JPH09295271A - Cutting blade and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict the generation of noise and vibration during the cutting work as much as possible by adhering plural boards to each other through a metal layer having an internal void or a metal layer having a void in a grain boundary. SOLUTION: A metal layer 12 as an adhesive layer is formed between two circular steel plates 11a and 11b, and the steel plates 11a, 11b are adhered to each other through a clearance 14 so as to form a base board 11. Voids 13a, 13b are formed in the metal layer 12, and this void 13a is formed in the metal powder, and the void 13b is formed in the grain boundary of the metal powder. Thereafter, a grinding grain layer 16 is fixed to the peripheral part of the base board 11 by cold pressing, and burned at the predetermined temperature in a sintering furnace so as to alloy the grinding grain layer 16 for adhesion. With this structure, generation of noise and vibration during the cutting work can be remarkably restricted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting blade used for a portable electric tool, a portable engine cutter, etc. used for cutting concrete or stone materials.

[0002]

2. Description of the Related Art Conventionally, a cutting device such as a portable electric tool or a portable engine cutter has been used for cutting concrete or stone. Various cutting blades such as a diamond cutter are attached to these cutting devices according to the object to be cut, and the cutting work is performed.

When cutting concrete or the like using a cutting device such as a portable electric tool, large noise and vibration are generated during the work, which adversely affects not only the operator and the cutting device but also the surroundings.

In order to deal with this, the structure of the cutting blade itself has been devised so far, and various cutting blades having a structure for suppressing vibration and noise generated during cutting work have been developed. Such cutting blades are disclosed, for example, in Japanese Utility Model Publication No. 58-70869 and Japanese Utility Model Publication No.
No. 9-128358, Japanese Utility Model Laid-Open No. 5-85547, and Japanese Patent Laid-Open No. 59-107860.

The blade disclosed in Japanese Utility Model Laid-Open No. 58-70869 has a structure in which a plurality of steel plates are stacked and bonded together with an adhesive.

In the cutting grindstone substrate disclosed in Japanese Utility Model Laid-Open No. 59-128358, an intermediate plate made of a different material is sandwiched between two outer plates, and these are integrated by spot welding.

The cutting blade disclosed in Japanese Utility Model Laid-Open No. 5-85547 has a substrate formed by bonding two steel plates together, and an annular groove concentric with the substrate is provided on the bonding surface of the substrate. There is.

In the disk for diamond cutter disclosed in Japanese Patent Laid-Open No. 59-107860, a plurality of steel plates are metallurgically bonded via an intermediate layer (metal or alloy) having a low Young's modulus.

These cutting blades are structurally slightly different from each other, and each of them has an abrasive grain layer and a substrate fixed to each other by brazing or laser welding. By virtue of the laminated structure or the provision of an air layer between these metal plates, the vibration generated during the cutting work is damped and the overall vibration is suppressed.

[0010]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Shokai 58-7086
In the blade disclosed in Japanese Patent No. 9, the resin of the adhesive is deteriorated by the heat during brazing, and the noise suppressing effect is reduced. Further, in the simultaneous sintering method, since the abrasive grain layer is usually sintered at a high temperature of 800 ° C. or higher, the adhesive burns and the blade cannot be applied to the simultaneous sintering method.

In the cutting grindstone substrate disclosed in Japanese Utility Model Laid-Open No. 59-128358, the side faces of the steel plates constituting the substrate are usually finished by lathe or polishing, so that two steel plates are simply combined together. No air gap is formed for noise attenuation. For this reason, two steel plates are bonded by spot welding to form a void in a portion other than the portion integrated by spot welding, but the spot welding requires time and labor and is expensive. Further, since the spot-welded portion is integrated, vibration propagates from this portion and the noise damping effect is small.

In the simultaneous sintering method, since heating is performed during sintering, the substrate is deformed and distorted due to the difference in thermal expansion coefficient between the abrasive layer and the substrate. In order to suppress this distortion, the substrate must be rolled in a firing mold during sintering. At this time, in the case of the cutting grindstone substrate, since the voids other than the spot welds are also integrated by rolling, the noise suppressing effect is lost. Further, the spot welds are deteriorated by heat during sintering, and the strength is reduced.

Further, the cutting blade disclosed in Japanese Utility Model Laid-Open No. 5-85547 requires a lathe or the like to form an annular groove concentric with the substrate, which requires time and labor. High cost. In the simultaneous sintering method, distortion of the substrate occurs due to sintering, but in the cutting blade, since there is a concentric circular groove, a large substrate distortion occurs especially in this portion, and it is difficult to remove this distortion. Is.

