JP2008272860A - Single layer diamond wheel and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting or grinding single layer diamond wheel for minimizing a spark. <P>SOLUTION: A diamond grain 2 is brazed and fixed to a surface of a substrate 1 via an Ni brazing filler metal 3, and next, fine spherical glass beads are injected into the diamond grain 2 and a brazing filler metal 3 surface by a blast device, and the brazing filler metal 3 surface is smoothly formed, and the brazing filler metal of the surface of the diamond grain 2 is removed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a diamond wheel that is mainly attached to a portable grinder or the like and suppresses the generation of sparks as much as possible.

  As an example, in periodic inspections of nuclear power plants, cutting, grinding, or cutting operations are often performed in operations such as piping, support structures, and gantry repairs. However, in such a power plant building, it is necessary to take thorough fire prevention measures. For this purpose, the work area is covered with a non-combustible sheet, and cutting or grinding work is performed so that no sparks are emitted from the area. This is because resinoid grinding wheels are mainly used for cutting steel materials, and sparks are violently generated when deburring, roughing, pipe beveling or cutting.

During this operation, the abrasive grains and the binder are gradually dropped and new abrasive grains appear, so that cutting or the like is continued. For this reason, abrasive grains, binders and chips are generated as dust, and the working environment is deteriorated, and the cutting powder is released in the form of needles and easily pierces the operator's gloves. Therefore, sufficient protective gear and caution were required.
Japanese Patent Laid-Open No. 10-2117006

In the work area of the building, it has been desired to reduce the sparks as much as possible and to prevent the abrasive grains from dropping and the binder from falling off during the cutting and grinding work, thereby improving the working environment.
Then, this invention makes it a subject to solve the problem which concerns.

The present invention according to claim 1 is a single-layer diamond wheel in which a large number of diamond grains are dispersed and arranged in a single layer on a surface of a planar circular substrate and fixed by brazing.
The diamond particles are brazed and fixed to the substrate with Ni brazing material, and then fine spherical glass beads are sprayed on the surface of the diamond particles and the brazing material surface by a blasting device to remove the brazing material on the surface of the diamond particles. In addition, a single-layer diamond wheel is characterized in that the surface of the brazing material is formed smoothly and smoothly.

The present invention according to claim 2 is the method according to claim 1,
The glass beads having a particle size of # 80 to 140 are used, the glass beads are jetted on both sides of the substrate, and distortion on one side due to the jetting is removed from the other side. Diamond wheel.

According to a third aspect of the present invention, in the first or second aspect,
After the glass beads are sprayed, the entire surface is vapor-deposited with a TiAlN film by ion plating.

A fourth aspect of the present invention provides the method according to any one of the first to third aspects,
It is a single-layer diamond wheel in which the cross section of the outer peripheral end surface of the substrate is smoothly curved in a convex arc shape over the entire width.

The present invention according to claim 5 provides:
The single-layer diamond wheel according to any one of claims 1 to 4 is used in a metal grinding process or a cutting process in a place where an environment that hates fire or an object that hates fire. This is a method of using a single-layer diamond wheel.

The present invention described in claim 6 provides the method according to claim 5,
This is a method of using a single-layer diamond wheel, characterized in that the place where the environment that dislikes fire is inside the power plant building.

The present invention described in claim 7 provides the method according to claim 5,
It is a method of using a single-layer diamond wheel characterized by being used for cutting oil pipes as a subject that dislikes fire.
The “single layer” of the single-layer diamond wheel in the present invention means that only one layer of diamond grains exists on the substrate.

In the single-layer diamond wheel of the present invention, after the diamond particles 2 are brazed and fixed by the Ni brazing material 3, fine spherical glass beads are sprayed onto the surface of the diamond particles 2 and the surface of the brazing material 3 by a blast device. Since the brazing material on the surface of the diamond grains 2 is removed and the surface of the brazing material 3 is formed smoothly, grinding debris is smoothly removed from the surface of the brazing material 3 during clogging and clogging. It can be a long-life diamond wheel that is difficult to generate. That is, since the surface of the brazing material 3 is smooth and smooth, grinding scraps do not adhere thereto. This is because the surface of the brazing material is formed very smoothly because the glass beads ejected by the blasting device are formed in a spherical shape.
Further, the diamond particles 2 are brazed and fixed to the substrate 1 by the Ni brazing material 3 and the melting temperature of Ni is extremely high, so that the diamond particles 2 do not fall off due to heat generation during grinding. While maintaining a good environment, the life of the diamond wheel can be significantly extended.
Further, since the brazing material on the surface of the diamond grains 2 is removed, a sharpness due to the diamond grains 2 is sharp and a wheel with good grinding efficiency can be provided.

