JP2005288626A - Cutting grinding wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a segment tip having the periphery shape, managing with any disc-form base plate having different diameter, assuring good biting into a work to be cut even at the initial stage of cutting and having a good sharpness in cutting which lasts for a long time. <P>SOLUTION: The segment tip used upon fixing to the periphery of the base plate of a cutting grinding wheel has cutting surfaces and a fixing surface, the cutting surfaces having a base line and a protruding part, wherein the base line is a line not identical to one arc of a circle concentric to the circle part of which consists of an arc drawn by the fixing surface while the protruding part is located on the base line. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a segment tip of a cutting grindstone.

  For cutting stone, concrete, asphalt, etc., a cutting whetstone (saw blade), especially a diamond saw blade, in which segment chips are attached to the outer periphery of a disk-shaped substrate made of steel plate or stainless steel plate by means of brazing or the like is used. Yes.

  Conventionally, segment chips are generally molded and sintered as shown in FIG. That is, a predetermined metal powder and superabrasive grains are mixed, and the metal powder and superabrasive grains are mixed in a space 14 formed by each graphite mold including the upper punch 10, the lower punch 11, the spacer 12, and the holder 13. Put a thing, pressurize and heat in the direction of arrow C and fire. Accordingly, the shape of the bottom wall 15 of the upper punch 10 corresponds to the upper wall of the segment chip 17 (this portion corresponds to the outer periphery if it is assumed to be attached to a disk-shaped substrate), and the shape of the top wall 16 of the lower punch 11. Corresponds to the lower wall of the segment chip 17 (this portion corresponds to the inner periphery if it is assumed to be attached to a disk-shaped substrate).

  The diameter of the disk-shaped substrate varies depending on the object to be cut. The segment chip attached to the outer periphery of the disk-shaped substrate needs to correspond to the outer peripheral curve of the disk-shaped substrate having various diameters.

  Various improvements have been made with respect to the outer periphery of the segment chip, that is, the shape of the portion that is in direct contact with the object to be cut so that the sharpness is good and the good sharpness lasts for a long time with the minimum manufacturing cost.

  If the contact area with the work material at the beginning of cutting is large, the outer periphery of the segment tip loses its cutting resistance due to the force applied to the saw blade, and the so-called bite is not good and rattling occurs. Therefore, in order to improve the “biting” on the object to be cut from the beginning of cutting, the superabrasive grains are appropriately protruded by dressing, but such a process requires a large amount of grindstone and time. Therefore, it is desirable to minimize the process.

  Here, a description will be given regarding the optimum protrusion of superabrasive grains on the outer peripheral surface of the segment tip. Cutting to be cut is performed by superabrasive grains protruding on the outer peripheral surface of the segment chip, and the optimal protruding state for cutting differs depending on the work material. The optimum protruding state can be obtained when the segment tip is in contact with the object to be cut to some extent and the cutting proceeds. Since it takes time to shift to the projecting state adapted to the work material instead of the projecting state adapted to the work material at the initial stage of cutting, the cutting efficiency is inevitably poor at the initial stage. To create a protruding state of superabrasive grains suitable for the work material, it is necessary to wear the metal holding the superabrasive grains. For this reason, a protruding state of the superabrasive flow suitable for the work material is obtained. At the stage, a force is required separately from the cutting operation.

  In order to solve the problem of the initial cutting efficiency, there has been devised to reduce the cutting load by reducing the area where the segment tip contacts the work material at the initial stage of cutting (FIGS. 11 to 14). This also serves as a device for simplifying the dressing process. In the chip shown in FIG. 11 and the chip shown in FIG. 13, the area that needs to be dressed is large because the area of the portion that contacts the object to be cut is large. Further, in the chip shown in FIG. 12, since the area of the portion that comes into contact with the object to be cut is small, dressing is almost unnecessary, but there is a problem in that it costs much to cope with such a complicated shape. In addition, when the portion that comes into contact with the work material at the initial stage of cutting has an acute angle like the tip shown in FIG. 12, the impact at the first contact with the work material is large, and the “chip” at the tip of the segment tip is caused. The problem was that it was likely to occur.

