JP4190377B2 - Integrated compound whetstone and method for manufacturing the same - Google Patents

Description

  The present invention relates to an integrated composite grindstone in which a plurality of grindstone layers having different grinding capacities are joined together so that a plurality of machining locations on a workpiece having different machining loads on the grindstone can be ground simultaneously.

  When grinding the first and second machining locations that are located near or coupled to each other on the same workpiece and have different machining loads on the grindstone, the grinding process is divided into two parts. Typically, as shown in FIG. 13, in a workpiece W having a cylindrical portion w1 as a first machining location and a thrust part or an end surface portion w2 as a second machining location, the machining load on the grindstone of the cylindrical portion w1 When the machining allowance t2 of the end face w2 is larger than the machining allowance t1 and the processing load on the grindstone is large, the end face w2 is ground with the grindstone G2 for the end face first, and then the cylindrical part w1 is ground with another grindstone G1. Like to do.

  It is also known that the workpiece W shown in FIG. 13 is processed by a single grinding process using a single grindstone. In this case, the grindstone is integrally provided with the first grindstone layer for grinding the cylindrical portion and the second grindstone layer for grinding the end face portion, and the type, particle size, concentration, bonding degree, etc. of the abrasive grains of the second grindstone layer are set to the first. Instead of the one grindstone layer, an integrated composite grindstone in which the grinding ability of the second grindstone layer is increased is used.

  As another single grindstone for processing by one grinding process, the first grindstone layer for cylindrical portion grinding and the second grindstone layer for end face portion grinding are formed separately, and the second grindstone layer A bonding grindstone in which the grinding ability is greater than that of the first grindstone layer and both grindstone layers are bonded to the grindstone substrate with an adhesive is also conceivable.

Vitrified bonds and metal bonds are widely used as binders for holding superabrasive grains such as cubic boron nitride (CBN) abrasive grains and dies and mondo abrasive grains. In particular, as described in Japanese Patent No. 34177739 owned by the applicant of the present application, a metal bond grindstone having a strong abrasive grain retention force and excellent grinding dust discharge is known for heavy grinding. .
Japanese Patent No. 3417739 (FIGS. 1 and 2)

    However, when the grinding process is divided into two parts, the tool cost can be made relatively small, but the processing time becomes longer, and more than that, two processing machines, that is, a grinding machine for end face processing and a cylindrical part processing Or a special grinder such as a grinder equipped with a turret type grindstone head or a twin grindstone head is necessary.

  The method of machining in a single grinding process using an integrated composite grindstone in which the type, grain size, concentration, bonding degree, etc. of the abrasive grains are changed between the two grinding wheel layers is the processing load on the grinding stone at both machining locations, for example, machining allowance In the case where the values are extremely different, it is not practically possible. In particular, since the wear of the grindstone at the end face is severe, the shape accuracy of the processed workpiece is remarkably deteriorated, and frequent truing is necessary to avoid this, resulting in an increase in tool cost and a decrease in machining efficiency.

In the method of processing with the above-mentioned laminating grindstone in a single grinding step, the first grindstone layer and the second grindstone layer are not integrally formed, so the shape accuracy of the joint between the two grindstone layers is increased due to thermal strain and stress strain. It becomes inaccurate, and projections and steps are formed on the workpiece corresponding to this joint, resulting in unstable shape accuracy, making it difficult to adopt in a situation where high-precision machining is required.
Accordingly, a main object of the present invention is to provide a grindstone capable of simultaneously grinding a plurality of machining points having different grinding capabilities required on the same workpiece and a method for manufacturing the grindstone.
Another object of the present invention is to provide a grindstone that can stably maintain the shape accuracy of the joints of the plurality of machining points, and a method for manufacturing the grindstone.

In order to solve the above-described problem, the structural feature of the invention described in claim 1 is that the first grindstone layer for grinding the first machining location of the workpiece and the second machining location of the workpiece are ground at the first machining location. A second grindstone layer to be ground at the same time, and the first grindstone layer and the second grindstone layer are different from each other according to the difference in machining load required by the first machining location and the second machining location of the workpiece. The composition is composed of a binder, and the second grindstone layer is integrally bonded to the first grindstone layer to form a composite grindstone layer, which is bonded and fixed to the grindstone substrate. .

  The structural feature of the invention according to claim 2 is that according to claim 1, wherein the binder of the first grindstone layer is an oxide such as alumina (Al), silicon (Si), boron (B), etc. This is a vitrified bond made of a substance containing as a main component, and the binder of the second grindstone layer is a metal bond of a brazing material having good wettability with abrasive grains.

