JP5468110B2 - Manufacturing method of grindstone with recess - Google Patents

Description

  The present invention relates to a method for manufacturing a grindstone with a recess in which an inclined groove or a hole-shaped recess is formed on a segment type grindstone chip affixed to a core.

  An abrasive layer containing superabrasive grains such as diamond or cubic boron nitride is formed on the outer peripheral surface of a disk-shaped core that is driven to rotate about the axis, and a predetermined width and depth are formed on the outer peripheral surface of the abrasive layer. Patent Document 1 discloses a grooved grindstone in which an inclined groove having a thickness is engraved with an inclination of about 25 to 45 degrees with respect to the axis of the core. According to such a grooved grindstone, the grinding liquid can be effectively introduced to the grinding point along the inclined groove, and the removal amount by grinding is about 1.5 times that of the grindstone without the inclined groove. It is possible to increase the grinding efficiency.

  In addition, the grinding fluid supplied to the grinding point generates dynamic pressure between the workpiece and the grinding wheel, and this dynamic pressure prevents the workpiece from being displaced relative to the grinding wheel to prevent deterioration in machining accuracy and efficiency. In order to achieve this, it is considered to provide a groove on the grinding surface of the grindstone to release the dynamic pressure. It is also considered that a plurality of holes are provided in the grinding surface instead of such grooves to release the dynamic pressure.

JP 2000-354969 (paragraphs [0007], [0026], FIG. 1)

  In order to provide grooves on the grinding surface of the grindstone, if superabrasive grains and a binder are baked after press molding and then the inclined grooves are engraved on the grinding surface of the grindstone chip that has been affixed to the core, the superabrasive grains are strengthened. Since an inclined groove or a hole-like recess is machined in an abrasive layer held by a binder, machining is difficult, for example, due to excessive wear of a grooving grindstone. In addition, when the inclined groove or hole-shaped recess is engraved by machining in the abrasive grain layer of the grindstone chip after firing, the superabrasive grains exposed on the grinding surface at the side wall portion of the inclined groove or the inner wall portion of the hole-shaped recess The holding force is reduced by machining, and the superabrasive grains easily fall off.

  An object of the present invention is to easily form an inclined groove or a hole-shaped concave portion inclined with respect to the circumferential direction of the grindstone at a low cost by machining or pressing in the abrasive grain layer of the grindstone chip before firing.

In order to solve the above-described problem, the structural feature of the invention according to claim 1 is that a superabrasive is attached to a core mounted on a grindstone shaft that is rotatably supported around a rotation axis on a grindstone base of a grinding machine. A workpiece in which a plurality of grindstone chips made of an abrasive layer containing grains and an underlayer are affixed, and a grinding surface formed on the abrasive layer is rotatably supported on a workpiece support device of the grinding machine. In the method of manufacturing a grindstone that abuts and grinds at a grinding point, a concave surface is formed on the surface of the grinding surface molding portion of a press mold for molding the grinding wheel tip, and a plurality of inclined groove forming plates protrude from the surface of the grinding surface molding portion. A plurality of inclined grooves formed of carbon or resin are attached to a plurality of mounting grooves that are fitted to each other in a direction that becomes the circumferential direction of the grindstone when the grindstone chip to be molded is affixed to the core. inclination for detachably erected to each inclination for The groove forming plate standing step, and the press mold is filled with a powder for an abrasive layer in which a plurality of superabrasive grains and a binder are mixed, and the powder for the base layer is mixed with the base particles and the binder The powder filling step of filling the powder for the abrasive layer and the powder for the abrasive layer and the powder for the ground layer are not separated by the inclined groove forming plate. A press molding step for integrally press-molding, and an abrasive layer and a base layer are integrally formed by the press molding, and the plurality of inclined groove molding plates are fired in a state of penetrating at least the abrasive layer A mold release step of releasing the pre-whetstone chip from the press mold together with the plurality of inclined groove forming plates, and the inclined groove forming plate is burned away during the firing of the pre-firing grindstone chips with respect to the circumferential direction of the grindstone. after multiple inclined groove-like recesses which are inclined Te is provided in the abrasive grain layer baked A firing step of forming a stone chip and by providing the.

According to the first aspect of the present invention, a plurality of inclined groove-like recesses are formed in the grindstone chip before firing, and then fired. Therefore, as in the case of inclined groove-shaped recesses are engraved by machining the abrasive layer of the grinding chips after firing, with the inner side wall portion of the inclined groove-like recess holds the superabrasive grains exposed on the grinding surface A highly durable grindstone that firmly holds superabrasive grains can be easily produced at low cost without the force being reduced by machining.
Further, the ground layer is superimposed on the abrasive layer filled in the grinding surface forming portion and integrally press-molded to form a pre-firing grindstone chip provided with inclined grooves inclined with respect to the circumferential direction of the grindstone. Therefore, the process only for providing the inclined groove can be omitted, and the side wall of the inclined groove is ground as in the case where the inclined groove is engraved by machining in the abrasive layer of the grindstone chip after firing. The holding power of the superabrasive grains exposed on the surface is not reduced by machining, and a highly durable grindstone that firmly holds the superabrasive grains can be easily produced at low cost.
Further, carbon is provided in a plurality of mounting grooves that are recessed in the surface of the grinding surface molding portion of the press mold for molding the grindstone chip, and in which a plurality of inclined groove molding plates are respectively fitted so as to protrude from the surface of the grinding surface molding portion. Since a plurality of inclined groove forming plates made of resin or resin are detachably installed so as to be inclined with respect to the direction of the grindstone circumferential direction when the grindstone chip to be molded is affixed to the core, the grindstone before firing When releasing the chip, the plurality of inclined groove forming plates can be easily removed from the ground surface forming portion together with the pre-firing grindstone chip. And since the multiple inclined groove forming plates made of carbon or resin can be burned down by the high temperature at the time of firing the grindstone chip, the step of removing the inclined groove forming plate from the grindstone chip before firing is omitted. A plurality of inclined groove-like recesses can be formed at a time, and the production efficiency can be improved. In addition, when the inclined groove forming plate is burned off, the end of the inclined groove- shaped recess of the grindstone tip is not cut or deformed, so that the quality can be improved.

