JP6903528B2 - Cutting blade - Google Patents

Description

The present invention relates to a cutting blade used for cutting asphalt, reinforced concrete, stone, etc. at a work site in the civil engineering and construction industry.

As a cutting blade used for cutting asphalt and reinforced concrete at a work site in the civil engineering and construction industry, for example, there is one as shown in FIG. The cutting blade 50 is formed by fixing segment chips 51 formed by sintering diamond abrasive grains with metal powder to the outer periphery of a disk-shaped substrate 52 at regular intervals. Further, in the outer peripheral portion of the substrate 52, slits 53 are provided between the segment chips 51 and 51 adjacent to each other in the circumferential direction of the substrate 52, respectively.

The side view shape of the slit 53 may be U-shaped, but in order to alleviate the stress concentration at the bottom of the slit, conventionally, as shown in FIG. 10, the bottom of the slit 53 (the portion near the center of the substrate 52) is formed. A so-called "key slit" provided with a round hole 54 is widely used.

On the other hand, as a conventional cutting blade characterized by a slit in a substrate like the cutting blade according to the present invention, for example, there are cutting blades described in Patent Documents 1 and 2. In the cutting blade described in Patent Document 1, the round hole at the bottom of each slit is made into an elliptical hole, and the curvature of the bottom of the slit is increased to improve the function of relaxing stress concentration. However, if the bottom of the slit has such a structure, the stress concentration position when an external force is applied tends to occur on the small diameter side of the ellipse having the smallest curvature, so that it cannot be said to be effective in preventing the occurrence of cracks.

Further, in the cutting blade described in Patent Document 2, the noise generated when the cutting blade idles is reduced by providing a noise reduction hole extending in the rotation direction of the cutting blade at the bottom of each slit. .. With this slit shape, the sound pressure in the 2 KHz jarring frequency range included in the wind noise during idling is reduced, which is effective as a noise countermeasure.

However, in the cutting blade described in Patent Document 2, since the noise reduction hole of the slit has a shape that penetrates to the lower rear portion of the chip with respect to the rotation direction of the blade, the rigidity of the substrate at the rear portion of the chip is lowered, and the cutting operation is performed. The chip itself vibrates inside, and the noise during cutting work is not much different from that of general cutting blades.

Japanese Unexamined Patent Publication No. 2007-160416 Japanese Unexamined Patent Publication No. 2015-39760

Generally, in cutting work on asphalt roads and the like, a self-propelled cutting machine equipped with an engine that rotationally drives a cutting blade on a trolley that can move along the road surface is used. The cutting depth in the cutting work by such a self-propelled cutting machine depends on the thickness of the asphalt layer, but is about 10 cm to 60 cm, and the groove portion formed in the asphalt layer during the cutting work is the groove. It is characterized by a deep groove depth relative to the width.

In cutting work using a self-propelled cutting machine, cooling water is supplied to the cutting part, but in order to improve the efficiency of water injection to the processing point, cooling water is supplied from the spindle spindle, which occurs when the cutting blade rotates. A method of injecting water using centrifugal force is common.

The sludge water mixed with chips generated during the cutting work is sucked by the vacuum device attached to the cover of the cutting machine and collected in the specified place. In recent years, the performance of the cutting blade has been improved and the horsepower of the cutting machine has been increased. Since the cutting speed is increased due to the conversion, the amount of chips discharged increases compared to the amount of cooling water supplied, and the problem of leftover chips is a problem.

Generally, the cooling water used for a self-propelled cutting machine is stored in a tank, placed on a transport vehicle, carried to the work site, and supplied to the cutting machine using a pump, so the total amount of water that can be supplied is Limited to the capacity of the cooling water tank. Therefore, as a means for solving the above problem, it is conceivable to increase the supply amount of cooling water, but there is a limit to this, and if the supply amount of cooling water is increased, the cutting distance becomes relatively short. Therefore, it cannot be said to be an effective means.