  The structural feature of the invention described in claim 3 is that according to claim 2, in which the metal bond is a periodic rule containing vanadium (V), a metal of Group 4A of the periodic table containing titanium (Ti). Any one of the metals in Table 5A and the group 6A in the periodic table containing chromium (Cr), and the metals in Group 1B in the periodic table containing copper (Cu), silver (Ag), etc. This is a brazing material based on the alloy of

  The structural feature of the invention described in claim 4 is that according to any one of claims 1 to 3, wherein the abrasive grains embedded in the first and second grinding wheel layers are CBN abrasive grains, diamond abrasive grains, etc. The composite grinding wheel layer is formed as a grinding wheel segment, and a plurality of composite grinding wheel layer segments are bonded and fixed to the outer periphery of the grinding wheel substrate.

  The structural feature of the invention according to claim 5 is that a large number of abrasive grains and a binder are mixed, and the mixture is molded and fired to produce a first whetstone layer, and the first whetstone layer A second grindstone in which a bonding material containing a large number of abrasive grains in a state of being bonded to at least a part of the material is formed and arranged in a predetermined shape, and the bonding material is fired to be integrally bonded to the first grindstone layer. And a step of adhering and fixing a plurality of grindstone segments each composed of the first and second grindstone layers, which are integrally coupled to each other, to the grindstone substrate, and forming the first and second grindstone layers. This is because the bonding material of the first grindstone layer and the bonding material of the second grindstone layer are made different according to the required grinding ability.

A structural feature of the invention described in claim 6 is that, in the manufacturing method according to claim 5, alumina (Al), silicon (Si), boron (B), etc., as the binder constituting the first grindstone layer. A periodic table containing a vanadium (V) group 4A metal, using a vitrified bond made of an oxide-based material, and containing titanium (Ti) as a binder constituting the second grinding wheel layer. Any one of Group 5A metals and Group 6A metals containing chromium (Cr), Periodic Table Group 1B metals containing copper (Cu), silver (Ag), etc. This is the use of a brazing material based on the alloy.
A structural feature of the invention described in claim 7 is that in the manufacturing method according to claim 6, a large number of abrasive grains embedded in the first and second grinding wheel layers are superabrasives such as CBN abrasive grains and diamond abrasive grains. The process of producing the second grindstone layer is a large number of abrasive grains, brazing material and organic binder mixed together, dried and pulverized, and each abrasive grain is surrounded by a resin layer containing the brazing material. Manufacturing a plurality of abrasive grain pieces, molding a large number of abrasive grain pieces into a space of a predetermined shape opened in the at least part of the first grinding wheel layer, and a number of integral parts with the first grinding stone layer A process of producing a bonded body of a first grindstone layer and a second grindstone layer by firing a molded body of abrasive grain pieces in an inert gas atmosphere.

  According to invention of Claim 1 of the said structure, according to the difference of the process load which the 1st process location of a workpiece | work and a 2nd process location require, a 1st grindstone layer and a 2nd grindstone layer mutually differ from each other. As a result, it is possible to simultaneously grind multiple machining locations on the same workpiece that have significantly different machining loads on the grindstone, thereby shortening the machining time and increasing manufacturing equipment costs by carrying out separate process machining. Etc. are resolved. In addition, since the first grindstone layer and the second grindstone layer are integrally joined to form a composite grindstone layer, the shape accuracy of the joints of the two grindstone layers is maintained with high accuracy and stability, and thereby the thermal deformation of the grindstone In addition, the problem that protrusions and steps are formed at corresponding parts of the workpiece due to deformation of the joints of the two grinding wheel layers due to local concentration of the processing load is eliminated.

  According to the invention of claim 2 having the above-described configuration, since the binder of the second grindstone layer is a metal bond of a brazing material having good wettability with abrasive grains, when the brazing material is melted in the firing step, The material is welded to the abrasive grains so as to rise to the surface of the abrasive grains, and becomes thin at the connecting portions between the abrasive grains to form recesses between the abrasive grains, and these recesses constitute pores. As a result, while the second grindstone layer is a metal bond grindstone, a large number of pores are formed in the bond layer, which facilitates the discharge of grinding scraps and the distribution of the grinding fluid, while the second grindstone layer withstands high load grinding. High-precision processing can be performed. In addition, the vitrified bond, which is a binder for the first grindstone layer, is composed of a substance mainly composed of oxide such as alumina (Al), silicon (Si), boron (B), etc. A metallizing layer is formed between the grains and these oxides, and this metallizing layer is fused and firmly bonded to the brazing material of the second abrasive grain layer. As a result, the second grindstone layer becomes the first grindstone layer. Firmly and integrally. As a result, the shape accuracy of the joints of both grinding stone layers is maintained with high accuracy, and the processing accuracy of the corresponding part of the workpiece grinding surface is also maintained with high accuracy. As a result, the truing interval is shortened more than necessary for shape correction. There is no need to do this, and problems such as a decrease in the wheel life and an increase in tool cost are eliminated.