The whole figure of the grindstone which consists of the segment type grindstone tip which shows the 1st embodiment of the present invention. The figure which shows the state which grinds a workpiece with the grinder equipped with the grindstone with an inclined groove. The figure which shows a grindstone chip. The figure which shows the state which engraved the some inclined groove | channel on the grinding surface of the grindstone so that at least 1 inclined groove might always pass a grinding point. The figure which shows the relationship between the groove circumferential width of an inclination groove | channel, and an inclination angle. The figure which shows the state engraved so that two inclined grooves may always pass the grinding point which has the length of the same axial direction as the width | variety of a workpiece. The graph which shows the relationship between the inclination angle of an inclination groove | channel, and the number. The figure which shows the relationship between the inclination-angle of an inclination groove | channel, and the pitch of a grindstone circumferential direction. The figure which shows the relationship between the inclination angle of an inclination groove | channel, and the reduction rate of the area of a grinding surface. The figure which shows the state which press-molds the grindstone chip | tip with an inclined groove | channel. The figure which shows the process of manufacturing an inclined grooved grindstone. The figure which shows a groove processing apparatus. The figure which shows the ratio which the grinding resistance and profile precision of a normal direction improve with a grindstone with an inclined groove | channel. The plane conceptual diagram of the type | mold which press-molds the grindstone chip | tip with a sloping groove in 2nd Embodiment. The side surface conceptual diagram shown broken. The figure which shows the process of manufacturing the grindstone with the same inclination groove | channel. The figure which shows the grindstone chip containing a hole-shaped recessed part in 3rd Embodiment. The figure which shows the grinding surface in which the same several hole-shaped recessed part was provided. The figure which shows the process of manufacturing the grindstone with the same hole-shaped recessed part. The figure which shows the grindstone chip | tip with a hole-shaped recessed part in 4th Embodiment. The figure which shows the process of manufacturing the grindstone with the same hole-shaped recessed part.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings. FIG. 1 shows a grindstone 10 including a segment type grindstone tip 11 produced by the production method of the first embodiment. The grindstone tip 11 of the grindstone 10 is an abrasive grain in which superabrasive grains are bonded by vitrified bonds. The layer 12 is formed on the outer peripheral side, and the base layer 13 that does not contain superabrasive grains is integrally formed so as to overlap the inside of the abrasive grain layer 12. In the grindstone 10, a plurality of arc-shaped grindstone chips 11 composed of an abrasive grain layer 12 and an underlayer 13 are arranged on the outer peripheral surface of a disk-shaped core 14 formed of a metal such as iron or aluminum, or a resin. The base layer 13 is configured to be adhered to the core 14 with an adhesive on the bottom surface. The grindstone 10 is attached by a core 14 to a grindstone shaft 32 that is supported on a grindstone base 31 of a grinder 30 shown in FIG. A workpiece W is rotatably supported on the workpiece support device 33 of the grinding machine 30, and the grinding surface 15 formed on the abrasive layer 12 of the grindstone 10 by the advance of the grindstone table 31 is applied to the workpiece W at a grinding point P. The outer peripheral surface of the workpiece W is ground by abutting with the above.

FIG. 3 shows an arc-shaped grindstone tip 11, and the abrasive grain layer 12 is formed by bonding superabrasive grains 16 such as CBN and diamond with a vitrified bond 17 to a thickness of 3 to 7 mm. For adjustment, particles such as aluminum oxide (Al ₂ O ₃ ) may be mixed as an aggregate instead of superabrasive grains. The underlayer 13 is obtained by bonding the underlayer particles 19 with a vitrified bond 17 to a thickness of 2 to 4 mm. When vitrified bond 17 is employed, the chip characteristics are excellent due to the characteristics of the pores, and the sharpness is improved, so that the amount of grinding wheel wear can be reduced and grinding can be performed to a good surface roughness. However, as the binder, in addition to the vitrified bond 17, a resin bond or a metal bond can be used.

