JPH01146610A - Manufacturing device for metallic short fiber having excellent adhesion and dispersibility - Google Patents

Abstract

PURPOSE:To provide short fiber with a linear part and two end curved parts and to improve adhesion and dispersibility, by a method wherein either upper or lower blade is formed with an inclination part extending from a central part toward ends on both sides and having an angle with a horizontal plane and inclination parts at end parts on both sides extending in succession to the former inclination part. CONSTITUTION:Each slit material 13 cut by a slitter device 5 is conveyed on a lower blade 9 of a shearing device 7, and when the tip thereof is protruded by a given distance, an upper blade 8 is lowered. A horizontal part 15 and edge cut parts 12 of a central cut part 10 of an upper blade 8 press a central part 13b and end parts 13a on both sides of the slit material 13. The slit material 13 is sheared from the central part 13b toward the end parts 13a on both sides by means of the horizontal part 15 and first and second inclination parts 16a and 16b of the central cut part 10, and a tensile force exerted from the central part toward the outside is exerted to form a linear part. Meanwhile, the slit material is sheared from the end parts 13a on both sides to the inside by means of third and fourth inclination parts 17a and 17b of the edge cut parts 12, and is pressed inwardly downward with a force to form a closed loopform curved part. A metallic short finer provided at a central part with a linear part and o end parts on both sides with closed loopform curved parts is provided.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an apparatus for producing linear short metal fibers used in fiber-reinforced concrete. This invention relates to the structure of a shearing blade that prevents entanglement and improves dispersibility.

[Conventional technology]

In general, concrete materials used for civil engineering and construction materials have a 0.5
Linear short metal fibers of about φ×30 size, for example, steel fibers, are mixed in a volume percentage of about 1 to 2%. By the way, when the above-mentioned short metal fibers are mixed into concrete in a straight state, they have poor adhesion.
For example, there is a problem that when a tensile load is applied to concrete, it may come loose and reduce its strength. Therefore, it has been conventionally known to form bent portions or liquid portions at both ends of the short metal fibers by, for example, roll processing or rolling processing (see Japanese Patent Publication No. 52-47051.53-12278).
Also, bell-shaped or U-shaped bent parts are formed at both ends of the wire (see Japanese Patent Publication No. 15-2071) to improve the adhesion between short metal fibers and concrete. Various proposals have been made.

However, the methods for producing short metal fibers described in the above-mentioned publications require large-scale roll equipment and rolling equipment to form bent parts and liquid parts in the thin plate, which increases equipment costs and manufacturing costs. rises.

Furthermore, when wire rods are used, the unit price is higher than that of thin sheets, so there is a problem in that the product cost is also high from this point of view.

On the other hand, in the method for manufacturing short metal fibers described in Japanese Patent Publication No. 55-16768, the fixed blade in the part where the thin plate comes into contact is formed into a wave shape, and the shearing force of the rotary blade is used to create a wave-shaped metal fiber. This method is used to obtain short fibers. According to this, since the fixed blade is formed into a wave shape, there is no need for processing equipment to form the above-mentioned bent portions and liquid portions, and since the thin plate is sheared into a linear shape, the equipment cost is reduced. Material unit costs can be reduced, and product costs can be reduced accordingly.

However, with the above-mentioned wave-shaped fixed blade, since the rotating blade hits the thin plate at right angles at once, the shearing load tends to increase, and in order to reduce this load, the length of the short metal fibers has to be shortened, resulting in poor adhesion. There's a problem. This is especially true in the case of a high-strength steel fiber made of, for example, a high-tensile steel plate, which results in insufficient adhesion.

Therefore, in order to solve the above-mentioned conventional problems, the inventors of the present invention developed a manufacturing method as shown in FIGS.
The fibers are sheared inward from both ends 20a in the width direction to obtain arc-shaped short metal fibers 21, 22, and 23. Also, both sides of the thin plate 20 in the width direction @2
Shearing is started substantially at the same time from 0a and the center portion 20b to obtain short metal fibers 24 having arcuate ends and a substantially straight center portion.