  According to invention of Claim 3 of the said structure, the composition of the said metal bond is a periodic table group 4A metal containing titanium (Ti), a periodic table group 5A metal containing vanadium (V), and Basically, it is made of an alloy of any one of the metals of Group 6A of the periodic table containing chromium (Cr) and the metals of Group 1B of the periodic table containing copper (Cu), silver (Ag) and the like. Since it was set as the composition, at the time of baking of the 2nd whetstone layer, a metalizing layer is formed between each abrasive grain surface and the above-mentioned alloy, and this metalizing layer is firmly bonded with the abrasive grains of the 2nd whetstone layer. On the other hand, the first grinding wheel layer is also firmly bonded to the binding material, whereby the effect of the invention according to claim 2 can be more remarkably exhibited.

  According to the invention of claim 4 having the above-described configuration, the abrasive grains embedded in the first and second grinding stone layers are superabrasive grains such as CBN abrasive grains and diamond abrasive grains, and the composite grinding stone layer is formed as a grinding stone segment. Since a plurality of composite grindstone layers are bonded and fixed to the outer periphery of the grindstone substrate, in addition to the effects of the above-described inventions, a composite grinding grindstone with a high accuracy of shape accuracy is ensured by a relatively easy manufacturing process. Obtainable.

  According to invention of Claim 5 of the said structure, a 2nd grindstone layer shape | molds and arrange | positions the binding material containing many abrasive grains in the predetermined shape in the state adhere | attached on at least one part of the 1st grindstone layer. In addition, the bonding material is fired so as to be integrally bonded to the first grindstone layer, and the bonding material of the first grindstone layer and the second grindstone layer according to the grinding ability required for the first and second grindstone layers. Thus, the same effect as that of the first aspect of the invention can be obtained. Moreover, since the firing step of the first grindstone layer and the firing step of the second grindstone layer are separated, the first and second grindstone layers are formed by binders having greatly different firing conditions such as firing temperature, time, and atmosphere. It is possible to combine and combine a grindstone layer having a different composition and a different bonding material.

According to invention of Claim 6 of the said structure, the vitrified bond which consists of a substance which has oxides, such as an alumina (Al), silicon (Si), and boron (B), as a main component as a binder which comprises a 1st grindstone layer. As a binder constituting the second grinding wheel layer, a periodic table group 4A metal containing titanium (Ti), a periodic table group 5A metal containing vanadium (V), and chromium (Cr). A brazing material based on an alloy of any one of the metals in Group 6A of the periodic table and a metal in Group 1B of the periodic table including copper (Cu), silver (Ag), etc. Since it is used, the same effect as that of the invention of claim 3 can be obtained.
According to the invention of claim 7 having the above-described configuration, a large number of CBN abrasive grains, superabrasive grains such as dies and mondo abrasive grains, a brazing material, and an organic binder are mixed, dried, and pulverized to surround each abrasive grain. In this method, a large number of pieces of abrasive grains in which the brazing material is held by the resin layer are formed, and the pieces of abrasive grains are molded into a space having a predetermined shape opened to at least a part of the first grindstone layer and fired. Since the 2nd whetstone layer was formed, the brazing material which connects between each abrasive grain is disperse | distributed uniformly, and the bond strength of an abrasive grain can be made uniform over the whole 2nd whetstone layer.

(Example 1)
Embodiments of an integrated composite grindstone and a method for manufacturing the same according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a cross-sectional view of an integrated composite grindstone 10 according to the present invention. The composite grindstone 10 was bonded and fixed on the grindstone substrate 11 formed of any material such as steel, aluminum, titanium, etc., an underlayer 12 formed on the outer periphery of the substrate 11, and the underlayer 12. It is comprised from the integral type composite grindstone layer 13. The composite grinding wheel layer 13 includes a cylindrical grinding wheel layer 14 as a first grinding wheel layer for grinding a cylindrical portion w1 as a first grinding location of a workpiece (workpiece) W, and an end surface as a second grinding location of the workpiece W. It comprises an end face grinding wheel layer 15 as a second grinding wheel layer for grinding the portion w2. The cylindrical grinding wheel layer 14 and the end surface grinding wheel layer 15 are basically configured by changing the type of the binder. Specifically, the cylindrical grinding wheel layer 14 is formed by bonding superabrasive grains such as diamond or cubic boron nitride (CBN) with vitrified bonds, and the end grinding grinding wheel layer 15 is made of the superabrasive grains made of metal. It is composed by bonding with a bond. In the present embodiment, the cylindrical grinding wheel layer 14 and the end surface grinding wheel layer 15 both use CBN abrasive grains as superabrasive grains.