  Further, the curvature of the outer peripheral surface curve of the segment chip corresponds to the diameter of the disk-shaped substrate (FIG. 8). For this reason, it is necessary to model the outer peripheries of various and complicated shapes shown in FIGS. 11 to 13 to correspond to the outer perimeter curve of the disk-shaped substrate. That is, in such a conventional segment chip, both the inner peripheral shape and the outer peripheral shape are various, so it is necessary to provide various upper punches and lower punches corresponding thereto, which is an economic problem, storage space Improvements have been sought due to problems with space and complicated product management.

  The chip shown in FIG. 14 has an advantage that the curvature of the outer peripheral surface curve of the chip does not need to correspond to the outer peripheral curve of the substrate. The shape shown in FIG. 14 has the same idea as the shape shown in FIG. 13, that is, a very large recess is provided at the center in the front-rear direction of the segment. By adopting such a shape, the area where the segment tip comes into contact with the work material when cutting is started can be greatly reduced. However, the chip shown in FIG. 14 has a problem that the longitudinal length of the chip cannot be made too long. That is, when the cutting operation is performed, contact with the cutting target starts only from the front corner portion and the rear corner portion of the chip, and after the cutting starts, the chip contacts the cutting target. The area is increasing. If the resistance becomes too large, the cutting ability is lowered, so that the length in the front-rear direction cannot be increased. Further, in order to obtain an effective superabrasive layer 20 (FIG. 15) having a certain height, the length of the segment chip in the front-rear direction cannot be made too long. When the length in the front-rear direction is short, it is necessary to attach a large number of chips to the substrate, and there is a problem in that it is complicated and the chips often come off.

  15 and 16, the relationship between the progress of cutting and the new cutting portion in the tip 25 (tip shown in FIG. 14) will be described in more detail, and the problems of the tip shown in FIG. 14 will be clarified. 15 and 16 are somewhat inaccurate for convenience of explanation. Reference numeral 20 denotes an effective superabrasive flow layer, reference numeral 21 denotes a virtual cutting surface, reference numeral 22 denotes a contact point between the virtual cutting surface and a portion where new cutting is performed, reference numeral 23 denotes a portion where new cutting is performed, and reference numeral 26 denotes The outer peripheral surface of the chip | tip 25 is each shown. As the cutting progresses, the virtual cut surface shifts in the order of 21a, 21b, and 21c, and the contact point with the part that performs the new cutting shifts in the order of 22a, 22b, and 22c. At that time, the angle I formed by the outer peripheral surface 26 of the chip and the virtual cut surface 21 decreases in the order of Ia, Ib, and Ic. As the angle I decreases, the volume of the part where new cutting is performed increases (FIG. 16). In proportion to the increase in the volume of the part where new cutting is performed, the amount that must be cut to make the superabrasive grains protrude is increased. The cutting resistance increases in proportion to this increase. Therefore, in order to maintain the sharpness, it is necessary to form the concave portion with an inclined surface having a large angle as much as possible. However, if this is done, the depth of the concave portion becomes deep and the effective superabrasive grain layer 20 is reduced. For this reason, in order to obtain an inclined surface having a large angle as much as possible while securing a practical effective superabrasive layer, the length in the front-rear direction of the chip must be shortened.

  In addition, the angle I approaches 0 degrees due to the progress of wear of the chip, and the time when the concave portion disappears is 0 degree. However, the cutting resistance increases with the increase of the portion where the new superabrasive flow protrudes, and the concave portion disappears. To the maximum. At the same time, the area where the segment tip comes into contact with the work piece is also maximized, and the tip 25 may cause a reduction in sharpness at this time.

JP 2003-200416 A JP-A-10-58329 Japanese Utility Model Publication No. 61-35742

  An object of the present invention is to provide a segment chip that can be used for any of various disk-shaped substrates, that is, a versatile segment chip, with respect to the shape of the outer periphery of the segment chip.

  In addition, segment chips that have minimum manufacturing costs, are easy to manufacture, have good sharpness, and have good sharpness for a long time, or segment chips that have good “biting” from the beginning of cutting or do not require dressing. It is an object to provide a simple segment chip.

  The front of the segment refers to the direction in which the segment precedes when the substrate rotates, and the rear of the segment refers to the opposite side of the front.

