main body in the form of a wave that extends in an X-Y plane of the metal fiber; and a punch that moves vertically in the Z direction and has an upper blade in the shape of a wave that corresponds to the lower blade of the die.
7. A pressing mold to be utilized for the method defined in claim 5, comprising: a die having lower blade in the shape of a wave which is the contour of a linear main body in the form of a wave extends in an X-Y plane of the metal fiber; and a punch that moves vertically in the Z direction and has an upper blade in the shape of a wave that corresponds to the lower blade of the die.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a collection of diagrams that illustrate at least one embodiment of a metal fiber according to the invention, wherein A is a perspective view of an example, B is an end view thereof as viewed from a length direction thereof (X direction), C is a front view as viewed from a thickness direction thereof (Z direction), and D is a plan view as viewed from a bending direction of a form of a wave thereof (Y direction).
[0020] FIG. 2 is a plan view that illustrates the basic configuration of an apparatus for producing the metal fiber of at least one embodiment, and the directions of the axes X, Y, Z are illustrated in the drawing.
[0021] FIG. 3 is a collection of plan views for explaining an operating state in which a metal plate is conveyed to an apparatus for producing the metal fiber of at least one embodiment and a punch is driven for the first time to cut off a leading end of the metal plate, wherein A illustrates the state of the machine and B is a diagram of a first piece which is sheared from the leading end of the metal plate, as viewed from the Z direction.
[0022] FIG. 4 is a collection of plan views for explaining an operating state in which a metal plate is conveyed to an apparatus for producing the metal fiber of at least one embodiment and a punch is driven to cut off a leading end of the metal plate, wherein A illustrates the state of the machine, B is a diagram of a piece which is sheared from the leading end of the metal plate, as viewed from the Z direction, and C is a diagram of a metal fiber obtained from the metal plate by being sheared by the punch, as viewed from the Y direction.
[0023] FIG. 5 is a cross sectional diagram taken along line V-V in FIG. 2 for explaining a state when a punch of an apparatus for producing the metal fiber according to at least one embodiment of the invention cuts a leading end of a conveyed metal plate by a punch shearing the metal plate.
[0024] FIG. 6 is a collection of diagrams that illustrate a die having a lower blade of a pressing mold of the machine for producing the metal fiber according to at least one embodiment of the invention, wherein A is a plan view, B is a front view taken from the right direction in A, C is an end view taken from the lower portion of A, and D is a perspective view.
[0025] FIG. 7 is a collection of diagrams that illustrate a punch having an upper blade of the pressing mold of the machine for producing the metal fiber according to at least one embodiment of the invention, wherein A is a bottom view taken from the lower Z direction and B is a front view taken from the Y direction.
[0026] FIG. 8 is a collection of perspective views of the punch of FIG. 7, wherein A is a perspective view taken from the upper front, and B is a perspective view taken from the upper back.
[0027] FIG. 9 is a perspective view that illustrates a heel back of the machine for producing the metal fiber according to at least one embodiment of the invention that supports and guides the punch from behind that slides during vertical motion of the punch.
[0028] FIG. 10 is an end view that illustrates the heel back of FIG. 9 from the side.
[0029] FIG. 11 is a collection of diagrams that illustrate a metal fiber according to at least one embodiment of the invention, wherein A is a perspective view of an example, B is an end view thereof as viewed from a length direction thereof (X direction), C is a front view as viewed from a thickness direction thereof (Z direction), and D is a plan view as viewed from a bending direction of a form of a wave thereof (Y direction).
[0030] FIG. 12 is a collection of diagrams that illustrate a punch having an upper blade of a pressing mold of the machine for producing the metal fiber according to at least one embodiment of the invention, wherein A is a bottom view taken from beneath the punch in the Z direction, and B is a front view as viewed from the Y direction.