  The cylindrical grinding wheel layer 14 as the first grinding wheel layer is formed by dispersing and holding a large number of CBN abrasive grains by vitrified bonds. The vitrified bonds are oxidized of alumina (Al), silicon (Si), boron (B) or the like. It consists of a substance whose main component is an object. The end surface grinding wheel layer 15 as the second grinding wheel layer is formed by dispersing and holding a large number of CBN abrasive grains by metal bonds. As shown in FIG. 7, in this metal bond grindstone layer, a large number of CBN abrasive grains Pg are brazed by a brazing material 15a, and as will be described later, a metalizing layer having good wettability with respect to a molten brazing material 15a is formed. Since it is formed on the surface of the CBN abrasive grains Pg, the molten brazing material 15a adheres to the periphery of the CBN abrasive grains Pg and the underlying layer with a strong holding force, and gaps between the metal grains gather between the abrasive grains Pg. Thus, a large number of pores 15b are formed. The foundation layer 12 is configured to have intermediate characteristics between the characteristics of the vitrified bond layer of the cylindrical grinding wheel layer 14 and the characteristics of the grinding wheel substrate 11. That is, the foundation layer 12 is excellent in affinity with the grindstone substrate 11 and the cylindrical grinding wheel layer 14, and has an intermediate to firmly fix the cylindrical grinding wheel layer 14 to the grindstone substrate 11.

  As shown in FIG. 2, the composite grindstone layer 13 is configured as a segment grindstone divided in the circumferential direction of the grindstone substrate 11, and is sequentially bonded and fixed onto the base layer 12 with an appropriate adhesive, so that the entire outer periphery of the grindstone substrate 11 is formed. A continuous grinding surface is formed.

  When grinding the workpiece | work W using the grindstone 10 comprised in this way, the grindstone 11 and the workpiece | work W are relatively plunged and fed. In this case, the second grindstone layer 15 first comes into contact with the end surface portion w2 of the workpiece W, and this end surface portion w2 is ground. The second grindstone layer 15 strongly grinds the end face portion having a large machining allowance t2 by a strong abrasive grain holding action by the metal bond. In the second grindstone layer 15 composed of this metal bond, as shown in FIG. 7, the brazing material 15a for bonding the CBN abrasive grains Pg is strong against the periphery of the CBN abrasive grains Pg and the base layer 12. Adhering with holding force, gaps between metal grains are gathered between each of the abrasive grains Pg to form a large number of pores 15b, so that the discharge of grinding dust and the supply of the grinding fluid are sufficiently ensured and clogging occurs. It has a structure that is difficult to do. Thereby, grinding of end face part w2 is performed efficiently.

  In the final stage of the plunge grinding process, in a state where the second grindstone layer 15 is grinding the end surface portion w2 of the workpiece W, the first grindstone layer 14 comes into contact with the cylindrical portion w1 of the workpiece W, and this cylindrical portion w1 is ground. To do. The first grindstone layer 14 is composed of vitrified bond, and the abrasive grain holding power of the binder itself is relatively strong but brittle. Therefore, the first grindstone layer 14 is excellent in discharging grinding dust and crushed abrasive grains. The finishing surface accuracy of the cylindrical portion w1 ground by the abrasive layer 14 can be improved. That is, according to the integrated composite grindstone 10 according to the present embodiment, a plurality of machining points w1 and w2 having different machining loads on one workpiece W are formed at the second grinding wheel layer 15 at a machining point w2 having a large machining load. A processing point w1 that can be ground efficiently and has a small processing load and requires high surface accuracy is characterized by being capable of being ground with high precision by the first grindstone layer.

  In the grindstone 10 according to this embodiment, the first and second grindstone layers 14 and 15 are configured as CBN grindstones having substantially the same particle size and concentration, but both the grindstone layers 14 and 15 are vitrified by the first grindstone layer 14. It is configured as a bond grindstone, and is different in that the second grindstone layer 15 is configured as a metal bond grindstone. In other words, in order to grind the processing points w1 and w2 having different processing loads on the grindstone, by combining the processing points w1 and w2 with a combination of vitrified bond and metal bond as a binding material, The first and second grinding wheel layers 14 and 15 are different in grinding ability with respect to the required processing load.

  In the grindstone 10 according to this embodiment, the first grindstone layer 14 constituted by vitrified bond and the second grindstone layer 15 constituted by metal bond are integrally coupled. Since both the whetstone layers 14 and 15 are integrally coupled, the shape of the joint portion between the both whetstone layers 14 and 15 is always stable. In the grindstone according to the present embodiment, the conventional laminating grindstone has a problem, that is, thermal deformation of the grindstone substrate caused by a configuration in which separate grindstone layers for different processing locations are bonded and fixed to the grindstone substrate with an adhesive. There is almost no deformation of the shape of the joint part of both grinding stone layers accompanying centrifugal expansion deformation. Thereby, in the composite grindstone layer 13 of the present embodiment, the joint between the straight line portion and the arc portion becomes accurate, and the workpiece W to be machined has a circumferential protrusion or step at the joint between the straight portion and the arc portion. There are no defects such as formation.

