JP2000108038A - Wheel dresser and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate uneven distribution of super abrasive grain on an outer peripheral side of a grinding wheel part and prevent the falling of super abrasive grain from a side surface of the grinding wheel part by forming a layer which does not contain super abrasive grain on the side surface and an outermost peripheral part of the grinding wheel part. SOLUTION: On the side of an outer mold 21, clearance to move diamond super grain Da is provided in a bond material Ma filled between auxiliary upper and lower punches 23b, 22b. Diamond super abrasive grain Da moved to the side of the outer mold 21 by pressurization is moved in the bond material Ma between the auxiliary upper and lower punches 23b, 22b. Even in the vicinity of the side of the outer mold 21, diamond super abrasive grain Da is dispersed in the same way as at the center part and uneven distribution of a shape that much diamond super abrasive grain Da exists is prevented. In this state, sintering is performed, metallic powder Db coated with diamond super abrasive grain Da and the bond material M are integrated and sintering is completed in a state that diamond super abrasive grain Da is evenly arranged. Subsequently, the upper and lower punches 22a, 22b, 23a, 23b and the outer mold 21 are removed and a grinding wheel part 11 in which diamond super abrasive grain Da is not exposed to both side surfaces and an outermost peripheral part is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel dresser used for dressing various grinding wheels and superabrasive wheels, and a method of manufacturing the same.

[0002]

2. Description of the Related Art When a superabrasive wheel is continuously used for cutting or grinding, the sharpness gradually decreases, and poor surface roughness and poor shape occur. To correct this shape defect, a truing operation is performed. Truing is performed by pressing the tip of a wheel dresser against a rotating superabrasive wheel to remove chips adhering to the superabrasive wheel, or by cutting off an appropriate amount of a bond material.

FIG. 4 is a front view of a wheel dresser used for the dressing operation, and FIG. 5 is an enlarged side view of a main part. The dresser is fixed to a disk-shaped base 30 and an outer peripheral portion of the base 30. And a grinding wheel portion 31.
The thickness of the grindstone portion 31 is very thin, about 1 mm, and superabrasive grains having a particle size of about 0.4 mm are dispersed in this thickness.

[0004] A grindstone portion 31 of the dresser is a die (not shown) in which a mixture of superabrasive grains such as diamond and metal powder as a binder is disposed on the base metal 30 and the outer periphery of the base metal 30.
Is formed by filling and sintering between
In order to maintain a good dressing effect, it is necessary to uniformly disperse the superabrasive grains throughout the grindstone portion.

However, in the above-mentioned manufacturing method, since the specific gravity and the particle size difference between the diamond abrasive grains to be mixed and sintered and the metal powder are large, the diamond abrasive grains are biased to one side during mixing and sintering, and the homogeneity is high. It is difficult to form a whetstone part.

As a countermeasure against this, Japanese Patent Application Laid-Open No. Hei 8-141914
In the official gazette, the super-abrasive grains are coated with metal powder in advance and granulated to have a diameter of 1.5 times or more the average diameter of the super-abrasive grains, and after filling the granules in a mold, A method for producing a dresser to be sintered is disclosed. According to this manufacturing method, it is possible to obtain a more uniform grindstone portion than when a mixture of superabrasive grains and metal powder is filled.

[Problems to be solved by the invention]

However, when manufactured by the method described in the above publication, the superabrasive grains are exposed on both side surfaces of the grindstone portion, so that there is a problem that the superabrasive grains on the side surface portions are likely to fall off. In response to this problem, the present applicant has arranged a metal sheet of the same material as the coated metal powder of the superabrasive particles on the side surface in a form of sandwiching the granulated material as a method of not exposing the superabrasive particles on both side surfaces of the grindstone portion. Developing a manufacturing method of press molding and sintering, and filed as Japanese Patent Application No. 9-85383. According to this manufacturing method, since the superabrasive grains are not exposed on both sides, the superabrasive grains during use can be almost eliminated, and the granulated material is sandwiched between the metal sheets on both sides. Since sintering is performed in the state, there is an advantage that the amount of metal powder to be coated on the superabrasive particles can be reduced.

However, according to the results of the subsequent research,
It has been found that even when manufactured by the method of the prior application, the uniform arrangement of superabrasive grains is insufficient at the inner and outer peripheral portions of the grindstone portion. The reason for this is that the thickness of the grindstone is 1
The super-abrasive grains move to the inner and outer circumferences of the grindstone part due to the relatively large diameter of the super-abrasive grains being about 0.4 mm and the pressure at the time of pressure forming. This is because the super-abrasive grains are more unevenly distributed than in the central portion.