DETAILED DESCRIPTION OF THE INVENTION
[0031] One or more embodiments of the invention will be described below, with reference to the attached drawings. First, the configuration of one or more embodiments of a metal fiber of the invention will be described with reference to FIG. 1. A through D of FIG. 1 illustrate one or more embodiments of the metal fiber of the invention. As is clear from these drawings, the metal fiber 10 of at least one embodiment of the invention is formed as a linear main body that extends from a first end 11 to a second end 15, and has an intermediate portion in which a peak portion 12, a valley portion 13, and a peak portion 14 connected in this order in the shape of a wave. The intermediate portion having the peak portion 12, the valley portion 13, and the peak portion 14 extend within an X-Y plane. The two ends 11 and 15 are bent at obtuse angles from the X-Y plane in a Z direction, resulting in the metal fiber 10 having a three dimensional shape as a whole. As a modification, a portion of the valley portion 13 at the center of A of FIG. 1 may be deformed in the Z direction as well as the two ends 11 and 15. Portions which are displaced in the Z direction may be present other than at the two ends in this manner. Alternatively, a portion which is displaced in the Z direction may be present only at one end instead of two ends. Note that the number of peak portions and valley portions is not limited to that of the example above, and may be increased or decreased according to intended uses. In addition, the size and the shapes of the bends of the metal fiber may also be freely designed according to intended uses. For an example of a metal fiber for reinforcing concrete, that having a length of 30 mm, a width of 0.7 mm, a thickness of 0.6 mm, a difference (height) between the peak portions and the valley portions of 2 mm, and a bend of 0.78 mm for the bent ends may be considered. These dimensions are freely variable as a matter of course.
[0032] Next, FIG. 2 illustrates a die 21, a punch 22, and a heel back 23 that supports and guides the punch 22 from behind that slides during vertical motion of the punch 22, which are set in a pressing machine that cuts and produces the metal fiber of the invention by shearing the metal fiber from a metal plate (steel plate). The die 21 has blade tips of a lower blade 21a of a shape that corresponds to the contour in the X-Y plane of the metal fiber 10 to be cut out. The punch 22 has blade tips of an upper blade 22a of a shape that corresponds to the lower blade 21a. The gap between the blade tips of the lower blade 21a and the blade tips of the upper blade 22a illustrated in FIGS. 2, 3, and 4 correspond to the width of the metal fiber 10 to be cut out from the metal plate 25 by shearing. Note that the gap is emphasized and exaggerated in the drawings.
[0033] Next, the operation of an apparatus for producing the metal fiber of at least one embodiment of the invention will be described with reference to FIGS. 3, 4, 5, and 6. First, the metal plate 25 having a width W equal to the length of a metal fiber to be cut out in an X direction and that extends in a Y direction is conveyed from the left side of the drawings (FIG. 3). Note that in at least one embodiment, the width W of the metal plate 25 is equal to the length of the metal fiber 10 in the X direction, and therefore the metal plate 25 can be utilized without waste. However, the invention is not limited to such a configuration, and the width W of the metal plate 25 needs only to be at least the length of the metal fiber 10 in the X direction. That is, the width W of the metal plate 25 may be greater than or equal to the length of the metal fiber 10 in the X direction. In the case that the width of the metal plate is greater than the length of the metal fiber, the shapes of the lower blade 21a of the die and the upper blade 22a of the punch 22 may be those that cut off excess portions from the ends of the metal fiber 10 in the X direction. A leading end 25a of the metal plate 2 prior to shearing is of a linear shape perpendicular to the length direction. Therefore, the leading end 25a is advanced toward the blade tips of the lower blade 21a of the die and the blade tips of the upper blade 22a of the punch for a width in the Y direction of the metal fiber to be cut out, and the punch is driven downward to shear the leading end 25a of the metal plate 25. Then, a cut piece 25b of the metal plate having the shape illustrated in B of FIG. 3 is cut off. Thereafter, if the metal plate 25 is advanced for a length in the Y direction corresponding to the width of the metal fiber and shearing is conducted by the punch 22, the metal fiber illustrated in B of FIG. 4 is cut out. The operations of intermittently advancing the metal plate 25 in the form of a band that extends in the Y direction at a pitch corresponding to the width in the Y direction of the metal fiber 10 and cutting the leading end of the metal plate 25 in the direction of advancement are repeated.
[0034] At this time, simultaneously with cutting the leading end of the metal plate 25 in the direction of advancement in the form of a wave with the punch 22 and cutting the ends 11 and 15 of the metal fiber 10 in the X direction with the cutting blade 22a of the punch 22, a pressing portion 22c inclined at an obtuse angle (FIG. 7 and FIG. 8) that protrudes in the Z direction from the lower surface 22b of the punch 22 presses the two ends of the metal fiber 10 in the Z direction, to plastically deform the two ends 11 and 15 at an obtuse angle. By this configuration, the metal fiber 10, of which the two ends 11 and 15 are bent in the Z direction, may be produced.