By embedding the arc-shaped short metal fibers 21 to 24 in concrete, even if tension is applied, the bent portions will become caught and difficult to remove (adhesion can be improved. Since it is possible to process circular arc parts,
There is no need for secondary processing equipment to form liquid parts, etc. at both ends, and the product cost can be reduced accordingly. Furthermore, since the shearing blades do not come into contact with each other all at once, the shearing load can be reduced and short metal fibers of desired length can be obtained, and from this point of view as well, adhesion can be improved.

[Problem that the invention seeks to solve]

Incidentally, although the above-mentioned arc-shaped short metal fibers improve adhesion, when mixed into concrete, the arc portions of the short metal fibers may become entangled with each other and become lumpy, resulting in poor dispersibility. be. This is thought to be due to the fact that the arcuate portion is in an open loop shape, which causes the short metal fibers to become entangled when being stirred. Therefore, in order to prevent the above-mentioned entanglement, as shown in FIG. Loss may occur due to increased weight relative to the length of the fiber,
The radius of curvature of the spiral portion 25 increases, which may cause voids to occur in the concrete, making it difficult to employ.

An object of the present invention is to provide an apparatus for producing short metal fibers that can reduce manufacturing costs, improve adhesion, and improve dispersibility while avoiding an increase in weight and generation of pores.

[Means for solving problems]

Therefore, the present invention provides an apparatus for producing linear short metal fibers by moving the upper and lower blades up and down to shear a strip-shaped thin plate in the width direction at predetermined intervals in the longitudinal direction. one of the blades extends from the center of the thin plate toward both ends,
The first blade forms an angle θ1 in the opposite direction to the other blade with respect to the horizontal plane. a second inclined portion; The first slope is formed to be located at both ends of the thin plate following the second slope. The angle θ with the second slope is (900-01) < θ8 (
180'''-θt).

Here, the shearing blade sets the angle θ1 and the angle θ8 within the ranges of 2 to 30 degrees and 60 to 120 degrees, respectively, and the shear blade has a contact point between the first and third inclined portions and a second inclined portion.
It is desirable that the distance #l connecting the contact point of the inclined part and the fourth inclined part be in the relationship W-10m≦1<W with respect to the width W of the thin plate, and A horizontal portion or a gently curved portion may be formed between the 24th TI4 inclined portion and the first to fourth inclined portions may be formed repeatedly at predetermined intervals.

[Effect]

According to the apparatus for manufacturing short metal fibers according to the present invention, the upper blade or the lower blade has the first and second inclined parts that form an angle θ1 in the opposite direction to the other blade with respect to the horizontal plane along the shearing direction of the thin plate. , followed by the third one which is inclined towards the other blade side. Since the thin plate sheared by the blade is composed of the fourth inclined part, the thin plate sheared by the first inclined part is A substantially linear portion corresponding to the second inclined portion, followed by the third inclined portion. It is formed into a linear short metal fiber having a small-diameter closed-loop curved portion corresponding to the fourth inclined portion. That is, the first blade of the above blade. The second inclined portion connects the central portion of the thin plate to the third inclined portion. The fourth inclined portion presses both ends of the thin plate at the same time, so that the central portion of the thin plate presses the first inclined portion at a small angle θ.
．． Since it is pulled outward by the second slope, it is sheared into a substantially straight line. On the other hand, since both ends of the thin plate are pressed inward by the 3rd and 41st diagonal parts at a large angle θ, they are curved into an arc due to shear strain, and the tips of these are brought into contact with the straight part. As a result, a closed loop is formed. In this case, the above angle θ
The larger the diameter, the smaller the curved portion is formed. Since both ends of the short metal fibers formed in this way are curved in a closed loop shape, these curved parts are securely anchored to the concrete, improving adhesion and preventing it from coming off due to tensile and bending loads. .

In addition, since the curved part forms a closed loop, it will not become entangled even if it is stirred in the concrete.
As a result, dispersibility can be improved. Furthermore, the curved portion is
- Since it is formed into a shape with a small radius of curvature, it is possible to avoid loss due to increased weight and generation of pores in the concrete compared to a spiral shape.