In the above configuration, the particle size of the glass beads is set to # 80 to 140, and the glass beads are jetted onto both surfaces of the substrate 1, and distortion on one side accompanying the jetting can be removed from the other side. In this case, it is possible to provide an accurate diamond wheel without distortion in the substrate 1.
Further, by limiting the particle size of the glass beads to the above range, a diamond wheel having high smoothness and high grinding force that does not leave any distortion in the substrate 1 can be obtained. That is, if the particle size is below the lower limit of the particle size, the collision energy is small and the brazing filler metal surface is not smooth, and if the upper limit is exceeded, the impact energy is too large to leave the substrate surface distorted and cannot be removed. .

In the above configuration, the entire surface can be vapor-deposited with a TiAlN film by ion plating after the glass beads are jetted. It has been found that this deposited film extends the life by about twice as compared with the case without it. This is because the removal of grinding waste is more effectively performed by the coating. That is, it is possible to effectively prevent the brazing filler metal surface from becoming smoother and the grinding dust from adhering thereto.
Furthermore, this deposited film constitutes a heat insulating layer, making it difficult to transfer heat generated during grinding to the substrate 1 and keeping the substrate 1 at a relatively low temperature to prevent the diamond particles 2 from falling off. That is, the coating can prevent melting of the brazing material 3.

  In the above configuration, the cross section of the outer peripheral end face of the substrate 1 can be smoothly curved into a convex arc shape over the entire width. In this case, grinding around the wheel can be performed smoothly.

  In the above-described configuration, the diamond wheel can be used for metal grinding or cutting in a place where an environment where fire does not like or an object which does not like fire. In this case, the occurrence of sparks during grinding or cutting can be reduced as much as possible by setting the rotational speed of the wheel to a relatively low speed. This uses Ni brazing material as the brazing material, so that the brazing material 3 and the diamond particles 2 do not fall off during grinding, and the metal surface is smoothly ground or cut by the vapor-deposited coating 4, and the diamond particles 2 are always ground. This is because heat generation can be reduced as much as possible and generation of sparks can be suppressed.

By using this single-layer diamond wheel in a power plant building, which is an environment where fire is hateful, it is possible to suppress the generation of sparks and safely perform metal grinding or cutting.
Furthermore, when used for cutting oil piping as a subject that dislikes fire, it is possible to prevent ignition of the oil along with the cutting.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partially enlarged cross-sectional view showing the main part of the diamond wheel of the present invention, and shows the manufacturing process in order. FIG. 2 is a plan view of the wheel and a cross-sectional view taken along line BB.
This single-layer diamond wheel 6 is formed into a disk shape by pressing a metal plate, and an attachment hole 7 is provided at the center, and a circular recess 8 is provided at the center. And the flat annular part 9 is provided in the radial direction outer side via the level | step-difference part 11, and the convex-arc-shaped part 5 curved smoothly over the full width at the outer peripheral end surface of the annular part 9 is provided. The diamond particles 2 are integrally brazed and fixed to the surfaces of the convex arc-shaped portion 5 and the annular portion 9 with a Ni brazing material.

Such a single-layer diamond wheel 6 can be manufactured as follows.
First, the substrate 1 having a thickness of about 0.7 to 2 mm is pressed to form a disk shape having a planar shape and a cross-sectional shape shown in FIG. Then, a powdered or paste-like Ni-based brazing material is placed or applied uniformly on the surface of the substrate 1 thinner than the maximum height of the diamond grains 2. Next, a large number of diamond grains 2 are dispersed and spaced apart from each other by at least the maximum diameter of the diamond grains 2. This diamond grain has a FEPA (Federation of European Producers of Abrasive) standard destructive inspection method (FRIATEST) with a particle size of 40/50, a Performance Index (PI) of 200 or more, and a Toughness Index (PI). ) Use a grade of 140 or higher.