  As shown in FIG. 4, the grinding surface 15 of the grindstone 10 has a plurality of inclined grooves 20 having a width b inclined with respect to the grindstone axis O, and at least one inclined groove 20 regardless of the rotational phase of the grindstone 10. It is engraved so as to pass the grinding point P up and down. As described above, when at least one inclined groove 20 always passes through the grinding point P, the dynamic pressure generated between the grinding surface 15 and the workpiece W by the grinding liquid supplied to the grinding point P is reduced at the grinding point. The workpiece W is released from both above and below, and the workpiece W is not displaced in a direction away from the grindstone 10 to increase the workpiece size, so that the grinding accuracy, particularly roundness, is improved. If at least one inclined groove 20 does not always pass through the grinding point P, the dynamic pressure is not released below the grinding point P if the inclined groove 20 is opened only above the grinding point P. Similarly, if the inclined groove 20 is opened only downward, the dynamic pressure of the grinding fluid is not released above the grinding point P. The inclined groove 20 is carved into the grinding surface 15 through both side surfaces 21 and 22 of the abrasive grain layer 12 perpendicular to the grinding wheel axis O.

  The conditions for easily creating the inclined groove 20 that can effectively prevent the generation of dynamic pressure of the grinding fluid supplied to the grinding point P and ensure high grinding accuracy and a long grinding wheel life will be described below. Street. Regardless of the rotational phase of the grindstone 10, the inclined groove 20 should pass at least one, preferably two or more grinding points P within the width of the workpiece W, that is, the length of the grinding point P in the axial direction. The groove circumferential width c, which is the width of the inclined groove 20 in the grinding wheel circumferential direction, is preferably shorter because the interval between the superabrasive grains 16 exposed on the grinding surface 15 is increased by the groove circumferential width c. In order to reduce the number of processing steps, it is better that the number of grooves is small. The pitch of the inclined grooves 20 in the circumferential direction of the grindstone is preferably longer because the pitch between the inclined grooves 20 is difficult to process and the strength of the grindstone tip 11 is reduced. It is better not to make the total area of the inclined grooves 20 too large since increasing the size will decrease the number of superabrasive grains 16 involved in grinding and increase the amount of grinding wheel wear.

  In consideration of these conditions, for example, a method for determining the number n of the inclined grooves 20 and the inclination angle α, which are suitable when the workpiece W having a width of 15 mm is plunge cut ground with the grindstone 10 having an outer diameter of 350 mm, will be described below. . The inclination angle α is an angle formed between the inclined groove 20 and the side surface 21 of the abrasive grain layer 12, in other words, the circumferential direction of the grindstone, and the length of the grinding point P in the axial direction is 15 mm, which is the same as the width of the workpiece W. .

  The width b in the groove normal direction of the inclined groove 20 is about 1 mm in order to reduce the groove circumferential width c, which is the length of the inclined groove 20 in the circumferential direction of the grindstone in consideration of the strength of the grindstone for grinding. It is good to do. The relationship between the groove circumferential width c and the inclination angle α of the inclined groove 20 is as shown in FIG. 5. When the inclination angle α is larger than about 15 degrees, the groove circumferential width c is reduced, and superabrasion by the inclined groove 20 is performed. The spread of the interval between the grains 16 can be kept small.

  As shown in FIG. 6, for example, in the range d where the outer peripheral grinding surface 15 (outer diameter 350 mm) of the grindstone 10 is in contact with the workpiece W (width 15 mm), for example, two inclined grooves 20 are involved in the rotational phase of the grindstone 10. When the grinding point P having the same length in the axial direction as the width of the workpiece W is passed, the relationship between the inclination angle α of the inclined groove 20 and the number n is shown in FIG. FIG. 8 shows the relationship between the pitch 20 in the circumferential direction of the grindstone 20 and FIG. 9 shows the relationship between the inclination angle α and the area reduction rate of the grinding surface 15 by the inclined grooves 20. As is clear from FIG. 8, when the inclination angle α is smaller than about 15 degrees, the pitch p in the circumferential direction of the grindstone of the inclined groove 20 becomes sufficiently large, so that the processing of the inclined groove 20 is not hindered. Further, as shown in FIG. 9, when the inclination angle α is made smaller than about 15 degrees, the reduction rate of the area of the grinding surface 15 by the inclined grooves 20 can be kept small. Further, as shown in FIG. 7, when the inclination angle α is about 15 degrees, the number n of the inclined grooves 20 can be reduced. Considering these, it is preferable to set the inclination angle α to a value in the vicinity of 15 degrees.

  In this way, when the workpiece W having a width of 15 mm is subjected to plunge cut grinding with the grindstone 10 having an outer diameter of 350 mm, the width of the workpiece W, that is, within the length in the axial direction of the grinding point P, regardless of the rotational phase of the grindstone 10. The specifications of the inclined groove 20 determined so that at least two inclined grooves 20 pass through the grinding point P are, for example, a groove width b of 1 mm, a groove depth h of 6 mm, an inclination angle α of 15 degrees, and the number It is preferable that n is 39 and the circumferential pitch p is about 28.1 mm.

  For example, as shown in FIG. 6, a grindstone chip having a width of 30 mm is formed on the grinding surface 15 of the grindstone 10 having a width twice as large as that of the workpiece W having a width of 15 mm. In FIG. 11, five inclined grooves 20 are engraved at a circumferential pitch p (about 28.1 mm). As an example in which the five inclined grooves 20 are formed in the grindstone tip 11, the front half 20f and the rear half 20r in the grindstone rotation direction of the inclined groove 20 are the circumferential rear end face 11r and the front end face 11f of the grindstone tip 11. Each center portion is engraved at an inclination angle of 15 degrees toward both side surfaces 21 and 22, and the center portion 20 m of the inclined groove 20 is engraved therebetween, and the grindstone chip 11 is further affixed to the core 14. In this case, both end portions 20e of the inclined groove 20 that are continuous with the central portion 20m of the front and rear grindstone chips 11 are formed. On the center line in the width direction of the grindstone chip 11, the ends of the front half 20f and the rear half 20r and the center 20m of the inclined groove 20 are located, so that the circumferential length of the grindstone chip 11 is slightly less than two pitches. Is about 56 mm, which is short.