FIGS. 3A and 3B are schematic views for explaining the state of uneven distribution of abrasive grains during the above-mentioned pressure forming. FIG. 3A shows a state in which the abrasive grains are filled, and FIG. Indicates the state of time. Between the base metal 30 and the outer die 41 and the lower punch 42, the sheet S made of the bonding material and the granulated material D obtained by coating and granulating the super-abrasive particles with the metal powder are alternately filled and pressed by the upper punch 43. Then, the metal powder coated on the superabrasive grains Da is crushed in the vertical direction, and there is no gap in the whole. Here, the superabrasive grains Da are
It moves to the base metal 30 side and the outer mold 41 side in the mold by pressurization,
The super-abrasive grains Da are more unevenly distributed on the side of the base metal 30 and the side of the outer mold 41 than in the center. The uneven distribution of the super-abrasive grains Da on the base metal 30 does not cause a problem in use of the dresser, but the uneven distribution of the super-abrasive grains Da on the outer mold 41 side is caused by the following problem. Since it is different, there is a problem that the performance becomes unstable.

Further, it has been clarified that even with the dresser manufactured by the method of the prior application, it is not possible to completely prevent the superabrasive grains from falling off from the side surface of the grinding wheel. The reason for this is that the sheet made of the bonding material sandwiching the packed layer of the granulated material from both sides has an oxide film on the surface due to sintering when the sheet itself is made, and after the pressure forming at the time of making the dresser This is because the integration of the superabrasive layer and the sheet becomes insufficient during sintering, and the sheet peels off.

An object of the present invention is to provide a dresser in which a granulated material obtained by coating and granulating superabrasive grains with a metal powder is formed by pressing and firing to form a grindstone portion. An object of the present invention is to provide a wheel dresser that eliminates uneven distribution of grains and prevents superabrasive grains from falling off from the side surface of a grinding wheel.

[0012]

SUMMARY OF THE INVENTION The present invention is a wheel dresser in which a granulated material obtained by coating and granulating superabrasive particles with metal powder is pressure-formed and fired to form a grindstone portion. A layer not containing superabrasive grains is formed on the side surface and the outermost peripheral portion.

[0013] In a wheel dresser of the type in which a granulated material obtained by coating and granulating superabrasive particles with a metal powder is formed by pressing and firing to form a grindstone portion, as described above, a base metal, an outer die and a lower punch are formed. In the meantime, a method of filling the granulated material and pressing with an upper punch is used.In this case, in order to form a layer containing no super-abrasive grains on the side surface and the outermost peripheral portion of the grindstone portion, pressurizing is performed. At the time of filling of the granulated material before molding, while filling the bonding material above and below the packed layer of the granulated material, only the bonding material is filled near the outer peripheral end face so that the granulated material is not filled. Good.

In this way, if a portion consisting only of a bonding material is provided in a portion serving as both side surfaces of the grindstone portion and a portion serving as an outer peripheral end surface portion of the grindstone portion, the superabrasive grains are coated by pressure during pressure molding. The metal powder that has been integrated with the bond material of the bond material only layer, and the superabrasive grains that have moved to the outer mold side in the mold by pressing have room to escape to the part consisting of only the bond material near the outer peripheral end face Therefore, even in the vicinity of the outer peripheral end surface, the super-abrasive grains are dispersed in the same manner as in the central part, without uneven distribution in the form of a large amount of super-abrasive grains on the outer mold side, a layer containing no super-abrasive grains on the side surface and the outermost peripheral part. The formed whetstone part is obtained.

Here, a dresser in which a layer containing no superabrasive grains is formed on the outermost peripheral portion of the grindstone portion cannot be used immediately in a dressing operation as it is. Therefore, the outermost peripheral portion is polished and removed prior to use. Thus, it is necessary to make the superabrasive grains exposed. In this polishing removal operation, the outermost peripheral portion can be polished by using a general whetstone to expose the superabrasive grains.

As the base metal and the superabrasive grains, those similar to those used in a conventional dresser can be used. Further, as the metal powder used for granulation of superabrasives, copper,
Metal powders conventionally used as metal bonds, such as tin, cobalt, and iron, can be used. Known techniques can be used to coat and granulate the superabrasives with the metal powder, for example, by suspending in a device using a circulating fluidized bed,
It can be carried out by blowing a single metal such as copper, tin or iron, an alloy powder or a mixture thereof, an acrylic resin as an organic binder, and a solvent such as alcohol into the apparatus.

In the same manner as in the prior art, the dresser is filled with a granulated material obtained by coating superabrasives with metal powder between a base metal, an outer mold and a lower punch, press-forming with an upper punch, and firing. In the present invention, when the granules are filled in the mold, first, a layer of a bonding material having the same material as the coating metal powder of the granules is formed on the lower punch to a thickness of 50 mm. Approximately 200 μm, a granulated material is filled thereon, and a layer of a bonding material is further provided thereon with a thickness of approximately 50 μm to 200 μm. At this time, only the bonding material is filled in the vicinity of the outer peripheral end face, and the granulated material is not filled.

