JP2007245288A - Method for dressing superabrasive grinding wheel and device to be used in the same method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further enhance grinding accuracy and to further improve productivity of grinding by further improving a dressing effect, while suppressing wear of a grinding wheel as much as possible. <P>SOLUTION: A grinding using surface 5a of a superabrasive grinding wheel 5 is dressed by a rotary dresser 6 imparted with a cut and performed with a feed operation by changing peripheral speed Vd of the rotary dresser 6 by adopting at least two of a first dressing process in which the peripheral speed Vd of the rotary dresser 6 is set to be smaller than peripheral speed Vw of the superabrasive grinding wheel 5, a second dressing process in which the peripheral speed Vd is set to be the same as the peripheral speed Vw, and a third dressing process in which the peripheral speed Vd is set to be larger than the peripheral speed Vw. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dressing method of a superabrasive grindstone for grinding a workpiece (work) such as a difficult-to-cut material and a technical field of an apparatus used for the method.

  There are some difficult-to-cut materials that are difficult to grind due to the unique properties of the material to be ground. As a grindstone for grinding this difficult-to-cut material, a superabrasive grindstone (called a grinding wheel in JIS 4131) made of diamond or cubic boron nitride (CBN) has been conventionally used.

  In this grinding wheel, the cutting edge gradually changes as the grinding process continues. However, if the change of the cutting edge increases, the abrasive grains may become clogged (worn, worn) or clogged (chips will adhere). And welding) will occur. When such clogging or clogging occurs, grinding burn occurs on the workpiece, chattering occurs, and further, abrasive grains are deteriorated due to deterioration of the bonding material (bond) of the grinding wheel due to heat generation during grinding. The holding force may decrease and normal grinding may not be possible.

  Therefore, conventionally, truing and dressing of a diamond or CBN grinding wheel is performed to regenerate the bluntly changed cutting edge of the grinding wheel into a sharp cutting edge. Truing is “reshaping” that adjusts the outer periphery of the grinding wheel into a correct shape, and “dressing” is “sharpening” that gives a sharp cutting edge to the outer peripheral surface of the grinding wheel (see, for example, Non-Patent Document 1).

  In this Non-Patent Document 1, a rotary truing tool is cut in a predetermined amount with respect to a grinding wheel and rotated in the same direction as the grinding wheel or in the opposite direction to the grinding wheel in a direction parallel to the rotational axis of the grinding wheel. Traversing and truing the outer peripheral surface of the grinding wheel, with the rotary dresser cut into the grinding wheel by a predetermined amount, in the same direction as the rotation direction of the grinding wheel (the dressing part where the rotary dresser and the grinding wheel make contact) The direction of both peripheral speeds in the reverse direction: generally called up cut or up dress) or the reverse direction (the direction of both peripheral speeds in the dressing part where the rotary dresser contacts the grinding wheel is the same direction: generally , Called down cut or down dress), and the peripheral speed of the grinding wheel Dressing the grinding use surface on the outer periphery of the grinding wheel at a circumferential speed ratio of a circumferential speed ratio between the value of 1 and the absolute value of the rotary dresser of 1, a circumferential speed ratio greater than 1, and a circumferential speed ratio less than 1 Is disclosed.

By the way, truing and dressing disclosed in this Non-Patent Document 1, and in general, truing and dressing of a grinding wheel are conventionally performed by grinding a grinding object with a grinding wheel when the grinding wheel is clogged or clogged. This is performed in an interrupted manner or when the workpiece is not ground by the grinding wheel.
However, when the object to be ground is not ground in this way, providing a dedicated truing process and dressing process is inefficient and takes a lot of grinding time.

  Therefore, during the grinding stroke of the workpiece to be ground by the grinding wheel, the dressing of the grinding wheel is continuously performed, and at the same time, the cutting of the rotary dresser to the grinding wheel is corrected to correct the cutting of the grinding wheel to the workpiece. There has been disclosed a continuous dressing method for a grinding wheel that eliminates the need for an independent dressing time by continuously performing computer numerical control (see, for example, Non-Patent Document 2).