  Next, in the method for manufacturing the grindstone chip 11 (first embodiment), as shown in FIG. 10A, the lower die 42 is fitted to the inner bottom portion of the rectangular outer die 41, An arcuate concave surface 42 a corresponding to the arc surface of the grindstone chip 11 having the outer diameter of the grindstone 10 is formed on the upper surface of the lower die 42. The lower mold 42 is filled with an abrasive layer powder 44 in which the superabrasive grains 16, the vitrified bond 17 and the aggregate 18 constituting the abrasive layer 12 are mixed, and the thickness of the abrasive layer powder 44 is increased. Is leveled (step 51 in FIG. 11). In this state, as shown in FIG. 10B, the pressing die as the first upper die 45 is lowered along the inner surface of the outer die 41, and the abrasive grain layer powder 12 is temporarily pressed by pressing the abrasive grain layer powder 44. Is temporarily formed into an arc shape (step 52).

  Subsequently, as shown in FIG. 10C, the ground layer powder 46 including the ground particles 19 is filled on the upper side of the temporary press-molded abrasive grain layer 12, and the thickness of the ground layer powder 46. Are leveled (step 53). In this state, as shown in FIG. 10 (d), the second upper mold 47 is lowered along the inner surface of the outer mold 41, and the ground layer powder 46 and the abrasive layer powder 44 are pressed simultaneously. . As a result, the base layer 13 is overlapped with the inner side of the abrasive grain layer 12 and is integrally press-molded to form the arc-shaped grindstone chip 11 (step 54). Thereafter, the second upper die 47 is raised, and the grindstone tip 11 is released from the outer die 41 and the lower die 42 (step 55).

  The grindstone chip 11 before firing is placed and clamped on an arc-shaped jig having the same radius as the bottom surface of the base layer 13, and the five inclined grooves 20 described above are circularly formed on the abrasive grain layer 12 of the grindstone chip 11. From the grinding surface 15 to the base layer 13 at a circumferential pitch p, the linear machining is performed by machining (step 56). The machining can be performed using a known groove processing device 60 shown in FIG. In the grooving device 60, for example, a grindstone base 63 that supports a grindstone shaft 62 on which a grindstone 61 for grooving is mounted in a horizontal plane so that the grindstone shaft 62 can be driven to rotate about an axis parallel to the Z axis is provided on a column 64 in the vertical Y axis direction. The column 64 is placed on the bed 65 so as to be movable in the Z-axis direction, and the work table 66 is opposed to the column 64 on the bed and is perpendicular to the Z-axis in the horizontal plane. It is mounted so as to be movable in the direction. A rotary table 67 is supported on the work table 66 so as to be indexable and rotatable about a vertical axis, and a spindle base 70 which supports a spindle 69 provided with a jig 68 so as to be capable of rotational positioning in a horizontal plane is fixed on the rotary table 67. Has been.

  In the processing of the inclined groove 20, the grinding wheel tip 11 is clamped with the jig 68 in contact with the arc surface of the base layer 13 with the abrasive grain layer 12 facing outward, and the circumferential rear end surface 11 r of the grinding wheel tip 11 is the rotational axis of the main shaft 69. The main shaft 69 is rotationally positioned so as to be positioned vertically upward. The rotary table 67 is indexed and rotated so that the axis of the main shaft 69 is inclined with respect to the Z axis by the inclination angle α of the inclined groove 20 so that the direction of the side surface of the grindstone 61 for grooving coincides with the direction of the inclined groove 20. The The column 64 is positioned in the Z-axis direction so that the grooving grindstone 61 is aligned with the front half 20 f of the inclined groove 20, and the lower end surface of the grooving grindstone 61 coincides with the bottom surface of the front half 20 f of the inclined groove 20. Then, the grindstone base 63 is lowered in the Y-axis direction and positioned. By grinding and feeding the work table 66 in the X-axis direction, the grooving grindstone 61 is linearly fed in the direction of the inclination angle α of the inclined groove 20 with respect to the pre-firing grindstone chip 11, and the abrasive grains of the pre-firing grindstone chip 11. In the layer 12, inclined grooves 20 that are inclined with respect to the circumferential direction of the grindstone are formed in a straight line by machining from the grinding surface 15 to the base layer 13 (see FIG. 3). Subsequently, the column 64 is indexed and moved in the Z-axis direction by the normal pitch of the inclined groove, and the above operation is repeated to engrave the central portion 20m, the rear half portion 20r, and both end portions 20e of the inclined groove 20. The

  The grindstone chip 11 provided with the inclined grooves 20 is removed from the jig 68 of the groove processing device 60 and fired in the furnace (step 57), and the production of the grindstone chip 11 is completed. Since the grindstone chip 11 is fired after the inclined groove 20 is processed, the superabrasive grains 16 exposed from the binder by machining are coated and bonded to the vitrified bond 17 melted at the time of firing, so that the holding power of the superabrasive grains 16 is increased. Is not reduced by machining. The 19 grindstone chips 11 thus fired are affixed to the outer peripheral surface of the core 14 so that the inclined grooves 20 always pass at least two grinding points P regardless of the rotational phase of the grindstone 10 (step 58).