In the diamond cutting disk disclosed in Japanese Patent Laid-Open No. 59-107860, the strength of the substrate may decrease due to the presence of the intermediate layer having a low Young's modulus. In order to deal with this, the substrate may be thickened, but if the substrate is thickened, the abrasive grain layer also needs to be thickened, resulting in poor machinability, which is not practical. Further, even if the intermediate layer is provided, the entire steel sheet is adhered and there are no voids, so the noise suppressing effect is low.

As described above, the conventional cutting blade does not have a sufficient noise suppressing effect and cannot be manufactured by the simultaneous sintering method. Since the simultaneous sintering method can simultaneously sinter the abrasive grain layer and bond it to the substrate, the number of steps can be reduced and the cost can be reduced as compared with the method of bonding the abrasive grain layer and the substrate by brazing or laser welding. is there. In addition, since the adhesive strength is stronger and safer than the brazing method and the like, there is a demand for a cutting blade that can be manufactured by the simultaneous sintering method and has a high sound deadening effect.

Therefore, an object of the present invention is to provide a cutting blade which has a high effect of suppressing noise and vibration and which can be manufactured by the simultaneous sintering method.

[0017]

In order to solve the above problems, the present invention relates to a cutting blade in which an abrasive grain layer is fixedly formed by a sintering method on the outer peripheral portions of a plurality of substrates which are arranged facing each other with a space therebetween. The plurality of substrates are adhered by a metal layer having internal voids, a metal layer having voids at grain boundaries, and a metal layer having both of these voids.

Since the shock generated during the cutting operation is transmitted as vibration from the blade edge of the blade to the substrate, the vibration transmitted from the blade edge to the substrate is amplified in the conventional substrate and a large noise is generated. In the cutting blade of the present invention, the substrate is a structure in which a plurality of metal plates are bonded together, and since these metal plates are bonded by a metal layer having internal voids or a metal layer having voids at the grain boundaries, the abrasive The metal layer, which is not deactivated even by the sintering heat of the grain layer and has a void, serves as a cushion for weakening the transmission of the vibration and damps the vibration.
Further, between the metal plates, there is a void larger than that in the metal in a portion where the metal layer as the adhesive is not present, and therefore, a synergistic action of this void and a minute void in the metal layer occurs during cutting work. Highly effective in damping vibration.

Here, the metal layer can be arranged in any of a dot shape, a concentric circle shape, a spiral shape, a radial shape, or a combination thereof. Among the metal plates constituting the substrate of the cutting blade of the present invention, various patterns can be considered for the arrangement of the metal layers, but any of dot, concentric, spiral, radial, or a combination thereof is arranged. By doing so, there is an effect that an optimum noise suppression effect can be provided according to the cutting conditions.

3 kHz when the metal layers are arranged in dots
Since it is highly effective in suppressing noise of a high frequency of about 10 kHz, it is effective when performing a cutting operation with a shallow depth of cut using a high-speed machine.

When arranged concentrically, 1.5 kHz
Since it is highly effective in suppressing noise of a medium frequency of up to 8 kHz, it is effective when cutting a stone or the like using a stationary machine that generates a strong noise in a specific frequency component.

When arranged in a spiral, 1.0 kHz
Since the effect of suppressing noise in a wide range of frequencies up to 9 kHz is high, it is effective when cutting various work materials using a hand-held power tool.

When arranged radially, 0.5 kHz to
Since it is highly effective in suppressing noise of a low frequency of 4 kHz, it is effective when performing a deep-cutting work using a low-rotation machine.

Further, by arranging the metal layers in a dot, concentric, spiral, or radial combination state, the advantages of each arrangement can be compounded, so that a wide range of frequencies from low frequencies to high frequencies can be obtained. Highly effective in suppressing noise including noise.

Here, the size of the voids in the metal layer is 1
μm to 40 μm is desirable. The noise and vibration generated during the cutting work by the cutting blade may vary depending on the material of the object to be cut, but the frequency is about 0.5 kHz to 10 kHz.
Since the frequency is about Hz, by setting the size of the voids interposed in the metal layer in the range of 1 μm to 40 μm, particularly in the range of 6 μm to 20 μm, noise and vibration at this frequency can be effectively damped. The size of the voids present in the metal layer can be changed by changing conditions such as the particle size of the metal powder, the mixing ratio, and the difference in sintering temperature from the abrasive grain layer.