  Next, the manufacturing method of the integrated composite grindstone according to the present embodiment will be described with reference to FIG. This manufacturing method generally includes a manufacturing process PC1 of the first grindstone layer 14 formed by vitrified bond, and a manufacturing process of forming the second grindstone layer 15 by metal bond in a state of being bonded to the first grindstone layer 14. This is composed of a manufacturing process PC3 for manufacturing the integrated composite grinding wheel 10 by bonding the PC2 and the composite grinding stone layer 13 as a combined body of the first and second grinding stone layers 14 and 15 to the grinding wheel substrate 11. In addition, although the 1st whetstone layer 14 and the 2nd whetstone layer 15 can all be manufactured also as an integrally molded body which surrounds the outer periphery of the grindstone board | substrate 11, in this Example, the 1st whetstone layer 14 is made into a segment. A plurality of them are manufactured, and the second grindstone layer 15 is integrally formed on each segment 14.

  In the manufacturing process PC1 of the first grindstone layer 14, CBN abrasive grains and clay-like vitrified bonds are mixed and molded into a grindstone mold 20 as shown in FIG. The vitrified bond is composed of a substance whose main component is an oxide such as alumina (Al), silicon (Si), or boron (B). The grindstone molding die 20 includes a lower die 21, a mold 22 and an upper die 23 as main components, and the second grindstone layer simulation body 24 is held in engagement with a dovetail groove so that it can be inserted and removed in the vertical direction. The second grindstone layer simulation body 24 defines a forming space 20 a of the first grindstone layer 14 together with the lower mold 21, the mold 22 and the upper mold 23. The molding space 20a is formed as an arc surface in a direction perpendicular to the paper surface corresponding to the arc curvature of each grindstone segment 14, and a lower surface portion 23a defining the upper surface of the molding space 20a of the upper mold 23 is also perpendicular to the paper surface. It is formed in an arc shape. The upper mold 23 is formed with a dovetail groove 25 into which an arc surface forming member 26 of the second grindstone layer 15 described later is inserted.

An appropriate amount of a mixture of CBN abrasive grains and clay-like vitrified bond is filled in the grinding wheel molding space 20a of the grinding stone molding die 20, and the upper die 23 is pushed into the mold 22 to have a predetermined shape corresponding to the first grinding wheel layer. Mold. Subsequently, the molded body of the mixture of the abrasive grains and the vitrified bond is baked and solidified in an atmosphere of 700 ° C. to 1000 ° C. in the baking step while being die-cut or molded. Thereby, the 1st whetstone layer 14 of a vitrified structure is formed.

  In the manufacturing process PC2 of the second grindstone layer 15, an organic binder is added to a metal bond and kneaded, and further CBN abrasive grains are added to make a paste-like mixture. Here, the metal bond is a periodic table group 4A metal containing titanium (Ti), a periodic table group 5A metal containing vanadium (V), and a 6A group periodic table containing chromium (Cr). It is constituted by a brazing material made of an alloy of a metal of any one of the above metals and at least one metal of Group 1B of the periodic table containing copper (Cu), silver (Ag), etc. Is done.

  Next, this mixture is heated to about 100 ° C. and dried to scatter the organic binder contained in the mixture. After drying, the solidified mixture is pulverized and sieved to obtain abrasive pieces. As shown in FIG. 6, in this abrasive grain piece, a resin layer 32 containing metal powder 31 is fixed to the outer surface of each CBN abrasive grain Pg on the outer surface of each CBN abrasive grain Pg. A large number of abrasive grain pieces thus obtained are molded by molding. In this case, the second grindstone layer simulation body 24 is extracted from the mold 22, thereby forming the mold 22 in a state where the second grindstone layer simulation body 24 is extracted on one end surface of the first grindstone layer 14. Two grinding wheel layer forming spaces 20b are formed as shown in FIG.

  The second grindstone layer forming space 20b is filled with a large number of abrasive grains (see FIG. 6), the arc forming member 26 is engaged with the dovetail groove of the upper mold 23 from the left end surface side in FIG. The second grindstone layer 15 is molded and solidified by being pushed into the frame 22, and the arc-shaped lower surface of the arc-forming member 26 is pressed against the upper surfaces of a large number of abrasive grains filled in the second grindstone layer-forming space 20b. A circular arc-straight line connection surface that smoothly connects the circular arc surface of the two grinding wheel layers 15 to the linear portion of the first grinding wheel layer 14 is formed. After this mold-molding, the assembly of the lower mold 21 and the mold 22 is placed in a firing furnace while the second grindstone layer 15 mold-molded integrally with the first grindstone layer 14 is held in the grindstone mold 20. Then, it is fired at a firing temperature of 840 ° C. to 940 ° C. in an inert gas such as argon gas or in a vacuum atmosphere.