Furthermore, in shearing the thin plate, since the inclined blade is pressed into contact with the thin plate, the blade surface does not contact the thin plate over its entire length at once, so the shearing load can be reduced.
Since the length of the short metal fibers can be ensured accordingly, adhesion can be improved from this point of view as well, and manufacturing costs can be reduced since secondary processing equipment can be omitted.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 to 6 are diagrams for explaining an apparatus for producing short metal fibers according to an embodiment of the present invention.

In the figure, reference numeral 1 indicates a manufacturing apparatus for short metal fibers, which is mainly composed of an uncoiler 2 for unraveling a coiled 88 plate 3, a slitter device 5, and a press device 6. The slitter device 5 includes a pinch roller 4 for conveying the thin steel plate 3, and a pair of slitter rolls 1) each having a cutter formed on its outer circumferential surface. This is a device that cuts the material into a predetermined width, for example, every 30 cranes, along the longitudinal direction, and forms a large number of slit materials 13. Further, the press device 6 is a device that cuts each slit material 13 from the slitter device 5 in the width direction to form linear short metal fibers of about 0.50 x 30 fins. Note that the large one is a packet for collecting short metal fibers.

Further, the press device 6 is provided with a shearing device 7 for cutting the slit material 13, and the shearing device 7 mainly includes an upper blade 8 that moves up and down in the vertical direction, and a flat plate that is fixed in a horizontal state. The lower blade 9 has a sharp blade surface 9a. The upper blade 8 is slightly inclined so that the tip thereof faces forward in the conveying direction of the slit material 13, and when the upper blade 8 is lowered, it faces forward in the conveying direction with a predetermined gap between it and the lower blade 9. It is installed so that it is located at

The blade surface 8a of the upper blade 8 has a roughly wavy shape in which center notches 10 and edge notches 12 are alternately formed over the entire length thereof.

Here, since the waveform of the blade surface 8a repeats the same shape for each width of the slit material 13, the l-pit component thereof will be explained in detail below.

The central cut portion 10 includes a horizontal portion 15 located at the center portion 13b in the width direction of the slit material 13, and a first inclined portion 16a and a second inclined portion extending from the horizontal portion 15 toward both ends 13a of the slit material 13. 16b, and the above-mentioned 1. The second inclined portions 16a and 16b form an angle θ within a range of 2 to 30 degrees with respect to the horizontal portion 15.

Further, the edge notch portion 12 includes the first inclined portion 16
It is comprised of a third inclined part 17a formed following the above-mentioned second inclined part 16b, and a fourth inclined part 17b formed subsequent to the second inclined part 16b. Also, this third. Fourth (ll oblique part 17a
, 17b are located at both ends 13a of the slit material 13, and the third inclined part 17a and the fourth inclined part 17b
are the first inclined portion 16a and the second inclined portion 16, respectively.
It is formed at an angle θ8 within a range of 60 to 120 degrees with respect to b.

Here, the reason why the angle θ1 is set within the range of 2 to 30 degrees is that the smaller the angle θ1 is, the straighter the metal short fibers will be, so the dispersibility can be improved. The shearing load applied to the blade becomes large, which is unfavorable in terms of the life of the blade.From these points, it is preferable to set the angle θ within the above range of 2 to 30 degrees.

is set within the range of 60 to 120 ft in order to satisfy the condition that the curved portion of the short metal fiber can be formed into a small diameter closed loop shape, which will be described later.
If the angle is 20 degrees or more, the adhesion effect cannot be obtained and the curved portion may become loop-like, so a range of 60 to 120 degrees is appropriate. In this case, the larger the angle θ, the smaller the angle θ2, and (90°−〇,)〈θ〈(180°−θ
Angle θ5 that satisfies the relationship I). It is necessary to select θ2.

Further, a contact point a between the first inclined part and the third inclined part and a second inclined part are provided.
It is desirable that the distance l connecting the contact point between the inclined part and the fourth inclined part has a relation of W-10<l<W with respect to the width W of the slit material 13 indicated by L. This is due to the above-mentioned angle θ1. θ8,
It depends on the shear width, the material and plate thickness of the slit material 13, but for example, in the case of steel fiber for boat fishing, the strength is 70 kg/
t, shape 0゜5t
The width of the slit material 13 is W-34m, 1)-3Q.