In the conventional cutting blade 50 shown in FIG. 10, since the slit shape is a "key slit", the cooling water discharged from the spindle (not shown) is transmitted to the side surface of the substrate 52 by centrifugal force and the cutting edge (segment tip). It flows toward the outer peripheral side of the 51), but when it flows into the round hole 54 of the slit 53, the flow of the cooling water is hindered at the stepped portion where the round hole 54 and the straight portion 53 are joined, and a part of the cooling water is a substrate. Since it flows into the side surface of the 52 and stays at the step at the joint between the segment chip 51 and the substrate 52, the cooling water supplied from the pump is not efficiently supplied to the vicinity of the processing point.

As a result, the amount of cooling water supplied to the chips is reduced, the concentration of sludge is increased, and the suction force of the vacuum device for the chips is relatively insufficient, so that chips remain in the cutting groove or the vacuum device is used. There is a problem that chips adhering to the inner surface fall and a large sludge mass accumulates on the road surface.

On the other hand, in the cutting blade described in Patent Document 1, an elliptical hole is provided at the bottom of the slit, and in the cutting blade described in Patent Document 2, a noise reducing hole extending in the rotation direction of the cutting blade is provided at the bottom of the slit. However, since these slits do not have the function of efficiently guiding the cooling water to the cutting edge, it is not possible to eliminate the leftover chips generated during the cutting operation.

Therefore, an object to be solved by the present invention is to provide a cutting blade capable of efficiently guiding cooling water to the cutting edge and having an excellent chip discharge function.

In the cutting blade according to the present invention, a plurality of segment chips are arranged at regular intervals on the outer periphery of a disk-shaped substrate, and the outer periphery of the substrate is placed on the substrate between the segment chips adjacent to each other in the circumferential direction of the substrate. A cutting blade having a slit that is open on the side, has a concave shape toward the center of the substrate, and has a pair of linear inner edges facing the circumferential direction of the substrate.
The slit is a portion in which the width of the slit, which is the distance between a pair of linear inner edges facing each other in the circumferential direction of the substrate, continuously decreases from the bottom side of the slit toward the opening end side. The side view shape of the bottom of the slit (the shape seen from the direction perpendicular to the side surface of the substrate) forms a part of a circle inscribed in the pair of inner edges, and the inner edge and the bottom of the slit It is characterized in that there are no irregular curved surfaces or stepped portions at the boundary portion of, and the surface is smoothly continuous. Here, the "slit width" refers to the dimension of the slit in the circumferential direction of the substrate (the distance between the inner edges in the circumferential direction of the substrate).

In the case of the cutting blade, of the pair of inner edge portions facing each other along the circumferential direction of the substrate in the slit, the inner edge portion located behind the rotation direction of the cutting blade is parallel to the radial direction of the substrate. Can be done.

In the case of the cutting blade, it is desirable that the angle formed by the pair of inner edges facing each other along the circumferential direction of the substrate in the slit is 10 to 50 degrees.

If the angle is less than 10 degrees, a sufficient flow velocity cannot be obtained to increase the water pressure of the cooling water, and if the angle exceeds 50 degrees, the cooling water that has flowed into the slit flows out from the opening end of the slit. It is desirable that the angle is 10 to 50 degrees, because the resistance to the water injection increases and the water injection efficiency decreases.

The cutting blade may be provided with a plurality of types of slits having different distances from the opening end to the bottom of the slit.

In the cutting blade, it is desirable that the opening width of the opening end of the slit is 1.5 mm to 5 mm.

If the opening width is less than 1.5 mm, the slit is too narrow, the resistance of the water flow increases, it becomes impossible to supply a sufficient water flow to the cutting edge, and the mixed state of the chips and the cooling water tends to deteriorate. If the opening width exceeds 5 mm, the efficiency of increasing the flow velocity of the cooling water decreases, and only the same performance as that of the conventional U-shaped slit can be obtained. Therefore, the opening width is 1.5 mm to 5 mm. It is desirable to have.

In the cutting blade, it is desirable that the side view shape of the bottom of the slit forms a part of a circle having a diameter of 5 mm to 12 mm.

If the diameter is less than 5 mm, the volume of the slit portion becomes small, and the amount of cooling water supplied from the spindle and flowing along the side surface of the substrate to the slit becomes small, so that the amount supplied to the cutting edge becomes insufficient. If the diameter exceeds 12 mm, the distance to the adjacent slits in the rotation direction becomes short, so that the rigidity of the substrate is insufficient when a force is applied to the segment chip in the direction intersecting the side surface of the substrate, resulting in problems such as bending. Is likely to occur, so the diameter is preferably 5 mm to 12 mm.