In this firing process, a metalizing layer made of titanium boron (TiB) or the like is formed between boron (B) and titanium (Ti) on the surface of the CBN abrasive grains forming the second grindstone layer 15. Since these metallizing layers and metals of Group 1B of the periodic table containing copper (Cu) and silver (Ag) are easily fused, the wettability between the CBN abrasive grains and the brazing material is improved through the metallizing layer. . Metallizing layer formed on the surface of the CBN abrasive particles Pg, since the good wettability against the brazing material in a molten state, as shown in FIG. 7, brazing material 15a melted adheres around the CBN abrasive Pg The brazing material 15a between the adjacent CBN abrasive grains Pg has a shape in which the portion in contact with the CBN abrasive grains Pg is high and the intermediate portion is low, and a large recess, that is, a pore 15b is formed between the adjacent CBN abrasive grains Pg. . If this is cooled, the brazing material 15a swells and adheres around the CBN abrasive grains Pg, and a second grindstone layer 15 is formed in which pores 15b are formed between adjacent CBN abrasive grains Pg.

  In addition, a metalizing layer is formed on the oxide which is the main component in the vitrified composition on the joint surface with the first grindstone layer 14, and copper (Cu) and silver (Ag) in the metalizing layer and the metal bond are formed. Therefore, the CBN abrasive grains of the first grindstone layer 14 and the metal bond composition of the second grindstone layer 15 are the same as those of the metallizing layer and the group 1B of the periodic table. The fusion with the metal improves the wettability between the two, and the bonding strength between the two becomes strong. As a result, a composite superabrasive grindstone 13 in which a metal bond grindstone (second grindstone layer) 15 is directly and firmly bonded to the vitrified grindstone (first grindstone layer) 14 by metal fusion is obtained as a grindstone segment.

  After firing is performed in this manner, the composite grindstone segment 13 is removed from the grindstone mold 20, and shape shaping for substrate attachment such as the contact state of the adhesive surface with the grindstone substrate 11 is performed. Thereafter, the composite grindstone segment 13 is appropriately bonded to the outer periphery of the grindstone substrate 11 with an adhesive, and correction of runout or the like of each composite grindstone segment 13 in an adhesively fixed state to the grindstone substrate 11, that is, forming a final finished shape as a grindstone. Is performed to complete the integrated composite grindstone 10.

(Other variations)
In the above-described embodiment, the second grindstone layer 15 is a multi-layer, but FIGS. 8 and 9 show the main part of the manufacturing method in the first and second variations in which the second grindstone layer 15 is a single layer. . In these first and second modifications, an arcuate end surface 14a is formed on the first grindstone layer 14, and this end surface 14a is slightly larger than the average particle size of the CBN abrasive grains Pg as shown in FIG. An arcuate recess 29 having a depth H1 is formed.

  Then, in the manufacturing method of the first modification, as shown in FIG. 8 showing the main part of the manufacturing process, a paste-like mixture in which a metal bond and an organic binder are mixed without including CBN abrasive grains is prepared. As shown in FIG. 11, the mixture is applied to the arc-shaped recess 29 to form the coating layer 30. In this case, the thickness of the coating layer 30 is about 60% of the average particle diameter of the CBN abrasive grains Pg. Next, as shown in FIG. 12, CBN abrasive grains Pg are embedded in the paste-like mixture coating layer 30 along the generatrix of the arc-shaped recess 29. Subsequently, the grindstone layer segment in which the CBN abrasive grains Pg are embedded in the arc-shaped recess 29 on the end face of the first grindstone layer 14 is fired in an inert gas atmosphere in a firing furnace in the firing step of the manufacturing process PC2. Thereby, the grindstone layer combination 13 in which the second grindstone layer 15 made of one metal bond abrasive grain layer is integrally formed on the arcuate end surface 14a of the first grindstone layer 14 made of the vitrified abrasive grain layer is produced. The grindstone layer combination 13 is bonded to the grindstone substrate 11 through the manufacturing process PC3 described above, and the integrated composite grindstone 10 is manufactured.