  The segment chip according to the present invention can be applied to any of the disk-shaped substrates having various diameters with respect to the outer peripheral shape thereof, that is, has versatility.

  In addition, the segment chip of the present invention has a good sharpness and a good sharpness for a long time with a minimum manufacturing cost.

  In addition, the segment chip of the present invention has good “biting” to the cutting object from the beginning of cutting. Further, in the segment chip of the present invention, such a good bite can be obtained without a dressing process.

  Further, the segment chip of the present invention can have a certain length in the longitudinal direction.

  The invention according to claim 1 is a segment chip that is used by being fixed to an outer periphery of a substrate of a cutting grindstone, having a cut surface and a fixed surface, the cut surface having a base line and a protrusion, and the base line being the The problem is solved by a segment chip that is a line that does not coincide with a circular arc that is concentric with a circle that is part of an arc drawn by the fixing surface, and in which the protrusion is disposed on the base line.

  The basic configuration of the cutting grindstone is as before. That is, it is configured by a substrate made of a disk shape, a steel plate or the like, and a segment chip that is brazed to the outer periphery of the substrate and fixed by welding or the like. The segment chip is formed by sintering superabrasive grains such as diamond and various metal powders mixed at a predetermined ratio. Cutting is performed when the substrate rotates and the object to be cut comes into contact with the segment chip. That is, the segment chip has a fixing surface that is fixed to the substrate and a cutting surface that is located on the outermost periphery of the cutting grindstone when fixed to the substrate. As a result of the cutting, the segment tip is worn away and becomes nonfunctional. When it stops functioning, a new segment chip can be fixed to the substrate and reused as a new cutting wheel.

  The feature of the present application is the shape of the cut surface. The cut surface of the segment chip according to the present application includes a base line and a protrusion. The base line is a portion other than the protrusion. The protrusion is a portion protruding from the base line. Even in the conventional segment chip, the cut surface is composed of a base line and a protrusion. However, the conventional base line of most segment tips is a line that coincides with one arc of a circle concentric with a circle that is part of the arc drawn by the fixing surface. Here, since the circle having a part of the arc drawn by the fixing surface is a circle concentric with the center of rotation of the substrate, the base line is also a circle concentric with the center of rotation of the substrate when the segment chip is attached to the substrate. It coincided with one arc. Therefore, the base line needs to be an arc corresponding to the size of the substrate. For this reason, even when a chip with a cut surface having the same shape (the same shape in terms of the size, shape and arrangement of the protrusions) is obtained, a plurality of upper punches are prepared corresponding to the size of the substrate in the manufacturing process. This has led to complicated and economical burden of product management. However, in the segment chip according to the present application, the base line does not need to coincide with the arc of the concentric circle. As a result, it is not necessary to use a baseline corresponding to the size of the substrate, and only one type of upper punch is used in the manufacturing process as long as it has the same shape (the same shape in terms of the size, shape and arrangement of the protrusions). It is sufficient if it is provided, and the problems such as the complicated and economical burden of product management are solved.

  Some conventional segment chips do not coincide with one arc of a circle concentric with a circle whose part is an arc drawn by the fixing surface (FIG. 14). However, this also has a problem that the length in the front-rear direction is limited as described above. This problem is solved by the tip according to the present application, in which the cut surface of the tip is provided with a protrusion in addition to the base line.

  As a result, a chip having a long longitudinal length can be obtained. Further, by providing such a protrusion, the cooling water used for cutting flows into the cut surface along the curve of the protrusion, and as a result, water can be sufficiently supplied to the cut surface, resulting in sufficient cooling. There is also an advantage that the sharpness is improved.

  The invention according to claim 2 solves the problem by the segment chip according to claim 1, wherein the base line is a straight line.

  Although the base line and the work material come into contact with each other when the protrusion is worn out and disappears, it is possible to prevent the contact area from rapidly increasing by configuring the base line with a straight line. The portion where the superabrasive grains do not protrude comes into contact with the work material only in small amounts, and less force is required to project the superabrasive grains. When the base line has an arc shape, a large number of base line portions come into contact with the work material at the same time as the protrusion disappears, causing a sudden increase in load and causing problems such as defective cutting.