According to the present invention, cooling water can be efficiently guided to the cutting edge, and a cutting blade having an excellent chip discharge function can be provided.

It is a side view which shows the cutting blade which is an embodiment of this invention. It is a partially enlarged view of the cutting blade shown in FIG. It is a partially enlarged view of the vicinity of the slit of the cutting blade shown in FIG. It is an end view at the line AA in FIG. It is a partially omitted vertical cross-sectional view which shows the cutting operation by the cutting blade shown in FIG. It is a chart which shows the dimension and other data of the cutting blade used for a cutting test. It is a chart which shows the cutting test result. It is a side view which shows a part of the cutting blade which is another embodiment. It is a side view which shows a part of the cutting blade which is another embodiment. It is a side view which shows a part of the conventional cutting blade.

Hereinafter, the cutting blades 100, 200, and 300 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 9.

First, the cutting blade 100 will be described with reference to FIGS. 1 to 7. As shown in FIGS. 1 to 4, in the cutting blade 100, a plurality of segment chips 11 are arranged at regular intervals on the outer periphery of the disk-shaped substrate 10, and the segment chips 11, 11 adjacent to each other in the circumferential direction of the substrate 10 are arranged. The substrate 10 between the substrates 10 has a slit 12 having an opening on the outer peripheral side of the substrate 10 and a concave shape toward the center 10c of the substrate 10. The cutting blade 100 includes a portion where the width 12w of the slit 12 is continuously reduced from the bottom portion 12b side of the slit 12 toward the opening end 12a side. Hereinafter, the slit 12 may be referred to as a "nozzle type slit" as opposed to the conventional "key slit".

In each slit 12, of the pair of linear inner edge portions 12c and 12d facing each other along the circumferential direction of the substrate 10, the inner edge portion 12c located on the rear side in the rotation direction R of the cutting blade 100 is the substrate 10. It is parallel to the radial direction 10r. The width 12w of the slit 12 means the dimension of the slit 12 in the circumferential direction of the substrate 10 (the distance between the inner edges 12c and 12d in the circumferential direction of the substrate 10).

The angle 12θ formed by the pair of inner edge portions 12c and 12d facing each other in each slit 12 can be arbitrarily set within the range of 10 degrees to 50 degrees, but in the present embodiment, the inner edge portions 12c and 12d of the slits 12 The forming angle 12θ is set to 15 degrees.

The opening width 12e of the opening end 12a of each slit 12 can be arbitrarily set within the range of 1.5 mm to 5 mm, but in the present embodiment, the opening width 12e is set to 3 mm.

As shown in FIG. 3, the side view shape of the bottom portion 12b of the slit 12 (the shape seen from the direction perpendicular to the side surface of the substrate 10) forms a part of the circle C inscribed in the inner edge portions 12c and 12d. Specifically, as shown in FIG. 3, when the slit 12 is viewed from the side, the circle C appears as two straight lines that continuously widen from the opening end 12a side toward the center 10c side (see FIG. 1). It is inscribed in parts 12c and 12d. That is, the circle C corresponds to the inscribed circle of the inner edge portions 12c and 12d whose side view shapes form two straight lines.

At the boundary between the inner edges 12c and 12d and the bottom 12b, there are no discontinuous portions such as curved surfaces and steps, and they are smoothly continuous. The diameter 12f of the circle C can be arbitrarily set within the range of 5 mm to 12 mm, but in the present embodiment, the diameter 12f of the circle C is set to 8 mm.

As shown in FIG. 5, when the asphalt road D is cut using the cutting blade 100, the cooling water supplied from the spindle shaft (not shown) travels along the side surface of the substrate 10 due to centrifugal force to the outer periphery. It flows to the side and flows from the bottom 12b of each slit 12 toward the opening end 12a as shown by the arrow line W. The width 12w of the slit 12 is from the bottom 12b side of the slit 12 to the opening end 12a side. Since it is a "nozzle type slit" having a portion that continuously decreases toward, the flow velocity of the cooling water is greatly accelerated in the process of the cooling water flowing in the slit 12 toward the opening end 12a side. The water pressure when discharged from the opening end 12a rises sharply, and the cooling water flows into the processing point P with intense pressure.