  The substrate 1 thus prepared is inserted into a high-temperature furnace, and the inside of the furnace is maintained at about 1030 ° C. to 1050 ° C., which is slightly higher than the melting temperature of 1000 ° C., which is the melting temperature of the brazing material 3. Then, the diamond particles 2 are brazed and fixed integrally with the brazing material 3 by cooling and solidifying it. At this time, the additive component in the Ni-based brazing material 3 and the carbon on the surface of the diamond grains 2 are chemically bonded, and the substrate 1 and the diamond grains 2 are firmly fixed. FIG. 1 (A) shows the state after brazing, and the surface of the brazing material 3 is formed in an uneven shape. Only a part of the diamond grains 2 is exposed from the brazing material 3. Further, scattered diamond 3a adheres on the diamond particles 2.

Therefore, in the same figure, fine spherical glass beads are sprayed together with air onto the surfaces of the brazing material 3 and the diamond grains 2 by a blasting device from the upper surface side. The air pressure at this time is about 3 to 5 kg / cm ² , and the glass beads are commercially available spherical particles having a particle size of about # 80 to 140. At this time, the ceramic nozzle of the blasting device had a tip with an inner diameter of about 4 mm. And after injecting a glass bead on the front side part of a wheel, the glass bead is similarly injected on the back surface side (the diamond particle 2 is not adhering). The reason why the back surface side is also sprayed in this way is that the substrate 1 is distorted by the first glass bead spraying onto the front surface side. In order to remove it, glass beads were sprayed from the back side under the same conditions.

  By these operations, the scattering wax 3a on the surface of the diamond particle 2 is removed cleanly as shown in FIG. 1B, and the brazing material 3 having an uneven surface is smoothly formed as shown in FIG. 1A. According to experiments, the particle size of glass beads is best # 120, which includes particle sizes # 80-140. When glass beads of # 80 or less are used, the collision energy is small and the surface of the brazing material 3 cannot be formed smoothly. Further, when the particle diameter exceeds # 140, the collision energy is too large, and the distortion of the substrate 1 becomes large, and it cannot be corrected. At this time, the thickness of the substrate 1 is 1.5 mm.

The single-layer diamond wheel 6 of the present invention can be used as it is in the state of FIG. Since the scattering wax 3a is not attached to the surface of the diamond grains 2 and the surface of the brazing material 3 is formed smoothly, the grinding powder generated during grinding is smoothly removed from the brazing material 3. That is, clogging does not occur on the brazing material 3.
In addition, although the surface of the diamond particle 2 is slightly discolored at a high temperature during brazing, there is no problem in using it as a diamond wheel. Moreover, the outer periphery of the glass beads is formed in a spherical shape as described above. Therefore, the surface of the brazing material 3 was formed very smoothly, and it did not pierce the surface of the brazing material 3 like other blast materials.

  The diamond wheel of the present invention can sufficiently be used in the state of FIG. 1 (B), but more preferably, the deposited film 4 is coated on the surface of the substrate 1 and the diamond grains 2 as shown in FIG. 1 (C). It is preferable to do. The vapor deposition coating 4 is a Ti—Al—N alloy layer, and is coated on the entire surface by PVD (physical vapor deposition) ion plating. That is, TiAl is heated in a nitrogen gas atmosphere under a reduced pressure of 1 to 27 Pa, and the evaporated atoms are partially ionized by glow discharge or high-frequency plasma and deposited on a surface to which a bias voltage is applied. is there. Then, a TiAl metal nitride is deposited on the surface of the brazing material 3 and the diamond grains 2.

As described above, this vapor deposition method is ion plating in PVD and employs an arc plasma method. This feature has a high adhesion and a relatively thick film coating, and a high surface hardness. In particular, the surface coating of TiAlN has high hardness and high heat resistance.
According to experiments, it has been found that the diamond wheel having the deposited coating 4 has a life of 1.8 times or more compared to the case without the deposited wheel.

  Next, FIG. 3 shows another embodiment of the present invention, which is different from FIG. 2A in that a slit 10 exists in FIG. This slit 10 makes heat dissipation favorable.