The internal porosity of the metal layer is 1% to 30%.
Is desirable. If the porosity is too high, the amount of the adhesive is relatively small, so that the adhesive force is reduced. If the porosity is too low, the vibration is transmitted as it is, so that the noise and vibration damping effects are reduced.
Therefore, the porosity is in the range of 1% to 30%, particularly 5% to
If it is within the range of 15%, the adhesive strength is not lowered,
Excellent noise and vibration damping effects can be obtained.

The metal powder for forming the metal layer, which forms the internal voids or the grain boundary voids by the heat of sintering in the simultaneous sintering method, must have a sintering temperature higher than that of the abrasive grain layer.
Cobalt powder, copper powder, nickel powder, tin powder, tungsten powder, or mixtures thereof can be used.

Since the cobalt powder has a low bulk density, it is possible to increase the amount of voids in the metal layer. The copper powder contains a large amount of voids between the metal particles and thus has a high vibration damping effect. A vibration damping effect is produced by forming intercalation compounds and changing the natural frequency.

Further, since tin powder has a low melting point, it is in a completely molten state near the sintering temperature, moves into other metal powder, and at the same time coats the surface of the other metal powder, Glue each other. Therefore, the original place where the tin powder was present is changed to a void. Also,
Coating the surface of another metal powder with tin having a low Young's modulus also serves to enhance the vibration damping effect.

Furthermore, since the tungsten powder plays a role of a bridge by containing the tungsten powder,
There is an auxiliary effect of stabilizing the size of the voids present in the metal layer.

Further, the metal powder is characterized by being produced by either a reduction method or an electrolysis method. Examples of the metal powder produced by the reduction method include cobalt powder, nickel powder, tungsten powder, and titanium powder, which are characterized by fine powders that are combined in a chain. As the metal powder produced by the electrolytic method, there are copper powder and silver powder, which are characterized in that they are dendritic, have a large specific surface area, and are excellent in formability and sinterability.

At this time, the average particle diameter of the metal powder is from 1 μm to
By setting the thickness to 40 μm, noise and vibration damping effects are enhanced, and the effect that the thermal deformation generated on the substrate in the blade manufacturing process can be corrected by hammering is obtained.

The cutting blade sprays an adhesive agent on one of the opposing surfaces of the substrates arranged to face each other while masking unnecessary portions, and sprinkles metal powder on the adhesive agent to fix the adhesive. While the substrates are arranged facing each other, the abrasive grain layer is fixed to the outer peripheral portion of the same substrate by cold press, and these are fired in a firing furnace to firmly form the abrasive grain layer and to react the metal powder. It is possible to manufacture by forming a void inside and bonding the plurality of substrates.

In the simultaneous sintering method, since the abrasive grain layer can be sintered and adhered to the substrate at the same time, the number of steps can be reduced and the cost is lower than the method of adhering the abrasive grain layer and the substrate by brazing or the like. In addition, the adhesive strength is stronger and safer than the brazing method.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 is a front view of a cutting blade according to a first embodiment, FIG. 2 is a sectional view taken along line XX of FIG. 1, FIG. 3 is a block explanatory view showing a manufacturing process of the cutting blade shown in FIG.
FIG. 4 is a graph showing the result of noise measurement during cutting.

In FIGS. 1 and 2, 10 is a cutting blade, 11 is a substrate, 11a and 11b are steel plates constituting the substrate 11, 12 is a metal layer, 13a and 13b are voids in the metal layer 12, and 14 is a steel plate 11a. The gap between the and 11b, 16
Is an abrasive grain layer.

In the cutting blade 10 of this embodiment, a metal layer 12 which is also an adhesive layer is formed between two disc-shaped steel plates 11a and 11b.
The substrate 1 is bonded to the substrate 1b with a gap 14 interposed therebetween.
1 is formed. Further, in the metal layer 12, voids 13a,
Although there is 13b, the voids 13a are voids in the metal powder, and the voids 13b are voids in the grain boundaries of the metal powder.

The impact generated during the cutting operation by the cutting blade 10 is transmitted as vibration from the abrasive grain layer 16 to the substrate 11, but the voids 13a, 13b, 14 serve as cushions for weakening the transmission of vibration. Damps vibration. In particular, the voids 13a and 13b in the metal layer 12 prevent the propagation of vibration and are excellent in the vibration damping effect as compared with the conventional one. As a result, the vibration and noise generated during the cutting work are significantly reduced as compared with the conventional one.

In the cutting blade 10, as shown in FIG. 1, the metal layer 12 is adhered to the portion (belly) that is moving by vibration, so that the noise suppressing effect is high, and the metal layer 12 itself is small. However, the effect of damping the vibration was remarkable.