As a result, the chips and sludge generated in the vicinity of the processing point P and the cooling water are sufficiently mixed and quickly recovered by the vacuum device (not shown). Therefore, chips do not remain in the cutting groove M, or the chips adhering to the inner surface of the vacuum device do not fall and a large sludge mass does not accumulate on the asphalt road D.

As described above, the cutting blade 100 includes the slit 12 which is a "nozzle type slit" having a width 12w which is continuously reduced from the bottom portion 12b side of the slit 12 toward the opening end 12a side. , Cooling water can be efficiently guided to the cutting edge during the cutting operation, and chips generated at the machining point P or the like can be efficiently discharged.

Next, based on FIGS. 6 and 7, the cutting blades "developed product 1" and "developed product 2" according to the embodiment of the present invention and the cutting blades to be compared are "comparison 1" to "comparison 4". The contents of the cutting experiment conducted for "" and the results thereof will be described.

The dimensions and other data of the cutting blade (evaluation blade) used in the experiment are as shown in FIG. L, T, and X in "dimensions: 18" x 40L x 3.6T x 12X x 30N "described in FIG. 6 indicate the dimensions of each part of the segment chip 11 shown in FIGS. 2 and 4, respectively. , N indicate the number of segment chips 11 arranged on the outer periphery of the substrate. Further, the “angle”, “opening width”, “bottom diameter” and “depth” shown in FIG. 6 are the “angle θ”, “opening width 12e”, “diameter 12f” and “diameter 12f” shown in FIG. 3, respectively. It represents "depth 12g".

The cutting blades related to "Development product 1" and "Development product 2" and the cutting blades related to "Comparison 1" to "Comparison 4" are attached to the bogie type cutting machine, respectively, and the work material is used based on the following cutting conditions. A piece of asphalt was cut.
Blade rotation speed: 3000m / min
Notch: 15 cm
Cutting distance: 200m / blade

The results of the cutting experiment using each cutting blade shown in FIG. 6 described above are as shown in FIG. 7, respectively. "Development product 1" and "Development product 2" have good water circulation to the cutting edge during cutting work, and have improved cleanability and cooling performance on the surface of the segment tip, and are of the conventional "key slit" type shown in FIG. The cutting speed was improved by 10 to 20% as compared with the cutting blade 50. Further, since the "developed product 1" and the "developed product 2" are sufficiently mixed with the chips and the cooling water during the cutting operation and are stably collected by the vacuum device, the chips in the cutting groove are collected. There was almost no clogging or residue of chips.

In the conventional product "Comparison 1", the cutting groove was clogged with chips, and the chips adhering to the machine occasionally accumulated as lumps on the road surface. In addition, a streak in the circumferential direction can be seen on the side surface of the substrate at the boundary between the circular portion of the "key slit" and the portion where the linear inner edge portion faces, and a part of the cooling water is blocked from the flow of the substrate. A phenomenon of flowing to the side surface occurred.

In "Comparison 2", since the opening end of the slit is narrow, the amount of cooling water supplied to the cutting edge is insufficient, causing clogging and spouting chips.

In "Comparison 3", the cutting speed was the same as that in "Comparison 1", but the pressure of the cooling water was not sufficiently improved, and the cutting groove was clogged with chips.

"Comparison 4" has a structure in which the opening end of the slit of "Comparison 2" is widened, but the opening width of the opening end of the slit is too wide for the amount of the supplied cooling water, so that the pressure is improved. The water storage effect was insufficient, the mixing effect of chips and cooling water was reduced, and chips were clogged in the cutting groove.

On the other hand, the cutting blades "developed product 1" and "developed product 2" according to the embodiment of the present invention have good water circulation to the cutting edge portion and do not cause clogging of chips as described above. It was.

Next, the cutting blades 200 and 300, which are other embodiments of the present invention, will be described with reference to FIGS. 8 and 9. In the cutting blades 200 and 300, the parts common to the cutting blades 100 shown in FIGS. 1 to 5 are designated by the same reference numerals as those in FIGS. 1 to 5 and the description thereof will be omitted.