Next, FIG. 4 shows a single-layer diamond wheel 6 showing another embodiment of the present invention, which is for cutting pipes and steel materials. As shown in FIG. 5B, the outer peripheral edge is formed with a symmetrical arc-shaped portion 5 that is symmetric across the entire width. The diamond grains 2 are brazed and fixed only to the tip and both sides of the tip. The brazing material is a Ni brazing material similar to that shown in FIG. 1, and then the brazing material is formed smoothly by glass beads. Further, TiAlN is deposited on the surfaces by the PVD ion plating arc plasma method as described above.
Further, in this example, slits 10 are formed at equal intervals on the outer peripheral edge of the substrate 1, and diamond particles 2 are also attached to the end surfaces of the slits 10 (not shown in the figure).

As shown in FIG. 4 (B), by forming the convex arc-shaped portion 5 over the entire width of the front end surface of the substrate 1, the boundary line between the faces is eliminated on the outer periphery, and the diamond particles 2 are adhered all over the outer periphery. Steel materials and the like can be cut smoothly.
According to the experiment, the occurrence of sparks at the time of cutting the steel material according to FIGS. 2 and 4 was visually less than 1/100 compared with that using a conventional grindstone. The number of rotations at this time is 10,000 rpm. That is, with a general grindstone, sparks were violently emitted from the steel material during cutting, but with the diamond wheel of the present invention, very little sparks were generated.

Further, when the rotational speed was set to 3000 rpm, the cutting ability of the conventional grindstone was drastically reduced. However, the diamond wheel of the present invention was cut without much reduction, and at that time, no spark was generated visually. There wasn't. On the other hand, the conventional grindstone generated a considerable amount of sparks even at 3000 rpm. As a result of visual observation, a spark of several tens of times the amount of spark generated at a rotational speed of 10000 rpm in the diamond wheel of the present invention occurred at a rotational speed of 3000 rpm of a conventional grindstone.
In addition, when TiN coating was performed as the vapor-deposited film 4, the life was increased by about 30% and the grinding resistance was reduced by 5%. In addition, when TiAlN coating was used, there was an effect of extending the life by 80% or more, and the grinding resistance was reduced by about 30% or more. The grinding resistance was judged based on the magnitude of the current value supplied to the grinder motor under the same conditions.

  In addition, when SiC was used as the blasting material instead of the glass bead injection in the blasting apparatus, when GC was used, and when walnuts were used, the smoothness of the surface of the brazing material was determined for SiC and GC. In addition, the substrate surface was distorted and its correction was difficult. Moreover, in the case of walnuts, it was found that the processing time is long, which is not practically preferable.

It is a principal part cross-sectional enlarged view of the single layer diamond wheel 6 of this invention, Comprising: The manufacturing process is shown to (A)-(C). The top view and BB arrow sectional drawing of the single layer diamond wheel 6 of this invention. The top view which shows other embodiment of the single layer diamond wheel 6 of this invention. The top view which shows the other example of the single layer diamond wheel 6 of this invention, and BB cross-section expanded explanatory drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Diamond grain 3 Brazing material 3a Spattering wax 4 Deposition coating 5 Convex arc

6 single-layer diamond wheel 7 mounting hole 8 circular recess 9 annular part 10 slit 11 step part

Claims (7)

In a single-layer diamond wheel in which a large number of diamond grains are dispersed and arranged in a single layer on the surface of a planar circular substrate and brazed,
The diamond particles are brazed and fixed to the substrate with Ni brazing material, and then fine spherical glass beads are sprayed on the surface of the diamond particles and the brazing material surface by a blasting device to remove the brazing material on the surface of the diamond particles. In addition, a single-layer diamond wheel is characterized in that the surface of the brazing material is formed smoothly and smoothly. In claim 1,
The glass beads having a particle size of # 80 to 140 are used, the glass beads are jetted on both sides of the substrate, and distortion on one side due to the jetting is removed from the other side. Diamond wheel. In claim 1 or claim 2,
A single-layer diamond wheel in which the entire surface is deposited and coated with a TiAlN film by ion plating after the glass beads are sprayed. In any one of Claims 1-3,
A single-layer diamond wheel in which the cross-section of the outer peripheral end face of the substrate is smoothly curved in a convex arc shape over the entire width.   The single-layer diamond wheel according to any one of claims 1 to 4 is used in a metal grinding process or a cutting process in a place where an environment that hates fire or an object that hates fire. How to use a single layer diamond wheel. In claim 5,
A method for using a single-layer diamond wheel, characterized in that the place where the environment where fire is hated is located in the power plant building. In claim 5,
A method of using a single-layer diamond wheel characterized by being used for cutting oil pipes as a subject that dislikes fire.

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