In the cutting blade 10, the metal layer 1
Since 2 are arranged concentrically around the rotation axis, 1.
As a result, the effect of suppressing noise at a medium frequency of 5 kHz to 8 kHz is high. The place where the metal layer 12 is arranged is an effective portion obtained by analyzing the vibration mode.

Here, in the cutting blade 10, the average diameter of the internal voids 13a interposed in the metal layer 12 is 6 μm, and the average diameter of the voids 13b at the grain boundaries is 20 μm. Noise and vibration generated during the cutting work by the cutting blade 10 differ depending on the material of the object to be cut, etc., but since the frequency is about 0.5 kHz to 10 kHz, the average diameter of the voids 13a is set to 6 μm and the grain boundary is reduced. Void 13
By setting b to 20 μm, noise and vibration in this range could be effectively damped. The metal layer 12
The size of the intervening voids can be changed by changing the manufacturing conditions such as the particle size of the metal powder, the mixing ratio, and the difference in sintering temperature from the abrasive grain layer.

The porosity of the metal layer 12 is 5% to 15%.
And If the porosity in the metal layer 12 is 15% or more, the amount of the adhesive is relatively small and the adhesive force is reduced, and if the porosity is 5% or less, the vibration is easily transmitted as it is, and the noise and the vibration are attenuated. The effect decreases. Therefore, by setting the porosity within the range of 1% to 30%, particularly 5% to 15%, excellent noise and vibration damping effects were obtained without impairing the adhesive force.

In the cutting blade 10, the metal layer 12 between the steel plates 11a and 11b forming the substrate 11 is formed by the simultaneous sintering method.
27.5%, copper 25% to 30%, nickel 30% to 35
%, Tin 5% to 10%, and tungsten 5% to 10%. With such a mixing ratio, it is possible to stably secure the effective voids 13a and 13b by sintering at a temperature suitable for the abrasive grain layer 16. However, since the kind and the mixing ratio of the metal powder are not limited to these, other metal powders can be used or the mixing ratio can be changed.

Further, since the metal powder forming the metal layer 12 is produced by the reduction method and the electrolysis method, a large amount of voids are contained in the powder and the sound deadening effect is high.
In addition, it is also possible to use the metal powder produced by the atomizing method or the pulverizing method. In that case, since it is necessary to increase the voids in the grain boundaries of the metal powder, irregularities such as needle-like and angular shapes are possible. It is desirable to select a metal powder having a different shape. By setting the average particle size of the metal powder forming the metal layer 12 to 20 μm, noise and vibration can be effectively suppressed, and deformation caused by heat generated in the substrate in the blade manufacturing process can be corrected by hammering. The effect was obtained.

Next, a method of manufacturing the cutting blade 10 will be described with reference to FIG. As shown in FIG.
First, the steel plates 11a and 11b are manufactured (40), and the steel plate 11
Metal powder is temporarily adhered to the facing surfaces of a and 11b (41), and the both are bonded to form the substrate 11. Specifically, steel plate 1
On the opposing surfaces of 1a and 11b, the adhesive unnecessary portion is masked, the adhesive is sprayed only on the necessary portion, and the metal powder is scattered on this to fix the metal powder in the adhesive. Separately from this, the abrasive layer is prepared (42).

Thereafter, the abrasive grain layer 16 is fixed to the outer peripheral portion of the substrate 11 by cold pressing (43), and these are fired at a predetermined temperature in a sintering furnace (44). As a result, the abrasive grain layer 16 is alloyed, and the abrasive grain layer 16 is bonded to the outer peripheral portion of the substrate 11. At this time, the surface of the metal powder between the steel plates 11a and 11b is also activated, and the steel plates 11a and 11b are melted and diffused.
Since it adheres to the b-side, minute and uniform voids 13a and 13b are simultaneously formed in the metal layer 12.

After this, the substrate 11 produced by sintering
(45) and then paint the substrate 11 (4)
6) The abrasive layer 16 is polished (47). Then, the finished cutting blade 10 is packed (48) and shipped (49).

As described above, in the cutting blade 10, the adhesion between the substrate 11 and the abrasive grain layer 16 around the substrate 11 and the metal layer 12 are performed.
By performing simultaneous formation of the above, it was possible to inexpensively provide a cutting blade having a high noise suppressing effect and excellent safety. It should be noted that this manufacturing process is the same as the conventional manufacturing process for a diamond cutter or the like by the simultaneous sintering method, and since special equipment is not required, it has a wide range of applications and is low in cost.

