JP3337800B2 - Shearing knife - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is capable of minimizing "burrs" and "burrs" on a cut surface, which are harmful when a metal strip such as a steel plate or a steel strip is continuously sheared in a longitudinal direction. The present invention relates to a simple shearing knife.

[0002]

2. Description of the Related Art Metallic forms such as steel plates and steel strips (hereinafter referred to as "metallic")
Conventionally, as a blade used for shearing a “steel plate”, a disk-shaped tool provided with a projection 3 protruding from an outer peripheral surface 4 at one end of an outer peripheral portion as shown in FIG. A knife 1 is used. This blade 1 is rotatably supported as an upper blade and a lower blade at a vertically symmetric position of a steel plate, and when a steel plate is inserted into the gap and sheared, a shear plane of the steel plate is shown in FIG.
As shown in the figure, the fracture surface g of the cut end of the steel plate 2 is increased,
Then, a “return” h occurs. This “burr” may fall off during the next processing, causing trouble. For example,
Since the dropped “burr” comes on the steel plate with a certain probability, if pressed in this state, there will be troubles of press flaws, and in severe cases, the “burr” will reach the press mold and Presses create scratches on everything. For these reasons, in recent years, there has been a strong demand for cut surfaces without “burrs”.

As a prior example for preventing "burring", Japanese Patent Publication No. Sho 54-30790 discloses a technique using a counterslit method using a cutting tool having an outer peripheral portion projected by combining a single blade and a flat blade. (Hereinafter referred to as “prior art 1”). Furthermore, Japanese Patent Application Laid-Open No. Sho 59-19621 reports a metal cutting method using a blade as shown in FIG. 2 (hereinafter referred to as "prior art 2").

[0004]

However, the prior art 1 has a drawback that the equipment cost is large because a knife and a masher roll are required.

In the prior art 2, since shearing is performed with a blade as shown in FIG. 2, a shearing load is concentrated on an a 'portion (projection 3) surrounded by a broken line in FIG. , Short lifespan (period of normal functioning). When the ratio between the height c of the protrusion 3 (the distance from the outer peripheral surface 4 in the radial direction of the blade 1 to the tip of the protrusion 3) and the thickness of the steel plate (the metal strip to be sheared) increases, Also, the fractured surface becomes larger, and the appearance is deteriorated, and “burrs” and “drips” occur. Therefore, the plate thickness at which a good shear surface can be obtained with the same blade has been limited to a narrow range.

In the recent shearing of thin steel plates and steel strips, it is strongly required that no "burrs" be present at the steel plate cut, so that trimming for removing the "burrs" has been necessary. For this reason, "burr" removal can be realized without performing trimming, and the same blade can be applied to a wide range of plate thicknesses. Furthermore, the long life of the blade improves the shearing operation efficiency. This is a necessary condition.

However, conventionally, as shown in Prior Art 1, large auxiliary equipment is required, or
With the blade shown in FIG. 2 and Prior Art 2, not only the life was short but also the shearing blade thickness applicable to the same blade was narrow.

Accordingly, an object of the present invention is to provide a shearing blade which can realize "burr" removal without performing trimming, can be applied to a wide range of plate thicknesses with the same blade, and can achieve a long life. It is in.

[0009]

SUMMARY OF THE INVENTION The present invention provides
In a cutting tool for shearing a metal strip, a metal strip to be sheared is provided at one end of an outer peripheral portion of a disk-shaped cutting tool (1) and provided in a circumferential direction of the cutting tool (1). Food
And a projection (3) for inserting
The blade (1) was provided on the inner base in the circumferential direction,
The end of the sheared metal strip is released to load the protrusion (3).
And a groove (5) for releasing the weight . Said groove (5) is characterized in that it has a triangular cross section with a gradually decreasing cross-sectional area towards its bottom. Further, the projection (3) extends from the outer peripheral surface (4) in the radial direction of the blade (1).
And the ratio of the distance b from the bottom of the groove (5) to the tip of the projection (3) in the radial direction of the blade (1) is 0.1 ≦ a / b ≦. 0.5. Further, the distance b is in the range of 0.5 to 2.5 times the plate thickness of the metal strip to be sheared.

Next, the reason why the shearing blade of the present invention is configured as described above will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing one embodiment of a shearing blade according to the present invention. As shown in FIG. 1, at one end of the outer peripheral portion of the blade 1, a protruding portion 3 protruding from the outer peripheral surface 4 is provided.
It is provided in the circumferential direction of the blade 1. A groove 5 is provided at the base of the protrusion 3 in the circumferential direction of the blade 1. The groove 5 is formed in a triangular cross-sectional shape whose cross-sectional area gradually decreases toward its bottom. The distance a (hereinafter, referred to as “a”) from the outer peripheral surface 4 to the tip of the protrusion 3 in the radial direction of the blade 1 and the protrusion 3 from the bottom of the groove 5 in the radial direction of the blade 1
Is the distance to the tip b (hereinafter, referred to as “b”).
It is in the range of 0.1 ≦ a / b ≦ 0.5. Also, b
Is in the range of 0.5 to 2.5 times the sheet thickness of the steel sheet (metal strip to be sheared).

