JP4948122B2 - Whetstone with inclined grooves - Google Patents

Description

The present invention relates to the inclined groove containing abrasive stones forming the inclined grooves in the grinding chips segment type affixed to the 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 rotation axis, and a predetermined width is provided on the outer peripheral surface of the abrasive layer. Patent Document 1 discloses a grooved grindstone in which an inclined groove having a depth 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. Increase the grinding efficiency.
JP 2000-354969 (paragraphs [0007], [0026], FIG. 1)

  However, according to the above-mentioned grooved grindstone, the inclined grooves are engraved to both end surfaces of the abrasive layer perpendicular to the rotation axis, and each end surface and the side wall surface of the inclined groove form an acute angle. There is a problem that the strength of is insufficient at the acute angle portion, and cracking or chipping of the abrasive layer is likely to occur due to grinding resistance.

  The present invention has been made in view of the conventional problems, and it is possible to easily prevent the abrasive grain layer from being cracked or chipped by the inclined grooves formed to be inclined in the circumferential direction of the grindstone. That's it.

In order to solve the above-described problem, the configuration of the invention according to claim 1 is a polishing machine including a superabrasive grain in a core mounted on a grindstone shaft that is rotatably supported around a shaft line on a grindstone base of a grinding machine. A plurality of grindstone chips having a grain layer and side end faces parallel to the circumferential direction of the grindstone are affixed, and the grinding surface formed on the abrasive grain layer can be rotationally driven to the workpiece support device of the grinder In a grindstone that grinds by contacting a supported workpiece at a grinding point, the grindstone tip is inclined with respect to the circumferential direction of the grindstone, and an end is engraved to the front side of each side of the grindstone tip. An inclined groove main body occupying a main portion of the inclined groove, and an inclined groove main body formed on the grindstone chip adjacent to the grindstone chip in the front of the grindstone in the rotation direction, and one side of the side end surfaces on both sides A rear end portion engraved to the front of the end surface and the grindstone tip By the rotation direction rear continuously inclined groove body portion formed in the adjacent grinding chips, the front end portion which is engraved to just before the other end face of the side end surfaces of the both sides, are formed is there.

The structural feature of the invention according to claim 2 is characterized in that the core mounted on the grindstone shaft that is rotatably supported around the axis on the grindstone table of the grinder has an abrasive layer containing superabrasive grains, and A workpiece in which a plurality of grindstone chips having side end surfaces parallel to the circumferential direction of the grindstone are affixed to each other, and a grinding surface formed on the abrasive grain layer is rotatably supported on a workpiece support device of the grinder. In a grindstone that abuts at a grinding point and grinds, the grindstone tip is inclined with respect to the circumferential direction of the grindstone, and an end is adjacent to an inclined groove that is engraved to the front side of each side of the grindstone tip. Between the inclined grooves and at the center of at least one of the front end face and the rear end face parallel to the grinding wheel axial direction, grooves each formed so as to extend in the circumferential direction of the grinding stone are formed. That is.

According to the first aspect of the present invention, in the grindstone in which a plurality of grindstone chips having an abrasive layer containing superabrasive grains are attached to the core, each grindstone chip is provided with an inclined groove that is slanted with respect to the circumferential direction of the grindstone. It is installed. With this inclined groove, the dynamic pressure generated in the grinding fluid supplied to the grinding point can be released, and the workpiece is not displaced in the direction away from the grindstone to increase the workpiece size. In particular, the roundness can be increased. Since the end of each inclined groove is engraved to the front of each side end face parallel to the circumferential direction of the grindstone, the side end face and the side wall face of the inclined groove reduce the strength. It is possible to prevent the abrasive grain layer from being cracked or chipped by the grinding resistance without forming.
And the said grindstone chip is formed with the inclined groove main-body part, and the rear-end part and front-end part which follow the inclined groove main-body part each formed in the grindstone chip adjacent to front and back. These inclined groove main body part, rear end part, and front end part are portions where adjacent inclined grooves overlap each other in the circumferential direction of the grindstone when continuously attached to the core. It is possible to form an inclined groove that always passes through one grinding point. In addition, since each front end and rear end are engraved up to the front of the side end surface parallel to the grinding wheel circumferential direction of the grindstone tip, the side end surface and the side wall surface of the inclined groove do not form an acute angle that reduces the strength. In addition, it is possible to form an inclined groove that prevents the abrasive layer from being cracked or chipped by grinding resistance. In addition, since a grindstone can be formed by sticking a patterned grindstone tip of the same shape to the core in the circumferential direction of the grindstone, it becomes easy to ensure product quality, and it is possible to reduce production costs and production schedules. .