Next, the cutting test results by the cutting blade 10 will be described. As shown in Table 1, a cutting test was performed using a cutting blade 10 (NO1) and two types of cutting blades (NO2, NO3) for comparison. The dimensions of each cutting blade and the substrate structure are as shown in Table 1. The conditions of the cutting test are as shown in Table 2.

[0050]

[Table 1]

[0051]

[Table 2]

When the above cutting test was performed and the noise during cutting was actually measured, the results shown in FIG. 4 were obtained. From this graph, the noise generated when the cutting blade 10 (NO1) is cut has a sound pressure of 91 dB, and the other two types of cutting blades (NO2, NO3) have 97% noise respectively.
It can be seen that it is the smallest when compared with dB and 99 dB.

Since noise and vibration can be suppressed in the cutting work by the cutting blade 10, not only the burden on the operator and the cutting device is reduced, but also the adverse effect on the surroundings is reduced, which is effective in improving the working environment. is there.

Next, the cutting blade 20 of the second embodiment will be described with reference to FIG. In the cutting blade 20, the metal layer 21 containing the metal powder is spirally arranged on the substrate 22. The structure of the other parts is exactly the same as that of the cutting blade 10 described above. By arranging the metal layer 21 containing the metal powder in a spiral shape, 1.0 k
The effect of suppressing noise in a wide range of Hz to 9 kHz is high, and it is effective when cutting various work materials with a hand-held electric tool.

Next, the cutting blade 30 of the third embodiment will be described with reference to FIG. In the cutting blade 30, the metal layer 31 containing metal powder is sandwiched between the substrates 32 in a dot shape. The structure of the other parts is exactly the same as that of the cutting blade 10 described above. By arranging the metal layer 31 containing the metal powder in a dot shape, 3.0 kHz to
Highly effective in suppressing high-frequency noise of 10 kHz,
This is effective when making shallow cuts with a high-speed machine.

[0056]

According to the present invention, the following effects can be obtained.

(1) By adhering the substrate of the cutting blade with a metal layer having internal voids or voids at grain boundaries, noise and vibration during the cutting operation can be significantly suppressed.

(2) Since the cutting blade of the present invention can be manufactured by the simultaneous sintering method, the manufacturing process is simple.

(3) Since the cutting blade of the present invention is bonded by the metal layer formed by the simultaneous sintering method, it has a strong adhesive force and is safe.

[Brief description of drawings]

FIG. 1 is a front view showing a cutting blade according to a first embodiment.

FIG. 2 is a cross-sectional view near XX in FIG.

FIG. 3 is an explanatory view showing a manufacturing process of the cutting blade shown in FIG.

FIG. 4 is a graph showing the result of noise measurement during cutting.

FIG. 5 is a front view showing a cutting blade according to a second embodiment.

FIG. 6 is a front view showing a cutting blade according to a third embodiment.

[Explanation of symbols]

 10, 20, 30 Cutting blade 11, 22, 32 Substrate 11a, 11b Steel plate 12, 21, 31 Metal layer 13, 13a, 13b, 14 Void 16 Abrasive grain layer

Claims (7)

[Claims] 1. A cutting blade comprising an abrasive grain layer fixedly formed on a peripheral portion of a plurality of substrates arranged facing each other through a space by a sintering method, the metal layer having internal voids or the metal having voids at grain boundaries. A blade for cutting, wherein the plurality of substrates are adhered by a layer. 2. The cutting blade according to claim 1, wherein the metal layer is one of a dot shape, a concentric circle shape, a spiral shape, a radial shape, or a combination thereof. 3. The size of the voids in the metal layer is from 1 μm to
The cutting blade according to claim 1, which has a thickness of 40 μm. 4. The cutting blade according to claim 1, wherein the porosity in the metal layer is 1% to 40%. 5. The cutting blade according to claim 1, wherein the metal powder forming the metal layer contains at least one of cobalt powder, copper powder, nickel powder, tin powder, and tungsten powder. 6. The cutting blade according to claim 1, wherein the metal powder is produced by either a reduction method or an electrolysis method. 7. An adhesive is sprayed on one of the facing surfaces of the facing substrates while the unnecessary portion is masked, metal powder is sprinkled and fixed onto the adhesive, and then the facing substrates are placed facing each other. In this state, the abrasive grain layer is fixed to the outer peripheral portion of the substrate by cold pressing, and the abrasive grain layer is fixedly formed by firing these in a firing furnace, and the metal powder is reacted to form voids inside. And a method for manufacturing a cutting blade for adhering the plurality of substrates together.