According to this continuous dressing method, the sharpness of the superabrasive grinding wheel is always maintained well even when difficult-to-cut materials are to be ground, so that the table creep feed under deep cutting conditions can be speeded up. Grinding wheel selection (soft coupling degree, air holes) giving priority to improving sharpness and preventing clogging of the grinding wheel has good shape accuracy of the grinding wheel. In precision grinding, the grinding start point and grinding end point of the workpiece Effects such as no difference in processing accuracy and improvement in productivity can be obtained.
Dekaban Skills Books 7 Grinding Machine Utilization Manual, Editing Tool Engineer Editorial Department, 3rd Edition, published on June 5, 2001, published by Okawa Publishing Co., Ltd. 78-83 “Rotary dresser for high-precision and high-efficiency grinding”, 84-89 “Cruising and dressing of CBN grinding wheels”]. Challenge to super production processing technology, editor Advanced processing technology study group, first edition, published on November 25, 1984, published by Industrial Research Co., Ltd. 2 Key items of creep feed grinding technology: 8 Creep feed grinding machines ”].

  However, although the continuous dressing method disclosed in Non-Patent Document 2 can obtain the above-described effect, the grinding wheel is dressed at a single peripheral speed ratio between the peripheral speed of the grinding wheel and the peripheral speed of the rotary dresser. Therefore, it cannot be said that dressing is performed efficiently and effectively. For this reason, the wear of the grinding wheel is increased accordingly, and there is room for improvement in the dressing effect.

  The present invention has been made in view of such circumstances, and its purpose is to further improve the dressing effect while suppressing wear of the grinding wheel as much as possible, to further improve the grinding accuracy and to improve the grinding process. It is an object to provide a dressing method for a superabrasive grindstone that can further improve productivity and an apparatus used in this method.

  In order to solve the above-described problem, the dressing method of the superabrasive grindstone according to the first aspect of the present invention is the rotation of the superabrasive grindstone in the dressing section while cutting the rotary dresser into the superabrasive grindstone. Dressing the superabrasive grindstone by rotating it so that the peripheral speed is the same as the peripheral speed and reciprocating in the feed direction parallel to the rotation axis of the superabrasive grindstone In the method, a first dressing step of dressing the superabrasive grindstone by setting a peripheral speed of the rotary dresser smaller than a peripheral speed of the superabrasive grindstone, and a peripheral speed of the rotary dresser of the superabrasive grindstone A second dressing step for dressing the superabrasive grindstone at the same setting as the peripheral speed, and the peripheral speed of the rotary dresser is set larger than the peripheral speed of the superabrasive grindstone. And a third dressing step for dressing the superabrasive grindstone, wherein the rotary dresser dresses the superabrasive grindstone by at least two dressing steps among the first to third dressing steps. It is said.

  Further, the dressing method of the superabrasive grindstone of the invention of claim 2 is the same direction as the direction of the peripheral speed of rotation of the superabrasive grindstone in the dressing portion while giving a cut to the superabrasive grindstone. In the dressing method of a superabrasive grindstone for dressing the superabrasive grindstone by rotating it so that the peripheral speed is equal to and a reciprocating movement in a feed direction parallel to the rotation axis of the superabrasive grindstone, A first dressing step for dressing the superabrasive grindstone by setting a peripheral speed smaller than the peripheral speed of the superabrasive grindstone, and a peripheral speed of the rotary dresser is set equal to the peripheral speed of the superabrasive grindstone. A second dressing step for dressing the superabrasive grindstone, and setting the peripheral speed of the rotary dresser to be larger than the peripheral speed of the superabrasive grindstone, And a third dressing step of Lessing, the rotary dresser, is characterized by dressing the superabrasive grinding wheel by at least the last to the first dressing step.

Further, in the dressing method for a superabrasive grindstone according to the invention of claim 3, each dressing step during the reciprocating motion of the rotary dresser is continuously performed for a set number of times set in each step, or the rotary dresser is performed. Each of the dressing processes during the reciprocating motion is intermittently repeated a set number of times set in each process.
Furthermore, the dressing method of the superabrasive grindstone of the invention of claim 4 is characterized in that the moving speed at the time of forward movement and the moving speed at the time of backward movement of the rotary dresser are changed.