  The invention according to claim 3 solves the problem by the segment chip according to claim 1, wherein the base line is a tangent line of a circle concentric with a circle whose part is an arc drawn by the fixing surface. To do.

  By making the base line the tangent of a circle concentric with the center of rotation of the substrate, the base line and the work material come into contact when the protrusion wears out and disappears. From this, vibration can be suppressed and a smooth transition to the main cutting is possible. In addition, the structure of the upper punch used in the manufacturing process can be simplified, and the economic burden can be suppressed.

  According to a fourth aspect of the present invention, in the thickness direction of the segment tip, the projecting portion is in the center of the circumferential length of a circle concentric with a circle having a part of an arc drawn by the fixing surface of the segment tip. The problem is solved by the segment chip according to claim 1, characterized in that the line extends symmetrically with respect to the axis.

  By making it bilaterally symmetric, manufacturing is greatly facilitated. That is, when sintering, the mold can be inserted without considering the left and right direction.

  According to a fifth aspect of the present invention, there is a problem with the segment tip according to the first aspect, wherein the shape of the protrusion is an arc, and the diameter of a circle having a part of the arc is 20 mm or less. To solve.

  By making the shape of the protrusion into an arc, at the time of cutting, the object to be cut and the cut surface are always in contact with each other at substantially “points”. For this reason, dressing can be made unnecessary. Moreover, it has been found from experiments that the arc is most effective when the diameter is 20 mm or less.

  If the shape of the protrusion is, for example, a triangle, its apex is weak in strength, causing damage rather than wear of the protrusion, and cannot contribute to cutting. Further, for example, in the case of a quadrangular shape, if the flat portion at the apex (segment outer peripheral portion) is widened, the contact area with the work material becomes wide and dressing is required. Moreover, if dressing is made narrower than necessary, the shape becomes substantially triangular, resulting in insufficient strength.

  The invention according to claim 6 solves the problem by the segment chip according to claim 5, wherein there are two or more protrusion heights of the protrusion.

  When the protrusions have the same protrusion height, the protrusions sequentially contact the work material from both ends toward the center. In this case, when viewed with the entire rotating grindstone, the contact interval with the work material becomes uneven. By making it two types and making both ends and the central part the same height and lowering the height of the protrusion between the center and both ends, both ends first contact with the work material, then the central part contacts, Projections between both ends and the center come into contact with each other. By controlling the order of contact in this way, the contact interval between the protrusions can be made more even. That is, vibration can be suppressed by making contact vibration with the work material finer, and crushing or falling off of superabrasive grains due to vibration can be suppressed, thereby improving machinability.

  According to the seventh aspect of the present invention, the position of the action site newly generated as the cutting progresses when being fixed to the cutting grindstone and used for cutting is the center of the segment chip in the rotational direction from the front and rear of the segment chip. The problem is solved by the segment chip according to claim 1, which is made to appear sequentially toward.

  The invention according to claim 8 is the segment tip according to claim 1, wherein all of the cut surfaces become the action site immediately after the center of the length in the rotation direction of the segment tip becomes a new action site. Solve the problem.

  The best mode is shown by Examples 1 to 3.

  Example 1 is shown in FIG.1 and FIG.2. A segment chip 2 according to the first embodiment is attached to the outer periphery of the disk-shaped substrate 1. The outer periphery 3 of the segment chip 2 does not follow the arc drawn by the concentric circles of the disk-shaped substrate. The outer periphery 3 of the segment chip 2 is along a straight line parallel to the tangent line at the midpoint M between the ends 6a and 6b of the segment chip mounting portion of the disc-like substrate 1.

  Thus, by making the outer periphery of the segment chip 2 substantially straight, the shape of the outer periphery can be adapted to a disk-shaped substrate having various diameters, and the upper punch 10 required for sintering (FIG. 3). Can be used universally.