[0035] The lower surface 22b of the punch 22 is illustrated in detail in FIGS. 7 and 8. A of FIG. 7 illustrates the lower surface and B of FIG. 7 illustrates a front surface. Recesses 22e are formed in the side surfaces of the punch 22 as retaining recesses to be engaged by engaging portions provided in a punch plate for holding the punch 22. FIG. 8 is a perspective view of the punch 22, and illustrates the pressing portion 22c which is formed to protrude inclined at an obtuse angle from the lower surface 22b.
[0036] As is clear from the above description, the method and apparatus for producing a metal fiber of the invention intermittently advances the metal plate 25 in the form of a band in the Y direction at a pitch of the width in the Y direction of the metal fiber 10, cuts the leading end in the direction of advancement of the metal plate 25 with the punch 22 of the pressing machine into the shape of a wave, cuts the ends 11 and 15 in the X direction of the metal fiber 10, and simultaneously presses the metal fiber 10 in the Z direction with the pressing portion 22c that protrudes inclined at an obtuse angle in the Z direction from the lower surface of the punch 22. Thereby, the metal fiber 10 having the linear main body in the shape of a wave within the X-Y plane and is bent at an obtuse angle in the Z direction is produced simultaneously by a single descending operation of the punch 22.
[0037] Note that as a method for intermittently advancing the metal plate 25 in the Y direction at a pitch corresponding to the width in the Y direction of the metal fiber 10, as an alternative to controlling a conveying machine that advances the metal plate 25 such that the metal plate 25 is intermittently conveyed at the above pitch, the metal plate 25 may be conveyed with a weak force, the leading end 25a of the metal plate may be stopped at a cutting position by causing the leading end 25a to abut a stopper (not shown) embedded in the heel back 23, the metal plate 25 may be cut by the punch 22 at the cutting position, and then advancing the metal plate 25 for a length corresponding to the cut width at the weak force. In the case that the stopper is utilized, it is necessary for a clearance to be provided in the lower surface 22b of the punch 22 such that the punch 22 does not interfere with the stopper.
[0038] As illustrated in FIGS. 9 and 10, the apparatus for producing the metal fiber of the invention is provided with the heel back 23 that supports a rear surface 22d of the punch 22 from behind (23b) and guides the sliding vertical movement of the punch 22. A protrusion 23a is integrally formed on the upper portion of the heel back 23. The heel back 23 receives pressure of a reaction force from the lower blade 21a and the upper blade 22a when the punch 22 shears the metal plate 25, to enable smooth vertical movement of the punch 22.
[0039] Further, the operations of an apparatus for producing a metal fiber constituted by a linear main body in the form of a wave and extends only within an X-Y plane, that is, a metal fiber according to at least one embodiment of the invention which does not have a three dimensional shape, will be described with reference to FIG. 11 and FIG. 12. First, the configuration of the metal fiber according to at least one embodiment of the invention will be described with reference to FIG. 11. A through D in FIG. 11 illustrate the metal fiber according to at least one embodiment of the invention. As is clear from these drawings, the metal fiber 10 according to at least one embodiment of the invention extends from a first end 11 to a second end 15 and forms a linear main body in the form of a wave having an intermediate portion with a peak portion 12, a valley portion 13, and a peak portion 14 which are connected in this order between the first end 11 and the second end 15. The metal fiber 10 differs from the metal fiber according to at least one embodiment in the point that it does not have ends 11 and 15 which are bent in the Z direction at obtuse angles. Note that it goes without saying that the number of peak portions and valley portions is not limited to that of the example above, and may be increased or decreased according to intended uses. In addition, it also goes without saying that the size and the shapes of the bends of the metal fiber may be freely designed according to intended uses of one or more embodiments.
[0040] FIG. 12 illustrates a punch 22 of at least one embodiment of the invention. The punch 22 differs from the punch of previously discussed in the point that it does not have a pressing portion (element 22c in FIG. 7) that protrudes downward inclined at an obtuse angle in the Z direction on the bottom surface of the punch at the leading end in the X direction. Metal fibers constituted by linear main bodies in the form of a wave that extend within an X-Y plane can be produced, by applying this punch 22 in the production method of at least one embodiment.
REFERENCE NUMERALS
[0041] 10 metal fiber [0042] 11 end (bent portion) [0043] 12 peak portion [0044] 13 valley portion [0045] 14 peak portion [0046] 15 end (bent portion) [0047] 21 die [0048] 21a lower blade of die [0049] 22, 22 punch [0050] 22a upper blade of punch [0051] 22c pressing portion [0052] 23 heel back [0053] 25 metal plate