According to the invention of claim 2, in the grindstone in which a plurality of grindstone chips having an abrasive layer containing superabrasive grains are attached to the core, each grindstone chip has an inclined groove that is slanted with respect to the circumferential direction of the grindstone. It is installed. With this inclined groove, the dynamic pressure generated in the grinding fluid supplied to the grinding point can be released, and the workpiece is not displaced in the direction away from the grindstone to increase the workpiece size. In particular, the roundness can be increased. Since the end of each inclined groove is engraved to the front of each side end face parallel to the circumferential direction of the grindstone, the side end face and the side wall face of the inclined groove reduce the strength. It is possible to prevent the abrasive grain layer from being cracked or chipped by the grinding resistance without forming.
Even when grinding a workpiece having a grinding surface whose width is narrower than the separation distance between adjacent inclined grooves in the grinding wheel axis direction, the dynamic pressure generated in the supplied grinding fluid by the grooves extending in the circumferential direction of the grinding wheel. Can be released.

  An embodiment of a grindstone with an inclined groove according to the present invention will be described below with reference to the drawings. FIG. 1 shows a grindstone including a segment type grindstone tip, and FIG. 2 shows a grinder on which the grindstone is mounted.

  In the grindstone tip 11 of the grindstone 10, an abrasive layer 12 in which superabrasive grains are bonded by vitrified bonds is formed on the outer peripheral side, and an underlayer 13 not including the superabrasive layer is laminated on the inside of the abrasive grain layer 12 to be integrated. Is formed. In the grindstone 10, a plurality of arc-shaped grindstone chips 11 each composed of an abrasive 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 bottom surface of the formation 13 is configured to be affixed to the core 14 with an adhesive. 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 to a thickness of 3 to 5 mm with vitrified bonds 17. For adjustment, particles such as aluminum oxide (Al2O3) may be mixed as an aggregate instead of superabrasive grains. The underlayer 13 is formed by bonding the underlayer particles 19 with a vitrified bond 17 to a thickness of 1 to 3 mm. When vitrified bond 17 is employed, the chip characteristics are excellent due to the characteristics of the pores, and the sharpness becomes good, so that the grinding wheel can be ground to a good surface roughness by reducing the wear amount of the grindstone. However, as the binder, in addition to the vitrified bond 17, a resin bond or a metal bond can be used. Further, an inclined groove 20 to be described later is formed with a depth h that reaches the foundation layer 13 from the surface of the abrasive grain layer 12.

  As shown in FIG. 4, the grinding surface 15 of the grindstone 10 has a plurality of inclined grooves 20 having a width b that is inclined with respect to the circumferential direction of the grindstone, 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.

  Further, as shown in FIG. 5, each grindstone tip 11 has side end faces 21 and 22 parallel to the circumferential direction, an inclined groove main body portion 20 a that occupies the main portion of the inclined groove 20, and a grindstone on the grindstone chip 11. The rear end portion 20b engraved to the front side of one side end face 22 is continuous with the inclined groove main body portion 20a formed in the adjacent grindstone tip 11 in the forward direction of the rotation 10 and the rotation of the grindstone 10 on the grindstone tip 11. A front end portion 20c is formed which is continuous with the inclined groove main body portion 20a formed in the grindstone chip 11 adjacent to the rear in the direction and is engraved up to the front side of the other side end surface 21. Since these inclined groove main body 20a, rear end 20b and front end 20c are continuously affixed to the core 14, the adjacent inclined grooves 20 become portions overlapping each other in the circumferential direction of the grindstone. Regardless of the rotational phase of 10, it is possible to form one inclined groove 20 that always passes up and down with respect to the grinding point P. In this way, when the inclined groove 20 always passes through the grinding point P, the dynamic pressure generated in the grinding fluid supplied to the grinding point P is released, and the workpiece W is displaced in a direction away from the grindstone 10 to be machined. The dimension is not increased, and the grinding accuracy, particularly roundness, is improved.