  As shown in FIG. 2, the rotation direction of the diamond saw blade is the direction of the arrow R, and at the initial stage of the cutting operation, the two locations of the end 7a and the end 7b of the segment tip 2 are in contact with the work material. As the work material is cut, the contact area is gradually increased. As a result, the transition from the protruding form of the superabrasive grains in the dressing state to the protruding form of the superabrasive grains suitable for the work material and cutting conditions occurs promptly. 8 shows the protrusion part of the superabrasive grain formed in the segment chip | tip by dressing. Reference numeral 4 denotes a virtual line where the work of the segment tip advances and the segment tip 2 comes into contact. When the wear progresses to the imaginary line 4, the segment tip comes into contact with the work material at the portions A1, A2, B1, and B2, but the portions A1 and B1 are obtained by cutting the work material already. The portion where the transition to the protruding state of the superabrasive grains suitable for the work material has been completed is made, and the portions A2 and B2 become the portions being transferred. The contact area of A2 and B2 is very small compared to a general diamond blade, and it is possible to quickly shift to a protruding state of superabrasive grains that are optimal for main cutting.

  Example 2 is shown in FIG. In Example 2, it forms with the front-end | tip arc of the part which contacts a work material first. When the end portion has an acute angle, the impact is increased when it first comes into contact with the work material, and the chip of the segment tip may occur. This is a measure for preventing this.

  A third embodiment is shown in FIGS. 5, 6, 7, 8, and 9. In the third embodiment, a substantially arc-shaped protrusion is provided on the outer periphery of the segment chip formed by a substantially straight line. As the wear of the segment progresses, the areas of A1 and B1 in FIG. 2 increase and the contact area with the work material increases. As the contact area increases, the wear speed of the segment tip decreases, and the transition speed of the superabrasive grains optimal for the main cutting to the protruding state also decreases. Further, as the outer diameter of the diamond blade increases, the circumferential length L of the segment tip increases, and the areas of A2 and B2 in FIG. 2 increase correspondingly. As the area increases, the transition speed for shifting to the protruding state of superabrasive grains optimal for the main cutting becomes slower.

  That is, by making the outer peripheral surface a relatively small protrusion on the reference surface, it is possible to control the contact point between the work material and the segment tip. This mechanism will be described with reference to FIG. In FIG. 8, the protrusions have the same shape. In this case, the order in which the protrusions (b) (c) (d) (e) (f) (f) contact the work material is (b) (g) first, then (c) (c) F) comes into contact, and (d) (e) comes into contact at the end. As shown in FIG. 9, when the first contact is made with the protrusion (reference numeral 18), the amount that must be scraped to make the superabrasive particles protrude is maximized, but wears quickly and against the virtual cutting line. The angle between the tangent line of the virtual cutting line (same as the outer periphery of the cutting wheel) and the line passing through the contact point must be sharpened so that the superabrasive grain must protrude. The amount decreases. Since the contact between the protrusions and the workpiece always occurs at different positions on each protrusion, the amount that must be cut to make the superabrasive grains protrude does not increase proportionally and does not exceed a certain value. Transition. Therefore, the sharpness does not deteriorate due to an increase in the amount that must be cut to make the superabrasive grains protrude.

  As the area where the segment tip contacts the work material increases, the cutting load also increases. In the case of the segment structure of FIG. 14 which is the prior art, both the area in contact with the work material and the amount that must be cut in order to make the superabrasive grains protrude are both increasing, and cutting addition is simultaneously maximized. It may cause a decrease in sharpness. However, in Example 3, the amount that must be cut in order to make the superabrasive grains protrude at a position where the segment tip contacts the work material is almost reduced, and the sharpness decreases due to an increase in cutting load. No.

  Further, according to Example 3, even when the length of the segment tip in the front-rear direction is increased, the contact between the protrusion and the work material always occurs at a different position of each protrusion. The amount that must be shaved to make it protrude does not exceed a certain value. For this reason, the length of the segment chip in the front-rear direction can be increased. Since the protrusion is relatively small, a sufficient effective abrasive layer 20 (not shown, similar to 20 in FIG. 15) can be secured. Moreover, since the size of the protrusion is not related to the length of the segment tip in the front-rear direction, a sufficient abrasive layer can be secured even if the length of the segment tip in the front-rear direction is increased.