  Furthermore, the dressing apparatus for a superabrasive grindstone of the invention of claim 5 is a dressing apparatus for a superabrasive grindstone used in the dressing method for a superabrasive grindstone according to claim 3 or 4, wherein the rotary dresser is Rotation driving means for rotating the dressing part so that the peripheral speed is the same as the peripheral speed of the abrasive grindstone, and a cutting means for moving the rotary dresser in the cutting direction with respect to the superabrasive grindstone, The rotary dresser comprises a feed means for reciprocating the rotary dresser in the feed direction with respect to the superabrasive grindstone, and a control device for controlling the rotation drive means, the cutting means, and the feed means. The rotary dresser has respective peripheral speeds when performing at least two dressing steps among the first to third dressing steps. A control device for controlling the rotation driving means or the rotation driving means so as to have respective peripheral speeds when the rotary dresser performs at least two dressing steps among the first to third dressing steps. It is a control device for controlling the feeding means so that the feed movement speed of the rotary dresser changes between forward movement and backward movement.

  According to the dressing method of the superabrasive grindstone of the invention of claims 1 to 4 and the superabrasive grindstone dressing apparatus of claim 5 configured as described above, the peripheral speed of the rotary dresser is set to the peripheral speed of the superabrasive grindstone. The first dressing step for dressing with a smaller setting, the second dressing step for dressing with the peripheral speed of the rotary dresser set equal to the peripheral speed of the superabrasive grindstone, and the peripheral speed of the rotary dresser being superabrasive The peripheral speed between the peripheral speed of the superabrasive wheel and the peripheral speed of the rotary dresser during the dressing process is performed by performing at least two dressing steps including a third dressing step for performing dressing by setting the peripheral speed higher than the peripheral speed of the grain grindstone. Since the superabrasive grindstone is dressed by changing the ratio, the dressing can be performed more efficiently.

  Therefore, it is possible to efficiently purify (clean) foreign matters such as chips adhering to the superabrasive grindstone. Further, the wear of the superabrasive grindstone can be reduced to prevent clogging and clogging of the superabrasive grindstone, and the superabrasive grindstone can be sharply and satisfactorily performed. As a result, the sharpness of the superabrasive grindstone is sharpened to eliminate chatter when grinding the workpiece with the superabrasive grindstone, enabling stable grinding with good sharpness and improving the dressing effect. Can do. As a result, the grinding accuracy can be further improved, the productivity of grinding can be further improved, and the cost for grinding can be reduced.

  In addition, by continuously performing at least two dressing steps among the first to third dressing steps having different peripheral speeds of the rotary dresser, the grinding use surface of the superabrasive grindstone can be efficiently dressed. The planarization of the cylindrical surface (outer peripheral surface) and the equalization of the dressing of the superabrasive grindstone can be achieved more effectively.

  In addition, the second abrasive dressing step in which the peripheral speed of the rotary dresser and the peripheral speed of the superabrasive grindstone are set to be the same in the at least two dressing steps described above, thereby holding the superabrasive grindstone. An appropriate amount of the material can be removed, and the superabrasive particles that have been worn or worn can be efficiently removed, and new superabrasive grains can be grown spontaneously. Therefore, the wear of the superabrasive grindstone can be further reduced, the occurrence of clogging and clogging in the superabrasive grindstone can be further suppressed, and the sharpening of the superabrasive grindstone can be performed more reliably and satisfactorily.

  In particular, according to the dressing method for a superabrasive grindstone according to the invention of claim 2, in addition to the above-mentioned effects, the abrasive having a cutting edge that is ineffective for cutting in the second dressing step as described above is a superabrasive grindstone. Abrasive grains that have a cutting edge effective for cutting and that remain on the superabrasive grindstone are removed by the first dressing step, and the front surface of the abrasive grains that greatly affects the sharpness of the superabrasive grindstone is effective. Therefore, the sharpness of the superabrasive grindstone can be improved.