  In addition, each front end portion 20c and each rear end portion 20b of the inclined groove 20 are engraved up to the front end without reaching the side end faces 21 and 22 parallel to the circumferential direction of the grindstone of the grindstone tip 11. The inclined groove 20 that prevents the abrasive grain layer 12 from being cracked or chipped by grinding resistance is formed without forming an acute angle between the side end surfaces 21 and 22 and the side wall surfaces 23 and 24 of the inclined groove 20. can do. In addition, since the inclined groove main body 20a, the rear end 20b, and the front end 20c are formed, and the grindstone chip 11 that is patterned in the same shape is attached to the core 14 in the grindstone circumferential direction, the grindstone 10 is formed. Product quality can be easily ensured, manufacturing costs can be reduced, and manufacturing schedules can be shortened.

  Further, each grindstone chip 11 is provided with a groove 25 extending in the circumferential direction of the grindstone at the center of the front end face 26 and the rear end face 27 between the adjacent inclined grooves 20 and parallel to the grindstone axial direction. It is installed. These grooves 25 are engraved so as to form one groove 25 continuously with the grooves 25 formed on the adjacent grindstone chips 11 when the grindstone chips 11 are arranged and stuck on the core 14. Has been. This groove 25 is effective for releasing the dynamic pressure generated in the grinding fluid when grinding a workpiece W having a grinding surface with a width narrower than the separation distance of the adjacent inclined grooves 20 in the grinding wheel axis direction, The length of the groove 25 can be calculated so that it always passes through the grinding point from the pitch p of the inclined groove, the inclination angle α, and the width of the workpiece W to be ground. However, if the groove 25 is too long, the range of the grinding surface 15 on which the workpiece W is ground is reduced.

  Here, while effectively preventing dynamic pressure from being generated in the grinding fluid supplied to the grinding point P, it is possible to easily create the inclined groove 20 that can ensure high grinding accuracy and a long grinding wheel life. The conditions are as described below. The inclined groove 20 allows at least one, preferably two or more grinding points P to pass up and down within the width of the workpiece W, that is, the length in the axial direction of the grinding point P, regardless of the rotational phase of the grindstone 10. good. 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 end surface 21 of the abrasive layer 12, that is, the circumferential direction of the grindstone, and the length in the axial direction of the grinding point P 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. 6, and when the inclination angle α is increased by about 15 degrees, the groove circumferential width c decreases, and the superabrasive grains formed by the inclined groove 20 The spread of 16 intervals can be kept small.

  As shown in FIG. 7, 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, the two inclined grooves 20 are related to 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 up and down, the relationship between the inclination angle α and the number n of the inclined grooves 20 is shown in FIG. FIG. 9 shows the relationship between the pitch p of the inclined grooves 20 in the circumferential direction of the grindstone, and FIG. 10 shows the relationship between the inclination angle α and the reduction rate of the grinding surface 15 by the inclined grooves 20. As is apparent from FIG. 9, 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. 10, when the inclination angle α is smaller than about 15 degrees, the reduction rate of the area of the grinding surface 15 by the inclined grooves 20 can be reduced. As shown in FIG. 8, 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 plunge cut ground 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. In the example of the specifications of the inclined groove 20 determined so that the two inclined grooves 20 pass up and down the grinding point P, the groove width b is 1 mm, the groove depth h is 7 mm, the inclination angle α is 15 degrees, The number n is 39.