  Next, the operation of the grindstone 10 produced by the method for producing the inclined grooved grindstone of this embodiment will be described. The grindstone 10 is mounted on a grindstone shaft 32 supported on a grindstone base 31 of a grinding machine 30 shown in FIG. 2 by a core 14 and is driven to rotate, and the workpiece W is applied to a workpiece support device 33 including a headstock and a tailstock. It is supported and rotated. The coolant is supplied from the coolant nozzle 35 attached to the grindstone cover 34 to the grinding point P between the grindstone 10 and the workpiece W, and the grindstone base 31 is ground and fed toward the workpiece W. Is ground. In this case, since the plurality of inclined grooves 20 that are inclined with respect to the circumferential direction of the grindstone always pass at least two grinding points P regardless of the rotational phase of the grindstone 10, the grinding fluid supplied to the grinding point P is ground. The dynamic pressure generated between 15 and the workpiece W can be released from above and below the grinding point P. As a result, the workpiece W is not displaced in the direction away from the grindstone 10 to increase the size of the workpiece W, and the grinding accuracy, particularly roundness, can be increased.

  As an example of the grinding process, CBN abrasive grains having a grain size of # 120 are bonded by vitrified bond 17 with a concentration of 150 to form the abrasive grain layer 12, and the abrasive grain layer 12 does not contain superabrasive grains. Normal line when a hardened steel cam (workpiece W) having a width of 15 mm is ground by a grindstone having an outer diameter of 350 mm, on which a grindstone tip 11 formed integrally with the formation 13 is stuck to a steel core 14 Assuming that the grinding resistance in the direction and the profile accuracy are 100, 39 inclined grooves 20 having a groove width b of 1 mm, a groove depth h of 6 mm, and an inclination angle α of 15 degrees are formed on the outer peripheral grinding surface 15 of the grindstone. When the same cam was ground with the inclined grooved grindstone 10, the grinding resistance in the normal direction was reduced to 77 and the profile accuracy was improved to 20 (see FIG. 13).

In the above embodiment, when the inclined groove 20 is machined by the groove processing device 60, the inclined grinding groove 61 is engraved by linearly feeding the grooving grindstone 61, but the grindstone chip 11 before firing is grooved. The main shaft 69 is attached to the main shaft 69 via a jig 68, and the axis of the main shaft 69 is inclined with respect to the Z axis so that the direction of the side surface of the grooving grindstone 61 coincides with the inclination angle of the inclined groove 20. The rotary table 67 is indexed and rotated so as to incline at an angle α, and the column 64 and the work table 66 are moved in the Z-axis and X-axis directions in conjunction with the rotation of the main shaft 69 to spiral the abrasive grain layer 11. The groove 20 may be formed from the ground surface 15 to the underlayer 12.
In the above-described embodiment, the width of the workpiece W is smaller than the width of the grindstone 10, and the specifications of the inclined groove 20 are obtained assuming that the length of the grinding point P in the axial direction is equal to the width of the workpiece W. However, when the width of the workpiece W is larger than the width of the grindstone 10, the specifications of the inclined groove 20 are obtained assuming that the length of the grinding point P in the axial direction is equal to the width of the grindstone.

  In the above embodiment, at least two grinding points P are passed through the inclined grooves 20 regardless of the rotational phase of the grinding stone 10 in the fired grindstone chips, but at least one grinding point P is passed. You may do it.

  In the above embodiment, the inclined groove 20 is engraved in the abrasive grain layer 12 by machining from the grinding surface 15 to the underlayer 13, but only the abrasive layer 12 at a depth without reaching the underlayer 13. May be engraved.

  Further, in order to produce a grindstone with a slanted groove for effectively introducing the grinding liquid along the slanted groove to the grinding point, the grindstone periphery of the pre-firing grindstone chip is formed as in this embodiment. An inclined groove inclined with respect to the direction is engraved by machining, a pre-fired grindstone chip in which the inclined groove is engraved, and a plurality of the fired grindstone chips are stuck on the core. Good.

Next, a second embodiment of the present invention will be described with reference to the drawings. Since the configuration of the grindstone 10 including the segment type grindstone tip 11 manufactured by the manufacturing method of the second embodiment is the same as that of the first embodiment, the description thereof is omitted.
In this method of manufacturing the grindstone chip 11, the inclined groove 20 is formed on the grinding surface of the grindstone chip 11 by pressing. As shown in FIGS. 14 and 15, the lower die 82 is fitted to the inner bottom portion of the rectangular outer die 81, and an arc shape for press-molding the arc surface of the grindstone chip 11 having the outer diameter of the grindstone 10. A concave surface 82 a is formed on the upper surface of the lower die 82. The lower mold 82 has a plurality of mounting grooves corresponding to the inclined grooves 20, and the inclined groove forming plate 83 for forming the plurality of inclined grooves 20 is protruded upward from the concave surface 82a. It is detachably fitted in the groove. These inclined groove forming plates 83 are made of, for example, carbon, and stand on the concave surface 82a so as to incline with respect to the direction of the grindstone circumferential direction when the grindstone chip 11 to be molded is affixed to the core 14, respectively. Established.