By filling and bonding the bond material and the granulated material in this way, the superabrasive grains are uniformly dispersed in the grindstone portion without being biased in the vicinity of the outer peripheral end face, and the bond material and the superabrasive are sintered by sintering. The grain layer is integrated, the superabrasive grains are not exposed on the side surface, and a grindstone portion where the superabrasive grains are hard to fall off is formed.
Furthermore, since the granulated material is sintered in a state sandwiched between the upper and lower bond layers, the amount of metal powder to be coated on the superabrasive particles can be reduced, the coating process can be performed in a short time, and the Uniform dispersion is possible with a diameter less than 1.5 times the average particle size of the superabrasives.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view showing a process for forming a grindstone portion of a dresser according to an embodiment of the present invention. In the figure, 10 is a base metal, 21 is an outer mold, 22a is a main lower punch, 22b is an auxiliary lower punch, 23a is a main upper punch, 23
b is an auxiliary punch, and D is superabrasive grains Da and metal powder Db.
, Ma is a bonding material of the same material as the metal powder Db, and M is a paste of the bonding material. As shown in the partial enlarged view, the granulated material D has diamond superabrasive grains Da serving as a core inside, and the surroundings are coated and granulated with metal powder (copper powder in the present embodiment) Db. The outer diameter of the grain D is about 1.4 times the average diameter of the diamond superabrasive grains Da (the average grain diameter is about 570 μm in the present embodiment).

The step of forming the grindstone portion in the present embodiment is as follows.
First, as shown in FIG. 1A, a ring-shaped outer die 21, a main lower punch 22 a, and an auxiliary lower punch 22
b, the auxiliary upper punch 23b is arranged, a paste-like bonding material M is applied to the upper surface of the main lower punch 22a to a thickness of about 100 μm, and the auxiliary lower punch 22b and the auxiliary upper punch 2
The bonding material Ma is filled between 3b. Next, FIG.
As shown in above, on the bonding material M of the main lower punch 22a,
A half amount of the granulated material D, which has been granulated in consideration of the volume and concentration of the bonding material M in advance, is filled in an amount required for forming a grindstone portion. In this case, the granulated material D is stacked flat (one stack).
It is desirable to do so.

Next, as shown in FIG.
Is placed on the bonding material Ma of the intermediate layer, and the same amount of the granulated material D of the first layer as shown in FIG. The granules D are filled. Separately, a paste-like bonding material M is applied to the lower surface of the main upper punch 23a to a thickness of about 100 μm, and the main upper punch 23a is formed as a second layer as shown in FIG. It is set on the granules D, and about 3,0
The granulated material D and the bonding material M are pressure-formed at a pressure of 00 to 10,000 MPa.

By this pressing, the granulated material D is crushed and the diamond super-abrasive particles Da are
Except for the 0 side, they are arranged almost uniformly. In particular, on the outer die 21 side, the diamond superabrasive grains Da have room to move in the bonding material Ma filled between the auxiliary lower punch 22b and the auxiliary upper punch 23b. Is moved to the outer mold 21 side, the moved diamond super-abrasive grains Da cause the bonding material M between the auxiliary lower punch 22b and the auxiliary upper punch 23b.
a, the diamond superabrasive grains Da are also dispersed in the vicinity of the outer mold 21 in the same manner as in the central part, and the outer mold 2
It is prevented that diamond superabrasive grains Da are unevenly distributed on one side.

By sintering in this state, the metal powder Db coated with the diamond superabrasive grains Da and the bonding material M
And sintering is completed in a state where the diamond superabrasive grains Da are evenly arranged. After this, the upper and lower punches 22
a, 22b, 23a, 23b and the outer mold 21, the diamond super-abrasive grains D
The whetstone part 11 from which a is not exposed is formed.

Thereafter, the outermost peripheral portion of the grindstone portion 11 is ground prior to use to expose the diamond superabrasive grains Da as shown in FIG. 2F, thereby providing a grindstone portion usable for dressing. Dresser is completed.

Since the dresser obtained by the manufacturing method of this embodiment is not unevenly distributed in the form of a large amount of diamond super-abrasive grains on the outer peripheral portion of the grindstone portion, it is possible to stably maintain the dressing performance during the dressing operation. Also, since the diamond superabrasive layer is integrated with the bond material and the diamond superabrasive is not exposed on both side surfaces, it is possible to prevent the diamond superabrasive from falling off during use.