  Next, a method of manufacturing a grindstone with an inclined groove will be described with reference to FIG. As shown in FIG. 11A, the lower mold 42 is fitted to the inner bottom of the rectangular outer mold 41, and the arc-shaped 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 mold 42. The lower mold 42 is filled with the abrasive layer powder 44 in which the superabrasive grains 16 and the vitrified bond 17 constituting the abrasive layer 12 are mixed, so that the abrasive layer powder 44 has a uniform thickness. Leveled to be. In this state, as shown in FIG. 11 (b), the pressing die as the first upper die 45 is lowered along the inner surface of the outer die 41, and the abrasive layer powder 44 is temporarily pressed to remove the abrasive layer 12. Temporarily mold into an arc shape.

  Subsequently, as shown in FIG. 11C, 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 is increased. Is leveled to be uniform. In this state, as shown in FIG. 11 (d), the second upper mold 47 is lowered along the inner surface of the outer mold 41 and presses the ground layer powder 46 and the abrasive layer powder 44 simultaneously. . As a result, the base layer 13 is overlapped on the inner side of the abrasive grain layer 12 and integrally press-molded, whereby the arc-shaped grindstone tip 11 is formed. 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.

  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 inclined groove 20 is formed on the abrasive grain layer 12 of the grindstone chip 11 based on the above specifications. Are engraved on the outer peripheral grinding surface 15 of the grindstone 10 by machining or press molding with a grindstone.

  Next, the operation of the inclined grooved grindstone 10 of this embodiment will be described. The grindstone 10 is mounted on the grindstone base 32 supported by the grindstone base 31 of the grinding machine 30 shown in FIG. 2 by the core 14 and is driven to rotate, and the workpiece W is transferred to the work support device 33 including the headstock and the 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 pass at least one grinding point up and down regardless of the rotational phase rotation phase of the grindstone 10, the grinding fluid ( The coolant flows out upward and downward through the inclined groove 20, and the dynamic pressure generated at the contact portion between the grinding surface 15 and the surface of the workpiece W can be released from above and below the contact portion. 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. In addition, since the end of the inclined groove 20 is engraved up to the side end faces 21 and 22 parallel to the circumferential direction of the grindstone, both of the grindstone chips 11 and the side end faces 21 and 22 and the side wall face 23 of the inclined groove 20 are provided. , 24 can prevent cracking or chipping of the abrasive grain layer 12 due to grinding resistance without forming an acute angle that decreases the strength.

  Further, the distance between the adjacent inclined grooves 20 in the direction of the grindstone axis is determined by the grooves 25 formed between the adjacent inclined grooves 20 and in the center of the front end face 26 and the rear end face 27 parallel to the grindstone axis direction. Even when the workpiece W having a narrow grinding surface is ground, the dynamic pressure of the grinding fluid supplied to the grinding point P can be released by the grooves 25 extending in the circumferential direction of the grindstone.

  As an example of the grinding process, CBN abrasive grains having a particle size of # 120 are bonded by vitrified bond 17 with a concentration of 150 to form an abrasive grain layer 12, and an underlayer that does not contain superabrasive grains inside the abrasive grain layer 12 Normal direction 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, in which a grindstone tip 11 formed integrally with 13 is affixed to a steel core 14 Assuming that the grinding resistance and the profile accuracy of each are 100, the slope is obtained by engraving 39 inclined grooves 20 having a groove width b of 1 mm, a groove depth h of 7 mm, and an inclination angle α of 15 degrees on the outer peripheral grinding surface 15 of the grindstone. When the same cam was ground by the grooved grindstone 10, the grinding resistance in the normal direction was reduced to 77, and the profile accuracy was improved to 20 (see FIG. 12).

  In the above embodiment, the grindstone tip 11 is formed with the inclined groove main body 20a, the rear end portion 20a of the inclined groove, and the front end portion 20b of the inclined groove. As shown in FIG. 14, the rear half portion 20 e of the inclined groove 20 that is continuous with the front half portion 20 d of the inclined groove 20 formed in the grindstone chip 61 adjacent to the grindstone tip 61 in front of the grindstone in the rotation direction, and the grindstone tip 61. The front half 20d of the inclined groove 20 may be formed continuously to the rear half 20e of the inclined groove 20 formed in the grindstone chip 61 adjacent to the rear of the grindstone in the rotation direction.