Next, the effects of this embodiment will be explained.

First, the outline of the manufacturing process by the manufacturing apparatus 1 will be explained. The thin steel plate 3 wound into a coil is conveyed by a pinch roll 4, and is cut by a slitter device 5 into a predetermined width to form a plurality of band-shaped slit materials 13. Each slit material 13 is then conveyed to the press device 6 and sheared in the width direction of the slit material 13 by the shearing device 7 to become linear short metal fibers 18, which are housed in the packet 14.

Next, the process of shearing the slit material 13 using the shearing device 7 will be explained with reference to FIGS. 5 and 6.

The slit material 13 conveyed onto the lower blade 9 of the shearing device 7
When the tip of the upper blade 8 is projected forward by a predetermined amount, the upper blade 8 is lowered in synchronization with this conveyance speed. Then, the horizontal portion 15 and the edge notch portions 12 of the central notch portion 10 of the upper blade 8 press the central portion 13b and both ends 13a of the slit material 13. As a result, the slit material 13 becomes
The horizontal portion 15 of the central notch 10 and the first . The second inclined portions 16a and 16b shear from the central portion 13b toward both ends 13a. In this case, the central portion 13b of the slit material 13 has an angle θ.

The first step is to Since the downward pushing force by the second (IJI diagonal parts 16a and 16b acts) and the pulling force directed outward from the center part acts, a substantially straight straight part tea is first formed.On the other hand, The slit material 13 is sheared inward from both ends 13a by the third and fourth inclined parts 17a and 17b of the edge notch 12. In this case, the slit material 13 is sheared inward from both ends 13a.
is the third point forming an angle θ8. Since it is strongly pressed inward and downward by the fourth inclined parts 17a and 17b, a closed loop curved part 18b is formed by this shear strain. As a result, short metal fibers 18 having a straight portion 18a at the center and closed-loop curved portions 18b at both ends are obtained.

In this way, according to this embodiment, the upper blade 8 is connected to the slit material 1.
3 at an angle θ1 with respect to the horizontal plane along the shear direction of the first .
2nd iTI4 oblique portions 16a, 16b and the following angle θ
Part 3 of 8. Since it is composed of the fourth inclined parts 17a and 17b, the slit material 13 sheared by the upper blade 8 is
Above 1st. A straight portion 18a corresponding to the second inclined portions 16a, 16b, followed by the third. 4th (1) Oblique section 17
A closed loop small diameter curved portion 18b corresponding to a and 17b
A linear short metal fiber 18 is obtained, and the curved portion 18b improves adhesion to concrete, and as a result, it does not come off even when embedded in concrete, and the tensile strength can be improved. .

Further, since the short metal fiber 18 of this embodiment has a straight portion 18a and a closed loop curved portion 18b,
Even when mixed in concrete, they do not get entangled, and as a result, dispersibility can be improved.

Furthermore, since the curved portion 18b can be formed in a single layer with a small diameter, it is possible to avoid loss due to an increase in weight and generation of pores in the concrete compared to the case where the curved portion 18b is formed in a spiral shape. Moreover, since both ends of the curved portion 18b are deeply curved inward, it is possible to prevent accidents such as being stuck when handled by the operator by hand, and it also has the effect of making it possible to pack it into a plastic bag when packing. be.

Furthermore, the blade surface 8a of the upper blade 8 is formed in a wave shape, and since the blade surface 8a does not contact the slit material 13 over the entire length at the same time, the shearing load can be reduced, and the length of the short metal fibers can be reduced accordingly. Since the blade surface 8a can be secured, adhesion can be improved from this point of view as well, and the life of the blade surface 8a can be extended. Furthermore, since the curved portion 18b can be formed at the same time as shearing, manufacturing costs can be reduced by omitting secondary processing equipment.

In the above embodiment, the upper blade 8 has the first to fourth inclined parts 16.
16b, 17a, and 17b, but of course they may be formed on the lower blade 9 and the upper blade 8 made flat, and in this case, the same effect as in the above embodiment can be obtained. be.