The disk-shaped blades 1 and 1 having an outer peripheral surface 4, a projection 3 and a groove 5 as shown in FIG. 1 are rotatably supported as upper blades and lower blades at vertically symmetric positions of a steel plate (FIG. 1). 3), and when the steel plate 2 is inserted into the gap, A-
At the position A ′, the tips of the projections 3 of the upper and lower blades 1 make contact with the upper and lower surfaces of the steel plate 2 (see FIG. 4).

Next, at the position BB 'shown in FIG. 3, the tip of the projection 3 of the blade 1 is
Then, at the CC 'position shown in FIG. 3, the d portion corresponding to the position of the outer peripheral surface 4 also comes into contact with the steel plate 2 as shown in FIG. .

Next, at the position DD ′ shown in FIG. 3, while pushing the steel plate 2 at the d portion as shown in FIG. 7, the steel plate 2 is further cut into the steel plate 2 using the groove 5, and a shear surface is formed. .
FIG. 8 shows a partially enlarged view of this state. Further shearing is enabled by the end of the steel plate 2 escaping into the portion e in the groove 5 indicated by the broken line, and the load on the protrusion 3 is enabled by the escape of the end of the steel plate 2 to the e portion. Can escape.

Next, as shown in FIG. 3 and FIG.
At the position, a shear plane f is formed (see FIG. 11), and then a fracture plane g (see FIG. 11) is formed only at the FF ′ position as shown in FIGS. "Return" h
(See FIG. 11) occurs when this fractured surface is formed, but since the groove 5 is provided, the fractured surface can be made very small.

In the present invention, the provision of the groove 5 makes it possible to make the fracture surface extremely small. Therefore, the occurrence of “burrs” h is reduced, and the load of the plate edge of the steel plate is applied to the portion d shown in FIG. 8, so that “indentation” i occurs at the portion e (FIG. 1).
1), whereby the "burrs" h do not protrude from the front surface (or the back surface) of the steel plate.

Further, by the action of the groove 5, load concentration on the projection 3 can be avoided, and the service life of the blade can be extended.
Since the height of the protruding portion 3 can be made higher than that of the conventional one shown in FIG. 2 and the like, it is possible to have more sheared surfaces, so that a beautiful end face appearance can be obtained.

Further, since the shear load can be received in a large area by the groove 5, shearing is possible even if the lap allowance of the upper and lower blades is set to 0 (zero). By making the lap allowance “0” in this way, “who” j (see FIG. 11)
Can be very small.

The ratio of a to b is limited to the range of 0.1 ≦ a / b ≦ 0.5, and the height of b is limited to 0.5 to 2.5 times the thickness of the steel plate (metal strip). Is desirable. As a result, the blade is eliminated and the life of the blade is prolonged. If the height of b exceeds 2.5 times the plate thickness, or if a / b> 0.5, the force applied to the protrusion of the blade increases, and the strength of the protrusion cannot withstand this, and there is a possibility of breakage. On the other hand, if the height of b is less than 0.5 times the plate thickness, or if a / b <0.1, the above-described effects provided by the grooves 5 are insufficient.

[0020]

Next, the present invention will be described in more detail based on embodiments.

Example 1 A cutting tool of the present invention shown in FIG. 1 as a test piece, a cutting tool provided with a protruding portion at one end of an outer peripheral portion shown in FIG. 2 as a comparative example (hereinafter referred to as a "comparative cutting tool"), and As a conventional example, a flat blade-shaped blade (not shown) having a shape obtained by removing a protrusion from the comparative blade shown in FIG. 2 was used. In the blade of the present invention shown in FIG. 1, the value of b is 0.8 mm, and the value of a /
The value of b was 0.25 (the value of a was 0.2 mm). In the comparative knife shown in FIG. 2, the value of c was 0.2 mm. The steel plate was sheared by using a shearing device provided with these specimens as an upper blade and a lower blade. As described above, the thickness of the steel plate to be sheared was 0.5 mm because b of the blade of the present invention was 0.8 mm.
Applied to 0.4 to 1.6 mm within a range of ~ 2.5 times. For the comparative blade and the flat blade, a steel plate having a thickness of 0.4 to 1.6 mm was similarly sheared. The service life of each of the cutting tool of the present invention, the comparative cutting tool, and the flat cutting tool was examined by the following method. Table 1 shows the results. Table 1 also shows the amounts of "who", "return", and "indentation" generated by the implementation.