  In addition, although at least one inclined groove passes above and below the grinding point, the present invention is not limited to this, and there may be a portion where the inclined groove does not pass in a part of the grinding surface of the grindstone.

  Moreover, about the groove | channel 25, when the front half part and the latter half part of the groove | channel 25 are each formed with the adjacent grindstone chip | tip, and a grindstone chip | tip is put in order and affixed on a core, the groove | channel 25 will be continuously formed in one groove | channel 25. However, the present invention is not limited to this, and as shown in FIGS. 13 and 14, between the adjacent inclined grooves 20 and between both end faces 21 and 22 parallel to the circumferential direction of the grindstone chip 61. You may provide in a center part. Moreover, as shown in FIG. 15, you may provide in any one of the front end surface 26 or the rear end surface 27 parallel to a grindstone axial direction.

The whole figure of the grindstone which consists of a segment type grindstone tip which shows an embodiment of the 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 | channel might pass a grinding point up and down. The figure which shows a grindstone chip. 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 up and down the grinding point which has the length of the same axial direction as the width of a workpiece. The graph which shows the relationship between the inclination angle of an inclination groove | channel, and a 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 process of manufacturing an inclined grooved grindstone. 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 figure which shows the grindstone with a sloping groove of other embodiment. The figure which shows the same grindstone chip. The figure which shows another example of a grindstone chip.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Whetstone, 11 ... Whetstone tip, 12 ... Abrasive layer, 13 ... Underlayer, 14 ... Core, 15 ... Grinding surface, 16 ... Superabrasive, 20 ... Inclined groove, 20a ... Inclined groove main body part, 20b ... After End part, 20c ... front end part, 20d ... front half part, 20e ... second half part, 21 ... side end face, 22 ... side end face, 23 ... side wall face, 24 ... side wall face, 25 ... groove, 26 ... front end face, 27 ... rear End face, 61 ... grinding wheel tip, P ... grinding point, W ... workpiece.

Claims (2)

A plurality of cores mounted on a grinding wheel shaft that is rotatably supported around the axis of the grinding wheel head of the grinding machine have an abrasive layer containing superabrasive grains and side end faces parallel to the circumferential direction of the grinding wheel. In the grindstone that grinds by grinding a work piece supported by a grinding support on a work support device of the grinding machine at a grinding point, with a grinding surface of
The grindstone tip is inclined with respect to the circumferential direction of the grindstone, and an inclined groove main body that occupies a main portion of the inclined groove , the end of which is engraved to the front side of each side of the grindstone chip ,
Continuing to the inclined groove main body formed in the grindstone tip adjacent to the grindstone tip in the forward direction of the grindstone, a rear end portion engraved to the front of one of the side end surfaces on both sides,
A front end portion engraved to the front of the other side end surface of the side end surfaces of the both sides, which is continuous with the inclined groove main body portion formed on the grindstone tip adjacent to the grindstone tip rearward in the rotation direction of the grindstone,
A whetstone with an inclined groove, characterized in that is formed . A plurality of cores mounted on a grinding wheel shaft that is rotatably supported around the axis of the grinding wheel head of the grinding machine have an abrasive layer containing superabrasive grains and side end faces parallel to the circumferential direction of the grinding wheel. In the grindstone that grinds by grinding a work piece supported by a grinding support on a work support device of the grinding machine at a grinding point, with a grinding surface of
The grindstone tip is inclined with respect to the grindstone circumferential direction, and an inclined groove in which an end is engraved to the front side of each side end surface of the grindstone tip ,
A groove formed between the adjacent inclined grooves and engraved so as to extend in the circumferential direction of the grindstone, at the center of at least one of the front end face and the rear end face parallel to the grindstone axial direction;
A whetstone with an inclined groove, characterized in that is formed.

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