  As shown in FIG. 16 (a), the abrasive layer powder 44 in which superabrasive grains, binder, aggregate and the like constituting the abrasive layer 12 are mixed is formed on the lower mold 82 with a plurality of inclined groove forming plates 83. It is filled up further and leveled so that the thickness of the abrasive layer powder 44 is uniform.

  Next, as shown in FIG. 16B, the upper die 85 is lowered into the outer die 81, and the abrasive layer powder 44 is temporarily pressed to temporarily form the abrasive layer in an arc shape. At this time, a temporary inclined groove is formed on the surface of the abrasive grain layer formed on the lower mold 82 side.

  Next, as shown in FIG. 16C, the ground layer powder 46 including the ground particles 19 is filled on the upper side of the temporarily pressed abrasive layer powder 44 to form the ground layer powder 46. Are leveled so that the thickness is uniform.

  Next, as shown in FIG. 16 (d), the upper mold 85 is lowered into the outer mold 81, and the underlayer powder 46 and the abrasive layer powder 44 are pressed simultaneously, so that the underlayer 13 is ground. The arc-shaped grindstone chip 11 is press-molded by being integrally formed on the inner side of the grain layer 12. At this time, the inclined groove forming plate 83 is pressed so as to penetrate the abrasive layer 12 and reach the base layer 13.

  Next, the upper die 85 is raised, and the grindstone tip 11 is released from the outer die 81 and the lower die 82. When the grindstone chip 11 is removed from the lower mold 82, the plurality of inclined groove forming plates 83 are released from the lower mold 82 together with the grindstone chip 11 while penetrating the abrasive grain layer 12 of the grindstone chip 11.

Next, the grindstone chip 11 in a state where the plurality of inclined groove forming plates 83 penetrate the abrasive grain layer 12 is placed on a table and fired. Firing is performed at 700 to 1000 ° C., for example, in the atmosphere when vitrified bond is used as a binder as in this embodiment. Since carbon is generally burned off at about 700 ° C., the inclined groove forming plate 83 made of carbon is burned off and removed during this baking. In this way, the manufacture of the grindstone chip 11 is completed.
The fired grindstone tip 11 is affixed to the outer peripheral surface of the core 14 so that the inclined groove 20 passes through at least two grinding points P regardless of the rotational phase of the grindstone 10.

  According to such a method for manufacturing a grindstone, the ground layer 13 is stacked on the abrasive grain layer 12 filled so as to be in contact with the grinding surface forming portion (the lower die 82), and is integrally press-molded in the circumferential direction of the grindstone. Since the pre-firing grindstone chip provided with the inclined grooves 20 inclined with respect to the surface is formed, the step of merely providing the inclined grooves 20 can be omitted, and the inclined groove 20 forms the abrasive grain layer of the grindstone chip 11 after firing. As in the case of being engraved by machining, the durability of holding the superabrasive grains firmly without reducing the holding power of the superabrasive grains exposed to the grinding surface at the side walls of the inclined grooves 20 by machining. Can be manufactured easily at low cost.

  Further, since the inclined groove 20 penetrates the abrasive grain layer 12 and is recessed by press molding from the ground surface to the base layer 13, the entire thickness of the abrasive grain layer 12 can be effectively used for grinding. , The life of the wheel will be longer.

Further, since the inclined groove forming plate 83 can be burned down by the high temperature when the grindstone chip 11 is fired, the step of removing the inclined groove forming plate 83 from the grindstone chip 11 before firing can be omitted. Production efficiency can be improved.
Since the operation of the grindstone 10 manufactured by the above manufacturing method is the same as that of the first embodiment, the description thereof is omitted.

  Next, a third embodiment of the present invention will be described with reference to the drawings. About the structure of the grindstone 10 including the segment type grindstone tip 11 manufactured by the manufacturing method of the third embodiment, instead of the inclined groove 20 on the grinding surface 15 of the grindstone, as shown in FIGS. The difference from the first embodiment is that a plurality of hole-shaped recesses 90 are formed so as to penetrate the abrasive layer 12 and reach the foundation layer 13. The other configurations are the same and will not be described.

  In this method of manufacturing the grindstone chip 11, a plurality of hole-shaped recesses 90 are formed on the grinding surface of the grindstone chip 11 by pressing. As shown in FIG. 19, a lower die 92 is fitted to the inner bottom of a rectangular outer die 91, and an arcuate concave surface 92 a for press-molding an arcuate surface of a grindstone chip 11 having an outer diameter of the grindstone 10. Is formed on the upper surface of the lower die 92. The lower die 92 has a plurality of mounting holes corresponding to the hole-shaped recesses 90, and the pin member 93 for forming the plurality of hole-shaped recesses 90 is protruded upward from the concave surface 92a. It is detachably fitted in the hole. These pin members 93 are made of, for example, carbon.