  Furthermore, among the difficult-to-cut materials that are the materials to be ground, especially when high-hardness diamond is ground with a superabrasive grindstone made of diamond, as described above, when rotating the material to be ground with the superabrasive grindstone, rotary Since the superabrasive grindstone is effectively dressed by changing the peripheral speed of the dresser and performing the dressing of the superabrasive grindstone, the wear of the expensive diamond of the superabrasive grindstone can be reduced. Therefore, the sharpness of the superabrasive grindstone can be maintained well and stably for a long time, and diamond can be always ground with high efficiency. This facilitates the production of diamond by grinding, further improves productivity and further reduces the cost of grinding.

  Furthermore, since the super-abrasive grindstone can be dressed by the rotary dresser during the grinding of the workpiece by the super-abrasive grindstone, in the grinding process for difficult-to-cut materials disclosed in Non-Patent Document 2 described above. An effect can also be obtained.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view schematically and schematically showing an example of a square surface grinder to which an example of an embodiment of a dressing apparatus for a superabrasive grindstone according to the present invention is applied.

  As shown in FIG. 1, a rectangular surface grinder 1 of this example is an X-axis direction moving table provided on a main body 2 so as to be able to reciprocate in the left-right direction (X-axis direction) in the same manner as a known square surface grinder. 3, a Z-axis direction moving table 4 provided on the X-axis direction moving table 3 so as to be able to reciprocate in the front-rear direction (Z-axis direction), and a workpiece (workpiece) W is set on the X-axis direction moving table 3. A superabrasive grindstone (grinding wheel) 5 that is provided so as to be rotatable via the axis A and is reciprocated in the vertical direction (Y-axis direction) on the main body 2 to grind the workpiece W. It is provided so as to be rotatable via a dresser rotation axis B, and can reciprocate in the body 2 in both the vertical direction (Y axis direction) and the dresser rotation axis B (parallel to the grinding wheel rotation axis A) direction (Z axis direction). The grinding use surface 5a of the superabrasive grindstone 5 is provided. And a dressing apparatus 7 having a rotary dresser 6 to Lessing.

  The superabrasive grindstone 5 is rotated via a grindstone rotation axis A by a rotation driving servomotor (not shown), and is also moved by a Y-axis direction moving servomotor (not shown) and a feed screw mechanism (not shown). It is linearly moved in the Y-axis direction (the cutting direction of grinding with respect to the workpiece W and its opposite direction).

By the way, there exists what consists of a difficult-to-cut material in the workpiece W. This difficult-to-cut material has the following properties as described in Patent Document 2 described above.
(A) The elongation of the material is large.
(B) Chips are likely to be welded to the grinding wheel surface during grinding.
(C) poor thermal conductivity,
(D) work hardening by grinding heat;
(E) The material is hard and strong.

  Therefore, in the square surface grinding machine 1 of this example, the superabrasive grindstone 5 is configured as a grinding wheel formed from diamond or CBN in order to enable grinding of such difficult-to-cut materials. Without being limited thereto, the superabrasive grindstone 5 can also be configured as a grindstone for grinding an object W to be ground other than a difficult-to-cut material.

The rotary dresser 6 is rotated via a dresser rotating shaft B by a rotating servo motor (not shown; corresponding to the rotation driving means of the present invention), and also a pulse motor (not shown; Servo motor for moving in the Y-axis direction (dressing cutting direction with respect to the superabrasive grindstone 5 and vice versa) and in the Z-axis direction by a feed screw mechanism (not shown) and a feed screw mechanism (not shown). It is linearly moved in the Z-axis direction (the dresser rotation axis B direction; that is, the direction parallel to the grindstone rotation axis A) by a feed dressing mechanism (not shown) and a feed screw mechanism (not shown). In this example, the rotary dresser 6 is set to the same width as that of the superabrasive grindstone 5 and is formed of a GC abrasive grain or a WA abrasive grindstone with a JIS abrasive symbol. The GC abrasive grains are high-purity silicon carbide (SiC) abrasive grains, and the WA abrasive grains are high-purity alumina (Al ₂ O ₃ ) abrasive grains. Needless to say, the width of the rotary dresser 6 and the width of the superabrasive grindstone 5 may be different from each other.