  In the manufacturing method of the second modified example, as shown in FIG. 9 showing the main part of the manufacturing process, a paste-like mixture is prepared by mixing the metal bond and the organic binder including the CBN abrasive grains Pg. Then, the paste-like mixture containing the CBN abrasive grains Pg is applied along the generatrix of the arcuate recess 29 shown in FIG. 10, and the CBN abrasive grains Pg are arranged in the arcuate recess 29 as shown in FIG. That is, in the manufacturing method of the second modification, the process of FIG. 11 is omitted. Subsequently, the grindstone layer segment in which the CBN abrasive grains Pg are applied and arranged in the arcuate recess 29 of the arcuate end surface 14a of the first grindstone layer 14 is placed in an inert gas atmosphere in the firing furnace in the firing process of the manufacturing process PC2. By firing, a grindstone layer combination 13 is formed in which the second grindstone layer 15 made of a single metal bond abrasive grain layer is integrally formed on the arcuate end surface of the first grindstone layer 14 made of a vitrified abrasive grain layer. The grindstone layer combination 13 is bonded to the grindstone substrate 11 through the manufacturing process PC3 described above, and the integrated composite grindstone 10 is manufactured.

  In the above-described embodiment and its modification, the grindstone 10 includes two grindstone layers 14 and 15 having different binder compositions. However, the grindstone 10 has different binder compositions adjacent in the axial direction. Three or more grindstone layers may be provided. In this case, as an example in the case of three whetstone layers, it is comprised as a compound whetstone layer which integrally combined three whetstone layers, an electrodeposition whetstone layer, a metal bond whetstone layer, and a vitrified bond whetstone layer.

  In the said Example, although the example which uses CBN abrasive grain Pg as an abrasive grain was described, it replaced with CBN abrasive grain Pg and can use a diamond abrasive grain. Here, if the CBN abrasive grains Pg in FIG. 7 are described as the diamond abrasive grains Pg, in the second grindstone layer 15 that holds the diamond abrasive grains Pg by metal bonds, the metal bonds may be free of argon gas or the like in the firing step. When melt bonded at a firing temperature of 840 to 940 ° C. in an active gas or vacuum atmosphere, a metallizing layer made of titanium carbide (TiC) or the like is formed between the diamond abrasive grains Pg and titanium (Ti). It is formed. These metallizing layers are easily fused with the metals of Group 1B of the periodic table including copper (Cu) and silver (Ag), and the wettability between the diamond abrasive grains Pg and the brazing material 15a through the metallizing layer. Get better. Since the metalizing layer formed on the surface of the diamond abrasive grains Pg has good wettability to the molten brazing material 15a, the molten brazing material 15a adheres to the periphery of the diamond abrasive grains Pg and rises, and the adjacent diamond The brazing material 15a between the abrasive grains Pg has a shape in which the portion in contact with the diamond abrasive grains Pg is high and the intermediate portion is low, and a large dent is formed as a pore 15b between the adjacent diamond abrasive grains Pg. Thereby, the metal bond diamond abrasive grain layer with strong abrasive grain holding power and excellent dischargeability of grinding dust is formed.

  In the above-described embodiment, as an example of a grindstone having a grindstone layer corresponding to a processing load as a different required characteristic, a composite grindstone in which a cylindrical grindstone layer and an end face grindstone layer are integrally formed is illustrated. Is not limited. For example, in the case of a composite work in which the materials of two adjacent cylindrical portions on the same axis are different, the grinding stone layers for grinding the two cylindrical portions are changed by changing the binding material constituting the respective grinding stone layers. A grinding ability may be provided.

  Moreover, in order to give the grinding capability corresponding to a different processing load to the some grindstone layer on a grindstone, although the combination of the vitrified bond grindstone and the metal bond grindstone was illustrated, it is good also as a grindstone which combined another binder. For example, a combination of a vitrified bond grindstone and a resinoid bond grindstone or a combination of a metal bond grindstone and a resinoid bond grindstone can be adopted. Can be used in combination.

  In the above-described embodiment, the second grinding wheel layer 15 for end face grinding is continuously formed on the entire outer periphery of the grinding wheel substrate 11, but is not formed on the entire surface but is scattered or intermittently formed. Also good.