  First, as shown in FIG. 19A, the abrasive layer powder 44 in which the superabrasive grains, the binder, the aggregate and the like constituting the abrasive layer 12 are mixed is formed on the lower die 92 with a plurality of pin members 93. It is filled up further and leveled so that the thickness of the abrasive layer powder 44 is uniform.

  Next, as shown in FIG. 19 (b), the first upper die 95 in which a plurality of relief holes 94 corresponding to the plurality of pin members 93 are vertically drilled is lowered into the outer die 91, and an abrasive layer The abrasive powder 44 is temporarily pressed to temporarily form the abrasive grain layer 12 into an arc shape. At this time, the pin member 93 penetrates the abrasive grain layer 12 and slightly protrudes upward and fits into the escape hole 94.

  Next, as shown in FIG. 19 (c), the ground layer powder 46 in which the ground particles 19 and the binder are mixed is above the plurality of pin members 93 above the temporarily pressed abrasive grain layer 12. And the base layer powder 46 is leveled so that the thickness thereof is uniform.

  Next, as shown in FIG. 19 (d), the second upper die 97, in which no escape hole is formed, is lowered into the outer die 91, and the underlayer powder 46 and the abrasive layer powder 44 ( The abrasive layer 12) is simultaneously pressed, the underlayer 13 is formed integrally with the inner side of the abrasive layer 12, and the arc-shaped grindstone chip 11 is press-molded. At this time, the pin member 93 is pressed so as to penetrate the abrasive layer 12 and reach the base layer 13.

  Next, the second upper mold 97 is raised, and the grindstone tip 11 is released from the outer mold 91 and the lower mold 92. When the grindstone chip 11 is removed from the lower mold 92, the plurality of pin members 94 are separated from the lower mold 92 together with the grindstone chip 11 while penetrating the abrasive grain layer 12 of the grindstone chip 11.

Next, the grindstone chip 11 with the plurality of pin members 94 penetrating the abrasive grain layer 12 is placed on a table and fired. Firing is performed at 700 to 1000 ° C., for example, in the atmosphere when vitrified bond is used as a binder as in this embodiment. In general, carbon is burned off at about 700 ° C., so the carbon pin member 94 is burned off and removed during this firing. In this way, the manufacture of the grindstone chip 11 is completed.
The fired grindstone chip 11 is stuck to the outer peripheral surface of the core 14 so that at least some of the hole-shaped recesses 90 overlap the grinding point P of the grindstone 10 regardless of the rotational phase of the grindstone 10.

The operation of the grindstone 10 manufactured by the above manufacturing method will be described below.
When the workpiece W is ground using the grindstone according to the present embodiment, the dynamic pressure of the grinding fluid supplied to the grinding point P is released by the plurality of hole-shaped recesses 90 overlapping the grinding point P. In addition, since the grinding liquid enters the plurality of hole-shaped recesses 90, the grinding liquid is sufficiently supplied to the grinding point P to sufficiently remove the grinding heat, and the cutting waste falls into the plurality of hole-shaped recesses 90. As a result, cutting waste is improved and high-speed grinding is possible, thereby improving the grinding efficiency. Since other operations are the same as those in the first embodiment, description thereof will be omitted.

  Next, a fourth embodiment of the present invention will be described with reference to the drawings. About the structure of the grindstone 10 containing the segment type grindstone chip | tip 11 manufactured with the manufacturing method of 4th Embodiment, as shown in FIG. 20, the several hole-shaped recessed part 100 is provided in the grinding surface 15 of a grindstone. The third embodiment is different from the third embodiment in that it is formed not only through the grain layer 12 but also through the base layer 13. The other configurations are the same and will not be described.

  The manufacturing method of this grindstone chip 11 is demonstrated based on FIG. First, as shown in FIG. 21 a, an arcuate convex surface 102 a is the same diameter as the outer diameter of the core 14 of the grindstone 10 on the upper surface of the lower mold 102 fitted to the inner bottom portion of the rectangular outer mold 101. Is formed. A plurality of insertion holes 102b are vertically formed in the lower mold 102 so as to correspond to the plurality of hole-shaped recesses 100, and a plurality of carbon pin members 103 for forming the plurality of hole-shaped recesses 100 are convex surfaces. It is inserted into the fitting insertion hole 102b so as to protrude upward from 102a. Then, the underlayer powder 46 is filled and leveled on the lower mold 102 to above the plurality of pin members 103.

  Next, as shown in FIG. 21 b, the underlayer powder 46 is temporarily pressed by the upper mold 105 in which a plurality of relief holes 104 corresponding to the plurality of pin members 103 are vertically drilled, so that the underlayer 13 is formed into a circular shape. Temporarily mold into an arc. At this time, the pin member 103 penetrates through the underlayer powder 46 and slightly protrudes upward to fit into the escape hole 104.

  Next, as shown in FIG. 21c, a pin projecting jig 109 having a projecting pin 106 projecting corresponding to the fitting insertion hole 102b is brought into contact with the outer mold 101 and the lower mold 102 from below. The pin member 103 is protruded and moved upward by the length of the pin 106.

  Next, as shown in FIG. 21 d, the abrasive layer powder 44 is filled above the plurality of pin members 103 above the temporary press-molded powder 46, and the abrasive layer powder 44. Are leveled so as to have a uniform thickness.