  By providing the substantially arc-shaped protrusions shown in the third embodiment, the area in contact with the work material at the initial stage can be further reduced regardless of the circumferential length L of the segment tip or the outer diameter of the diamond blade. . There are only two points that come into contact with the work material in the initial stage for each segment chip, and the rotational torque of the diamond blade necessary for the initial cutting can be greatly reduced, and good initial machinability is ensured. Since the initial contact with the work material is only two points for each segment, the impact on the protrusion is increased, but by making the protrusion shape substantially arc-shaped, the protrusion of the protrusion due to the impact during initial cutting is increased. Breakage can be prevented.

  When the protrusion wears out and disappears, the base line contacts the work material. In Example 3, since the base line does not correspond to the curve corresponding to the diameter of the disk-shaped substrate, the contact area does not increase rapidly when reaching the effective abrasive layer.

  According to the configuration of Example 3, the portion where the superabrasive grains do not protrude comes into contact with the work material only in small amounts, and less force is required to project the superabrasive grains. . When the base line has an arc shape, many base line parts come into contact with the work material at the same time as the protrusion disappears, and the base part where many superabrasive grains do not protrude comes into contact with the work material and suddenly changes. This increases the load and causes problems such as cutting defects.

  The present invention can be used for a segment tip of a cutting grindstone. The objects to be cut are stone, concrete, asphalt and the like. Superabrasive grains include everything including diamond.

The state which fixed the segment chip concerning Example 1 of the present invention to a substrate is shown. It is a figure which shows the relationship of the contact area of the segment chip | tip and work material concerning this invention. It is a figure which shows the manufacturing process of a segment chip | tip. It is a figure which shows Example 2 of this invention. It is a figure which shows Example 3 of this invention. It is a figure which shows Example 3 of this invention. It is a figure which shows Example 3 of this invention. It is a figure which shows the relationship of the contact area of the segment chip | tip and work material concerning Example 3 of this invention. It is a figure which shows the relationship of the contact area of the segment chip | tip and work material concerning Example 3 of this invention. The state which fixed the conventional segment chip | tip on the board | substrate is shown. It is a figure which shows the conventional segment chip | tip. It is a figure which shows the conventional segment chip | tip. It is a figure which shows the conventional segment chip | tip. It is a figure which shows the conventional segment chip | tip. It is a figure which shows the relationship between the contact area of the conventional segment tip and a workpiece. It is a figure which shows the relationship between the contact area of the conventional segment tip and a workpiece.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Disc-shaped board | substrate 2 Segment chip | tip 3 Outer periphery 4 Circular arc 6 End of adhesion surface 7 End of outer peripheral surface 8 Projection part 10 Upper punch 11 Lower punch 12 Spacer 13 Holder 14 Space 15 Bottom wall 16 Top wall 17 Segment chip 20 Effective superabrasive layer 21 Virtual cutting surface 22 Contact 23 New cutting portion 25 Segment chip

Claims (8)

A segment chip that is used by being fixed to the outer periphery of a substrate of a cutting grindstone, having a cut surface and a fixed surface, wherein the cut surface is composed of a base line and a protrusion, and the base line is attached to the segment chip on the substrate The segment chip is formed of a line that does not coincide with a circular arc concentric with the rotation center of the substrate, and the protrusion is disposed on the base line. The segment chip according to claim 1, wherein the base line is a straight line. The segment chip according to claim 1, wherein the base line is a tangent of a circle concentric with the center of rotation of the substrate when the segment chip is attached to the substrate. The protrusion is symmetrical with respect to a line extending in the thickness direction of the segment tip at the center of the circumferential length of a circle concentric with a circle having a part of an arc drawn by the fixing surface of the segment tip. The segment chip according to claim 1, wherein the segment chip is provided. The segment chip according to claim 1, wherein the shape of the protrusion is an arc, and the diameter of a circle having the arc as a part thereof is 20 mm or less. The segment chip according to claim 5, wherein there are two or more protrusion heights of the protrusions. The position of the action part newly generated as the cutting progresses when it is fixed to the cutting grindstone and used for cutting is made to appear sequentially from the front and rear of the segment tip toward the center of the segment tip in the rotational direction. The segment chip according to claim 1. 2. The segment chip according to claim 1, wherein all of the cut surfaces become the action parts immediately after the center of the length in the rotation direction of the segment chip becomes a new action part.

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