The partial cross section top view which shows an example of the Example of the integral type composite grindstone by this invention, and a workpiece | work to be ground. The perspective view which shows the attachment structure of the grindstone segment adhere | attached and fixed to a grindstone board | substrate. The manufacturing process block diagram which shows the manufacturing process of the integrated composite grindstone by this invention. Sectional drawing of the grindstone shaping | molding die which shape-molded the 1st grindstone layer for cylindrical part grinding. Sectional drawing of the grindstone shaping | molding die which carried out the molding of the 2nd grindstone layer for end surface part grinding | polishing in the edge part of the 1st grindstone layer. Sectional drawing of the CBN abrasive grain coat | covered with the resin layer which includes a metal bond in an outer periphery. Sectional drawing for demonstrating the structure | tissue of the CBN metal bond grindstone which forms a pore between abrasive grains. The principal part block diagram of the manufacturing process of the 1st modification which changed a part of manufacturing process shown in FIG. The principal part block diagram of the manufacturing process of the 2nd modification which changed a part of manufacturing process shown in FIG. The partial expanded sectional view of the 2nd grindstone layer in the 1st modification shown in FIG. The partial expanded sectional view of the 2nd grindstone layer in another manufacturing process in the 1st modification shown in FIG. The partial expanded sectional view of the 2nd grindstone layer in another manufacturing process in the 1st modification shown in FIG. Explanatory drawing which shows the conventional method of grinding a cylindrical part and an end surface part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Integrated compound whetstone, 11 ... Whetstone substrate, 12 ... Underlayer, 13 ... Whetstone layer, 14 ... Cylindrical whetstone layer, 15 ... End face whetstone layer, 15a ... Raw material, 15b ... pores, W ... workpiece (workpiece), w1 ... cylindrical machining part, w2 ... end face machining part, PC1 ... first grinding wheel layer manufacturing process, PC2 ... Second whetstone layer manufacturing process, PC3... Integrated composite whetstone manufacturing process, 20... Whetstone forming mold, 21... Lower mold, 22. -2nd whetstone layer simulation body, 26 ... arc surface formation member, Pg ... CBN abrasive grain, 29 ... arc-shaped dent, 30 ... coating layer, 31 ... metal bond powder, 32 ... Resin layer.

Claims (7)

A first grindstone layer for grinding the first machining location of the workpiece and a second grinding wheel layer for grinding the second machining location of the workpiece simultaneously with the machining of the first machining location. The grindstone layer is composed of different binders according to the difference in machining load required by the first machining location and the second machining location of the workpiece, and the grinding wheel layer is different from the first grinding stone layer. An integrated composite grindstone, wherein the second grindstone layer is integrally bonded to form a composite grindstone layer, and the composite grindstone layer is bonded and fixed to a grindstone substrate .
2. The integrated composite grindstone according to claim 1, wherein the binder of the first grindstone layer is a vitrified bond made of a substance whose main component is an oxide such as alumina (Al), silicon (Si), or boron (B). And the bonding material of the second grindstone layer is a metal bond of a brazing material having good wettability with abrasive grains. 3. The integrated composite grindstone according to claim 2, wherein the metal bond includes a metal of Group 4A of the periodic table containing titanium (Ti), a metal of Group 5A of the periodic table containing vanadium (V), and chromium ( It is basically composed of an alloy of any one of the metals in Group 6A of the periodic table containing Cr) and the metals in Group 1B of the periodic table containing copper (Cu), silver (Ag), etc. An integrated composite grindstone characterized by that. 5. The integrated composite grindstone according to claim 1, wherein the abrasive grains embedded in the first and second grindstone layers are superabrasive grains such as CBN abrasive grains and diamond abrasive grains, and the composite grindstone layer is formed. Is formed as a grindstone segment, and a plurality of the composite grindstone layers are bonded and fixed to the outer periphery of the grindstone substrate. A process for producing a first grindstone layer by mixing a large number of abrasive grains and a binder, mold-molding and firing the mixture, and a plurality of abrasive grains adhered to at least a part of the first grindstone layer. And forming a second whetstone layer integrally bonded to the first whetstone layer by firing the bonding material into a predetermined shape and arranging the same, and each of them is integrally bonded to each other. A plurality of grindstone segments composed of the first and second grindstone layers are bonded and fixed to a grindstone substrate, and the first grindstone layer is bonded according to the grinding ability required for the first and second grindstone layers. A method for producing an integrated composite grindstone, characterized in that the bonding material of the material and the second grindstone layer is different. 6. The manufacturing method according to claim 5, wherein a vitrified bond made of a substance mainly composed of an oxide such as alumina (Al), silicon (Si), boron (B), or the like is used as a binder constituting the first grindstone layer. And a periodic table group 4A metal containing titanium (Ti), a periodic table group 5A metal containing vanadium (V), and chromium (Cr) as a binder constituting the second grindstone layer. A brazing material based on an alloy of any one of the metals in Group 6A of the periodic table and a metal in Group 1B of the periodic table including copper (Cu), silver (Ag), etc. A method for producing an integrated composite grindstone characterized by being used. The manufacturing method according to claim 6, wherein a plurality of abrasive grains embedded in the first and second grinding wheel layers are superabrasive grains such as CBN abrasive grains and diamond abrasive grains, and the second grinding wheel layer is manufactured. A step of mixing a large number of abrasive grains, the brazing material and an organic binder, drying and then pulverizing to produce a large number of abrasive grains each surrounded by a resin layer containing the brazing material; A step of mold-molding the plurality of abrasive grain pieces into a space having a predetermined shape opened to the at least part of the first grinding wheel layer, and a molded body of a large number of abrasive grain pieces integrated with the first grinding wheel layer. And a step of producing a combined body of the first grindstone layer and the second grindstone layer by firing in an inert gas atmosphere.

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