Further, in the above embodiment, the case where the upper blade is one piece has been explained, but the present invention can of course be applied to other shearing devices. For example, it may be adopted as a rotary blade of a rotary shearing machine. This device is equipped with a large number of rotating blades around the outer periphery of the body, feeds a thin plate onto a fixed blade, and shears it by the rotation of the rotating blades to produce short metal fibers. In this case as well, substantially the same effects as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the apparatus for producing short metal fibers with excellent adhesion and bidispersity according to the present invention, either the upper or lower blade is connected to the first blade which forms an angle θ with respect to the horizontal plane. a second slope part;
Part 1. Since it is composed of the second (lI inclined part) and the third and fourth inclined parts forming an angle θ8, a short metal fiber having a straight part and a closed loop curved part can be obtained, so that both adhesion and dispersibility are improved. Not only does it have excellent effects, but it also has the effect of reducing shear load, avoiding increase in weight and generation of pores, and reducing product cost by omitting secondary processing.

[Brief explanation of the drawing]

Figures 1 to 6 show adhesion 1 according to an embodiment of the present invention.
1 is a schematic configuration diagram showing the manufacturing apparatus for short metal fibers with excellent dispersibility; FIG. 2 is a perspective view showing the manufacturing process; FIG. Fig. 3 is a front view showing the upper and lower blades of the shearing device, Fig. 4 is a side view thereof, Fig. 5 is a front view showing the upper blade in contact with the slit material, and Figs. Figure 6 (C1 is a plan view showing the sheared state of the slit material, Figure 6+d+ is a front view showing the metal short fiber obtained by shearing, Figure 7f)
Figures al to 7 fcl are plan views showing short metal fibers for explaining the process of establishing the present invention, and Figure 8 (al
and FIG. 8 (bl is a plan view showing other short metal fibers,
FIG. 9 is a diagram showing other short metal fibers. In the figure, 7 is a shearing device (a manufacturing device for short metal fibers);
8 is the upper blade, 9 is the lower blade, 13 is the slit material (thin plate), 13
a is both ends of the slit material, 13b is the center, 16a, 1
6b is the first. The second inclined portions 17a and 17b are the third and fourth inclined portions, respectively, and 18 is the short metal fiber, θ3. θ
8 is an angle and the patent applicant is Kobe Steel Co., Ltd. Representative Patent Attorney Tsutomu Tsutomu Figure 3 Figure 4 Figure 6

Claims (5)

[Claims] (1) By moving either the upper blade or the lower blade up and down, the strip-shaped thin plate conveyed between the upper and lower blades is sheared in the width direction at predetermined intervals in the longitudinal direction to produce linear short metal fibers. In the apparatus for manufacturing, one of the upper and lower blades extends from the center of the thin plate toward both ends, and has first and second slopes that form an angle θ_1 in the opposite direction to the other blade with respect to the horizontal plane. and the angle θ_2 formed with the first and second inclined parts is (90°-θ_1)<θ_2<( 180°-θ
An apparatus for producing short metal fibers with excellent adhesion and dispersibility, characterized by comprising third and fourth inclined portions that satisfy the relationship _1). (2) The above θ_1 is 2 to 30 degrees, and θ_2 is 60 to 30 degrees.
12. The apparatus for producing short metal fibers with excellent adhesion and dispersibility according to claim 1, wherein the angle is 120 degrees. (3) The distance l connecting the contact point between the first inclined part and the third inclined part and the contact point between the second inclined part and the fourth inclined part is W-10 mm≦with respect to the width W of the thin plate. An apparatus for producing short metal fibers with excellent adhesion and dispersibility according to claim 1 or 2, characterized in that l<W. (4) Adhesiveness according to any one of claims 1 to 3, characterized in that there is a horizontal part or a gently curved part between the first slope part and the second slope part. , manufacturing equipment for short metal fibers with excellent dispersibility. (5) The first to fourth inclined portions of the upper blade or the lower blade are repeatedly formed at predetermined intervals, according to any one of claims 1 to 4. Equipment for producing short metal fibers with excellent adhesion and dispersibility.