[0022]

[Table 1]

The methods for measuring "who", "return", and "indentation" were as follows. "Who" and "Kaeri"
Was measured using a method based on a cross-sectional photograph. FIG. 12 is a cross-sectional view illustrating a method for measuring “burrs”. As shown in FIG. 12, the positions of A and B were measured, and the amount of “burrs” generated (burrs height) was determined. In addition, during normal line operation, the measurement of “who” is not performed, but is merely visually confirmed. "Return" is 1/10 by micrometer
Measured at 0mm control. The "who", "burr" and "indentation" generation amounts were obtained and displayed as follows. Generated amount of each part ("Dare", "Kaeri" and "Indentation") / Thickness x 100%

Determination of the life of the blade (judgment of the end of life)
It carried out by the following method. Wear of the projections, and
It is determined that the life has expired when any of the blade cutting occurs. However, in recent years, the material of the trim blade has been diversified, and the refining method has been advanced. Therefore, before the end of the life due to the wear of the protruding portion, the blade is slashed (blanket).
This causes almost the end of life and the replacement of blades is almost 100%. When the blade is cut like this, the sharpness becomes poor, or a part of the blade jumps out of the cut. Note that the data of this embodiment regarding the determination of the service life of the blade is an average value of data for one year of the shearing operation. In addition, the length of life was shown by how many meters of steel plate (steel strip) could be sheared from the start of use of the blade to the end of life (abrasion of the protruding portion or occurrence of cutting).

As shown in Table 1, according to the knife of the present invention,
It can be seen that the life is significantly longer than that of the comparative knife.

In the case of the comparative knife, when the thickness of the sheared steel sheet was less than 0.6 mm and when it exceeded 1.0 mm, continuous shearing was impossible. That is, as shown in Table 1, the applicable plate thickness range which can be suppressed by the amount of "drool" and "burr" equivalent to that of the blade of the present invention is 0.6 to 1.0 m.
m and narrower than the blade of the present invention.

The flat blade does not have a projection, and the same range of the applicable plate thickness of 0.4 to 1.6 mm as that of the blade of the present invention is obtained. Quantity.

Example 2 Next, the relationship between the value of a / b and the life of the blade (0.1 ≦ a / b ≦ 0.5) was investigated.
Table 2 shows a / b when b of the blade of the present invention shown in FIG. 1 is fixed to 1.0 mm and the thickness of the steel plate is fixed to 0.8 mm (within the range of the present invention).
It is the result of investigating the relationship between the change in the value of the value and the service life of the blade.

[0029]

[Table 2]

As shown in Table 2, when the value of a / b is "a / b>0.5" which is out of the range of the present invention, there is a considerable possibility that the life of the blade will reach the end of the life before the end of the life due to the wear of the blade. growing.

Next, the steel plate was sheared using a blade having an a / b value of 0.7 out of the range of the present invention. FIG. 14 shows a / b
The life ratio between the wear life and the actual life (blade) when the steel sheet was sheared 10 times (n = 10) using a blade with a value of 0.7 out of the range of the present invention (actual life / wear life) FIG. The circles in the figure indicate the life ratios. As shown in FIG. 14, eight out of ten uses have a life due to cutting, and those with a life ratio of 100% (protrusion wear) are 2%.
Times (n = 3, 6). The average life ratio of the test 10 times was only 67%. Thus, a / b>
At 0.5, the force applied to the protrusions of the blade is increased, and the strength of the protrusions cannot withstand this, which may result in breakage.

On the other hand, when the value of a / b is within the range of the present invention, 0.1 ≦ a / b ≦ 0.5, it can be seen that the life of the blade is longer than when the value is outside the above range. That is, 0.1 ≦ a / b
When .ltoreq.0.5, if the height of b in FIG. 1 is set to 0.5 to 2.5 times the plate thickness, the life due to the blade cutting is unlikely, and the life ratio becomes almost 100%, indicating that the blade can be used until worn. .

[Embodiment 3] Next, the blade of the present invention used in the embodiment 1 is replaced with a steel plate having a thickness outside the range of the present invention (distance b is out of the range of 0.5 to 2.5 times the thickness of the steel plate). A case where the present invention is applied to shearing will be described.

In Example 1, the thickness of the shearable steel plate of the blade of the present invention is in the range of b × 0.5 to 2.5 (b = 0.8 mm).
0.4 mm to 1.6 mm (within the range of the present invention). Therefore, using this blade, a steel sheet having a thickness of 0.3 mm and 2.2 mm (outside the scope of the present invention) is sheared, and the “shape”, “burr”,
The amount of "indentation" and the life of the blade were investigated. Table 3 shows the results.