In the above-described embodiment, the granulation is performed by arranging the bonding material on both sides and the middle in the thickness direction of the base metal of the grindstone portion, and coating and granulating the super-abrasive grains between each bonding material with the metal powder. Although this is an example in which sintering is performed in a state in which the material is filled, it is also possible to arrange the bonding material only on both outer sides and sinter the granulated material as a single layer. When the filling layer of the granulated material is a single layer, the dispersibility of the superabrasive particles is slightly lower than in the case of two layers, but there is an advantage that the operation of filling the granulated material is simplified.

Test Example Using the dresser of the above embodiment (inventive product), a dresser filled with only granulated material (comparative product 1), and a dresser filled with a mixture of superabrasive grains and metal powder (comparative product 2) The dressing of the superabrasive wheel was performed. The dressing conditions are as follows.・ Machine: Toyota GOP 32 × 50 ・ Wheel peripheral speed: 45 m / sec ・ Dresser peripheral speed: 10 m / sec ・ Dresser cutting depth: 2 μm / pass × 25pass =
50μm ・ Dress lead: 0.05mm / rev, 0.1mm
/ Rev (2 times each)

FIG. 2 shows the test results. As shown in the figure, in the product of the present invention, the resistance at the time of dressing (expressed by the power consumption value) is reduced to about 60% of the comparative product 1 and about 75% of the comparative product 2. In addition, in Comparative Products 1 and 2, super-abrasive grains dropped off from the side surface at the time of dressing, but no drop was found in the products of the present invention.

[0029]

(1) A portion consisting only of a bonding material is provided in a portion to be both side surfaces of the grindstone portion and a portion to be an outer peripheral end surface portion of the grinding stone portion. By filling the granulated material coated and granulated with metal powder with superabrasives, press forming and firing, by forming a layer containing no superabrasives on both sides and the outermost periphery of the grindstone part ,
Super-abrasive grains are dispersed in the same way as in the central part even near the outer peripheral end face, forming a layer that does not contain super-abrasive grains on both side surfaces and the outermost peripheral part without uneven distribution in the form of many super-abrasive grains on the outer mold side The obtained whetstone part is obtained.

(2) The outermost peripheral portion of the grindstone portion which does not include the superabrasive grains is ground and removed to expose the superabrasive grains, so that the superabrasive grains are used near the outer peripheral end face without uneven distribution. And stable dressing performance can be obtained from the beginning of use.

(3) The super-abrasive grains are not exposed on both side faces of the grindstone portion, and the super-abrasive grains are integrated with the bonding material to prevent the super-abrasive grains from falling off from both side faces. Can be.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a process of forming a grindstone portion of a dresser according to an embodiment of the present invention.

FIG. 2 is a view showing a use test result of a dresser.

FIG. 3 is a schematic diagram illustrating a state in which uneven distribution of abrasive grains occurs during pressure molding.

FIG. 4 is a front view showing a typical shape of a wheel dresser.

FIG. 5 is an enlarged view of a main part of the dresser of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Base metal 11 Whetstone part 21 Outer die 22a Main lower punch 22b Auxiliary lower punch 23a Main upper punch 23b Auxiliary upper punch D Granulated material Da Diamond super abrasive Db Metal powder M Paste bond material Ma Bond material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) B24D 3/06 B24D 3/06 A F-term (Reference) 3C047 AA13 EE11 EE18 EE19 3C063 AA02 AB02 BB02 BB07 BB15 BB23 BC02 CC02 EE40 FF23

Claims (6)

[Claims] 1. A wheel dresser in which a granulated product obtained by coating and granulating superabrasive particles with a metal powder is formed by pressing and firing to form a grindstone portion. A wheel dresser comprising a layer containing no abrasive grains. 2. A method of manufacturing a wheel dresser in which a granulated material obtained by coating and granulating superabrasive particles with a metal powder is formed by pressure forming and firing to form a grindstone portion, wherein portions serving as both side portions of the grindstone portion are provided. A portion made of only a bonding material is provided in a portion to be an outer peripheral end surface portion of the same grindstone portion, and the granulated material is filled between the bonding materials in portions to be both side surface portions of the whetstone portion, pressure-formed, and baked. A method for manufacturing a wheel dresser. 3. The wheel dresser according to claim 2, wherein said bonding material is also arranged at an intermediate portion between both side surfaces of said grinding stone portion, and said granules are filled between said bonding materials. Manufacturing method. 4. The method for manufacturing a wheel dresser according to claim 2, wherein the bonding material is made of the same material as the metal powder. 5. The method for manufacturing a wheel dresser according to claim 2, wherein a layer thickness of the bonding material disposed on both side surfaces and an intermediate portion of the grinding wheel portion is 50 to 200 μm. 6. The method for manufacturing a wheel dresser according to claim 2, wherein the diameter of the granulated product is less than 1.5 times the particle size of the superabrasive.