  Each drive of each servo motor and pulse motor described above is numerically controlled by a control device (computer) (not shown) as in the prior art, and even during grinding of the workpiece W of the superabrasive grindstone 5. The dressing of the superabrasive grindstone 5 by the rotary dresser 6 is performed.

Next, a dressing method of the superabrasive grindstone 5 by the rotary dresser 6 in the dressing apparatus of this example will be described.
As shown in FIG. 2, the dressing method for the superabrasive grindstone 5 in this example is such that the rotary dresser 6 is rotated in the direction opposite to the rotational direction of the superabrasive grindstone 5, that is, the rotary dresser 6. The rotary dresser 6 is rotated so that the direction of the peripheral speed Vd of the rotary dresser 6 is the same as the direction of the peripheral speed Vw in the rotation of the superabrasive grindstone 5 in the dressing portion α where the superabrasive grindstone 5 contacts. (Down cut or down dress). In addition, the rotary dresser 6 is moved by a small amount downward in the Y-axis direction (downward in FIG. 2) toward the superabrasive grindstone 5, so that a predetermined minute cut of the rotary dresser 6 with respect to the superabrasive grindstone 5 is set. Is done. At this time, when the dressing of the superabrasive grindstone 5 is continuously performed during the execution of the grinding stroke of the workpiece W by the superabrasive grindstone 5, the cut amount of the superabrasive grindstone 5 to the workpiece W is corrected. In order to achieve this, the rotary dresser 6 is continuously cut into the superabrasive grindstone 5 by computer numerical control.

  In this way, the rotary dresser 6 is rotated while being given a predetermined small amount of cut, and the rotary dresser 6 is in the feed direction (Z-axis direction; left and right direction in FIG. The grinding use surface 5a of the abrasive grindstone 5 is dressed by reciprocating in the width direction (thickness direction).

  In the dressing method for the abrasive grindstone 5 in this example, the peripheral speed Vw of the superabrasive grindstone 5 is controlled to be constant, and the peripheral speed Vd of the rotary dresser 6 is next to the peripheral speed Vw of the superabrasive grindstone 5. The first to third dressing processes controlled to three different peripheral speeds are set. That is,

(1) First Dressing Step As shown in FIG. 2A, in this first dressing step, the peripheral speed Vd of the rotary dresser 6 in the dressing portion α is smaller than the peripheral speed Vw of the superabrasive grindstone 5 (Vd < Vw), that is, the peripheral speed ratio (Vd / Vw) is controlled to be smaller than 1, and dressing is performed. In that case, 70% of the smallest minimum peripheral velocity Vd _min controllable rotary dresser 6 peripheral speed of the superabrasive grinding wheel 5 Vw for effective dressing first dressing step (Vd _min = 0.7Vw ) Is desirable.

The reason for setting the minimum peripheral speed Vd _min rotary dresser 6 as the grinding superabrasive grinding wheel 5 as described in the right column 6 through line 7 on page 81 of Non-Patent Document 1 above The greater the roughness of the grindstone surface that is used surface 5a, the better the sharpness of the grindstone, and as shown in FIG. 2 in the left column of the same page, in the down dress, the rotary dresser 6 and the superabrasive grindstone 5 When the peripheral speed ratio (Vd / Vw) is 1, the roughness of the grindstone surface is maximum, and when the peripheral speed ratio is 1, the roughness gradually decreases in a direction larger than 1 or smaller than 1. This is because a relatively large grindstone surface roughness can be obtained up to a peripheral speed ratio (Vd / Vw) of about 0.7.

  In this first dressing step, since the peripheral speed Vd of the rotary dresser 6 is smaller than the peripheral speed Vw of the superabrasive grindstone 5, a force is applied from the superabrasive grindstone 5 to the rotary dresser 6. Accordingly, the front surface of the abrasive grains (surface on the traveling direction side) and the left and right side surfaces of the abrasive grains that greatly affect the sharpness of the superabrasive grindstone 5 are dressed, and the front surface of the abrasive grains and the left and right side surfaces of the abrasive grains are these It is cleaned by removing foreign matter adhering to the surface.