[0035]

[Table 3]

From Table 3, the following results were found. When the thickness is 0.3 mm (b> (thickness × 2.5)): b in FIG.
(B = 0.8mm) height is 2.5 times the plate thickness (0.3mm × 2.5 =
0.75mm), the cutting ends only at the tip of the projection,
The shear surface has no fracture surface (g in FIG. 11). This is because there is no shearing state after FIG. 6, and there is no indented part (i in FIG. 11), and the “burrs” jump out to the lower part (outside the plate surface shown in FIG. 13, hereinafter referred to as “lower part”). And
A shear surface without "burrs" cannot be obtained. In addition, since the entire shear load was applied only to the projections, it was predicted that the plate thickness would be thin and the service life would be long, but the service life was shorter than the plate thickness of 0.4 mm.

When the plate thickness is 2.2 mm (b <(plate thickness × 0.5
): When the height of b (b = 0.8 mm) in FIG. 1 is less than 0.5 times the plate thickness (2.2 mm × 0.5 = 1.1 mm), the ratio of the shear surface (f in FIG. 11) by the projections of the present invention is small. And the fracture surface becomes large. In the case of shearing with this blade, the “burr” increases as the fracture surface increases, and “burr height> indentation height”
Then, the "burr" jumps out at the bottom, making it impossible to burr without shearing. From the above results, it can be seen that the shearable plate thickness is in the range of 0.5 to 2.5 times b.

[0038]

As described above, according to the present invention, it is possible to carry out shearing without burr (burr-free trimming) with less expensive equipment than the counter slit method, and to provide a groove having only a conventional projection. As compared with a blade having no blade, cutting is less likely to occur, the life of the blade is lengthened, the frequency of replacement is reduced, and an industrially useful effect is provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a shearing blade of the present invention.

FIG. 2 is a longitudinal sectional view showing one example of a conventional shearing blade.

FIG. 3 is a side view showing a shearing state of the shearing blade of the present invention.

FIG. 4 is a sectional view taken along line A-A ′ of FIG. 3;

FIG. 5 is a sectional view taken along line B-B ′ of FIG. 3;

FIG. 6 is a sectional view taken along line C-C ′ of FIG. 3;

FIG. 7 is a sectional view taken along line D-D 'of FIG.

FIG. 8 is an enlarged view of a part (e part) of FIG. 7;

9 is a sectional view taken along line E-E 'of FIG.

FIG. 10 is a sectional view taken along line F-F 'of FIG.

FIG. 11 is a side view showing a shear plane of a steel plate sheared by the cutting tool of the present invention.

FIG. 12 is a cross-sectional view for explaining a burr measurement method.

FIG. 13 is a side view showing a burr.

FIG. 14 is a graph showing the results of an investigation on the life ratio.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 blade 2 steel plate 3 protrusion 4 outer peripheral surface 5 groove a distance from outer peripheral surface in the radial direction of blade to tip of protrusion a ′ part where shear load acts intensively b protrusion from bottom of groove in radial direction of blade C Distance from the outer peripheral surface in the radial direction of the blade to the tip of the protrusion d Position of the outer peripheral surface e Part in the groove f Shear surface g Fracture surface h Kaeri i Indentation j

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshikatsu Suehiro 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Inside Nippon Kokan Co., Ltd. (72) Michi Takahira 2-10-4 Nachigaoka, Natori City, Miyagi Prefecture (72) Inventor Takeo Matsuura 1-11-15 Chisaka Tosaka, Higashi-ku, Hiroshima-shi, Hiroshima Prefecture (56) References JP-A-58-202711 (JP, A) JP-A-52-72620 (JP, U) (58) Fields investigated ( Int.Cl. ⁷ , DB name) B23D 19/00 B26D 1 / 14,1 / 24

Claims (4)

(57) [Claims] A blade for shearing a metal strip is provided at one end of an outer peripheral portion of a disk-shaped blade (1) so as to protrude beyond an outer peripheral surface (4) and to be provided in a circumferential direction of the blade (1). , Sheared
A protrusion (3) for cutting into the metal strip; and an end of the metal strip to be sheared , which is provided at a base inside the protrusion (3) in a circumferential direction of the cutting tool (1), and releases the protrusion. Department
(3) A shearing blade having a groove (5) for releasing a load to the cutting blade. 2. A shearing knife according to claim 1, wherein said groove has a triangular cross section whose cross-sectional area gradually decreases toward its bottom. 3. A distance a from the outer peripheral surface (4) in the radial direction of the blade (1) to a tip of the projection (3);
The ratio of the distance b from the bottom of the groove (5) to the tip of the protrusion (3) in the radial direction of the blade (1) is 0.1 ≦ a / b ≦ 0.5. The cutting blade for shearing according to claim 1 or 2, wherein 4. The method according to claim 1, wherein the distance b is 0. 0 of the thickness of the metal strip to be sheared.
The shearing knife according to claim 3, wherein the ratio is within a range of 5 to 2.5 times.