  Next, as shown in FIG. 21 e, the abrasive layer powder 44 and the underlayer powder 46 are simultaneously pressed by the upper mold 105 so that the abrasive layer 12 overlaps the outside of the underlayer 13 and is integrated. The formed arcuate grindstone chip 11 is press-molded. At this time, the pin member 103 penetrates the base layer 13 and the abrasive grain layer 12 and slightly protrudes upward and fits into the relief hole 104, thereby forming a plurality of hole-shaped recesses 100 penetrating the grinding stone chip 11.

  Next, the upper die 105 is raised, and the grindstone tip 11 is released from the outer die 101 and the lower die 102. When the grindstone chip 11 is removed from the lower mold 102, the plurality of pin members 103 are separated from the lower mold 102 together with the grindstone chip 11 while penetrating the grindstone chip 11.

Next, the grindstone chip 11 with the plurality of pin members 103 inserted therein is placed on a table and fired. Firing is performed at 700 to 1000 ° C., for example, in the atmosphere when vitrified bond is used as a binder as in this embodiment. At this time, since carbon is generally burned off at about 700 ° C., the carbon pin member 103 is burned off and removed during firing. In this way, the manufacture of the grindstone chip 11 is completed. The baked grindstone chip 11 is attached to the outer peripheral surface of the core 14.
Since the operation of the grindstone 10 manufactured by the above manufacturing method is the same as that of the third embodiment, the description thereof is omitted.

  In the above embodiment, the inclined groove forming plate and the pin member are made of carbon. However, the present invention is not limited to this, and any material may be used as long as it is burned out when the grindstone chip is fired, preferably a material burned down at a temperature lower than the firing temperature. For example, it may be made of a hard resin, and in this case, as in the case of carbon, it can be burned off when the grindstone chip is fired. Further, it may be made of metal such as steel. In this case, it is necessary to remove by grinding or the like before the grinding of the grinding wheel tip, but as in the case where the inclined groove or the hole-like concave portion is drilled in the abrasive layer of the grinding stone chip after firing, In the side wall part of the inclined groove and the inner wall part of the hole-shaped recess, the holding power of the superabrasive grains exposed to the grinding surface is not reduced by machining, and a highly durable grindstone that holds the superabrasive grains firmly can be easily reduced. Can be manufactured at cost.

  In addition, although the grindstone chip is press-formed in an arc shape, the shape is not limited to this, and may be, for example, a flat plate shape. In this case, the plate-shaped grindstone chip before firing is placed on a table having the same shape and dimension as the outer diameter of the grindstone core, and is fired following the outer diameter of the table.

  DESCRIPTION OF SYMBOLS 10 ... Whetstone, 11 ... Whetstone tip, 12 ... Abrasive grain layer, 13 ... Underlayer, 14 ... Core, 15 ... Grinding surface, 16 ... Superabrasive grain, 17 ... Vitrified bond, 20 ... Inclined groove, 21, 22 ... Side, 30 ... Grinding machine, 31 ... Grinding wheel base, 32 ... Grinding wheel shaft, 33 ... Workpiece support device 35 ... Coolant nozzle, 41, 81, 91, 101 ... Outer die, 42, 82, 92, 102 ... Lower die, 45, 85, 95 ... First upper die, 47, 87 97 ..., second upper mold, 60 ... groove processing device, 61 ... grindstone for grinding (tool), 68 ... jig, 69 ... spindle, 83 ... inclined groove forming Plate, 93, 103 ... Pin member, 105 ... Upper mold, P ... Grinding point, W ... Workpiece, [alpha] ... Inclination angle.

Claims (1)

A plurality of grindstone chips comprising an abrasive layer containing superabrasive grains and an underlayer are affixed to a core mounted on a grindstone shaft that is rotatably supported around a rotation axis on a grindstone table of the grinding machine, In a method for manufacturing a grindstone, wherein a grinding surface formed in a grain layer contacts and grinds a workpiece supported by a workpiece support device of the grinding machine so as to be rotationally driven at a grinding point.
Carbon is provided in a plurality of mounting grooves that are recessed in the surface of the grinding surface molding part of a press mold for molding the grinding wheel chip, and in which a plurality of inclined groove molding plates are respectively fitted so as to protrude from the surface of the grinding surface molding part. A plurality of inclined groove forming plates made of resin or resin are formed so as to be detachable so as to incline with respect to the direction of the grindstone circumferential direction when the grindstone chip to be molded is affixed to the core. Plate standing process,
The press mold is filled with a powder for an abrasive layer in which a plurality of superabrasive grains and a binder are mixed, and the powder for the base layer in which the base particles and the binder are mixed is used as the powder for the abrasive layer. A powder filling process of filling and filling
A press molding step of integrally pressing the abrasive layer powder and the underlayer powder so that the formed underlayer is not separated by the inclined groove forming plate;
The pre-firing grindstone chip in which the abrasive layer and the base layer are integrally formed by the press molding, and the plurality of inclined groove forming plates penetrates at least the abrasive layer , the plurality of inclined groove forming plates And a mold release step for releasing from the press mold,
While firing the pre-firing grindstone chip, the slanted groove forming plate is burned off to form a post-firing grindstone chip in which a plurality of slanted groove-shaped recesses inclined with respect to the circumferential direction of the grindstone are provided in the abrasive layer. A firing step;
The manufacturing method of the grindstone with a recessed part provided with.

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