In the cutting blade 200 shown in FIG. 8, the angle 22θ formed by the inner edges 22c and 22d of the slit 22 is 45 degrees, the diameter 22f of the bottom 22b of the slit 22 is 11 mm, and the opening width 22e of the opening end 22a of the slit 22 is 3 mm. The depth of the slit 22 from the opening end 22a to the bottom 22b is set to 21 mm.

As shown in FIG. 8, in the cutting blade 200, the side view shape of the slit 22 is largely narrowed from the bottom portion 22b toward the opening end 22a. Therefore, during the cutting operation, the opening end of the slit 22 is formed. The water pressure of the cooling water discharged from the 22a is higher than that of the cutting blade 100 shown in FIG. 1, and the mixing efficiency of the chips and the cooling water is increased, so that the chip discharge function is excellent.

Next, in the cutting blade 300 shown in FIG. 9, a plurality of types of slits 12 and 32 having different depths from the opening end to the bottom of the slits and angles formed by facing inner edges are formed along the outer peripheral direction of the substrate 10. They are arranged alternately. The depth 12g from the opening end 12a of the slit 12 to the bottom 12b is larger than the depth 32g from the opening end 32a to the bottom 32b of the slit 32. Further, the angle 12θ formed by the opposing inner edge portions 12c and 12d of the slit 12 is smaller than the angle 32θ formed by the opposing inner edge portions 32c and 32d of the slit 32.

In the cutting blade 300 shown in FIG. 9, since the bottoms 12b and 32b of the slits 12 and 32 adjacent to each other in the circumferential direction of the substrate 10 are separated from each other, bending between the slits 12 and 32 of the substrate 10 is performed. The strength is increased, and it becomes difficult for slanting to occur during cutting work such as asphalt.

The cutting blades 100, 200, 300 described with reference to FIGS. 1 to 9 exemplify the cutting blades according to the present invention, and the cutting blades according to the present invention are the above-mentioned cutting blades 100, 200, 300. Not limited to.

The cutting blade according to the present invention can be widely used in industrial fields such as the civil engineering and construction industry as a tool for cutting work such as asphalt, reinforced concrete, and stone.

10 Substrate 10c Center 10r Radial direction 11 Segment chips 12, 22, 32 Slits 12a, 22a, 32a Opening ends 12b, 22b, 32b Bottom 12c, 12d, 22c, 22d, 32c, 32d Inner edge 12e, 22e Opening width 12f, 22f Diameter 12g, 22g, 32g Depth 100, 200, 300 Cutting blade 12θ, 22θ, 32θ Angle C Circle D Asphalt road M Cutting groove P Machining point

Claims (6)

A plurality of segment chips are arranged at regular intervals on the outer periphery of the disk-shaped substrate, and the outer peripheral side of the substrate is opened in the substrate between the segment chips adjacent to each other in the circumferential direction of the substrate, and the center of the substrate is opened. A cutting blade having a concave shape toward the substrate and having a slit having a pair of linear inner edges facing each other in the circumferential direction of the substrate.
The slit is a portion in which the width of the slit, which is the distance between a pair of linear inner edges facing each other in the circumferential direction of the substrate, continuously decreases from the bottom side of the slit toward the opening end side. The side view shape of the bottom of the slit (the shape seen from the direction perpendicular to the side surface of the substrate) forms a part of a circle inscribed in the pair of inner edges, and the boundary between the inner edge and the bottom of the slit. A cutting blade that is smoothly continuous with no curved surfaces or steps. The first aspect of the slit, wherein the inner edge portion of the pair of inner edge portions facing the circumferential direction of the substrate, which is located on the rear side in the rotation direction of the cutting blade, is parallel to the radial direction of the substrate. Cutting blade. The cutting blade according to claim 1 or 2, wherein in the slit, an angle formed by a pair of inner edges facing each other along the circumferential direction of the substrate is 10 to 50 degrees. The cutting blade according to any one of claims 1 to 3, further comprising a plurality of types of slits having different distances from the opening end to the bottom of the slit. The cutting blade according to any one of claims 1 to 4, wherein the opening width of the opening end of the slit is 1.5 mm to 5 mm. Cutting blade according to claim 1 in which the side surface view shape of the bottom of the slit forms part of a circle having a diameter 5Mm～12mm.

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