(2) Second Dressing Step As shown in FIG. 2B, in this second dressing step, the peripheral speed Vd of the rotary dresser 6 in the dressing part α is equal to the peripheral speed Vw of the superabrasive grindstone 5 (Vd = Vw), that is, the peripheral speed ratio (Vd / Vw) is set to 1, and dressing is performed.

  In this second dressing step, the peripheral speed Vd of the rotary dresser 6 is equal to the peripheral speed Vw of the superabrasive grindstone 5, and the peripheral speed ratio (Vd / Vw) is 1. Therefore, page 81 of the aforementioned non-patent document 1 As shown in FIG. 2, the roughness of the grindstone surface becomes the largest. This is because the rotary dresser 6 and the superabrasive grindstone 5 are rotated together because the peripheral speed Vd of the rotary dresser 6 and the peripheral speed Vw of the superabrasive grindstone 5 are equal, so that the rotary dresser 6 is cut. On the other hand, when the dressing is performed so that the abrasive grains before and after the superabrasive grindstone 5 and the bonding material (bond) holding the abrasive grains on both sides are dug up and the worn superabrasive grains are removed. Conceivable.

  Among the abrasive grains held by the dug up binder, for example, a cutting edge that is worn away, a cutting edge that is different from a predetermined cutting direction, and a cutting edge that is not effective for cutting such as a cutting edge that is different from a predetermined cutting angle. Since the abrasive grains having blades have a large dress resistance from the rotary dresser 6 during dressing by the rotary dresser 6, the bonding material holding the abrasive grains is dug up and falls off from the superabrasive grindstone 5.

  On the other hand, since the abrasive grains having a cutting edge effective for cutting have a small dress resistance from the rotary dresser 6 during dressing by the rotary dresser 6, even if the binding material holding the abrasive grains is dug up, the super abrasive grindstone It is thought that it will not drop out of 5. Thereby, it can grind with the abrasive grain which has an effective cutting blade, and the sharpness of the superabrasive grindstone 5 becomes favorable.

(3) Third Dressing Step As shown in FIG. 2C, in this third dressing step, the peripheral speed Vd of the rotary dresser 6 in the dressing part α is larger than the peripheral speed Vw of the superabrasive grindstone 5 (Vd> Vw), that is, the peripheral speed ratio (Vd / Vw) is set larger than 1, and dressing is performed. In that case, the maximum peripheral speed Vd _max of the rotary dresser 6 is desirably 130% (Vd _max = 1.3 Vw) of the peripheral speed Vw of the superabrasive grindstone 5 in order to perform dressing effectively in the third dressing step.

The reason for setting the maximum peripheral speed Vd _max of the rotary dresser 6 in this way is the same as in the case of the first dressing step (1) described above, and the peripheral speed ratio (Vd / Vw) is about 1.3. This is because a relatively large grindstone surface roughness can be obtained.

In the third dressing step, since the peripheral speed Vd of the rotary dresser 6 is higher than the peripheral speed Vw of the superabrasive grindstone 5, a force is applied from the rotary dresser 6 to the superabrasive grindstone 5. Thereby, the rear surface of the abrasive grains of the superabrasive grindstone 5 (the surface opposite to the traveling direction) and the left and right side surfaces of the abrasive grains are dressed, and the rear surface of the abrasive grains and the left and right side surfaces of the abrasive grains adhere to these surfaces. It is cleaned by removing foreign matter.
In the dressing method for the abrasive grindstone 5 of this example, at least two dressing steps of the first to third dressing steps described above are performed.

  Furthermore, in the dressing method of the abrasive grindstone 5 of this example, the rotary dresser 6 is reciprocated in the Z-axis direction (rotational axis direction of the rotary dresser 6) when the first to third dressing steps described above are performed. The feed operation of the rotary dresser 6 is performed. A method for feeding the rotary dresser 6 will be described.

That is, as shown in FIG. 3A, the rotary dresser 6 is in contact with the grinding use surface 5 a of the superabrasive grindstone 5 on the left side 6 a ₁ of the dressing surface 6 a of the rotary dresser 6 in FIG. without a position where a part 6a ₁ other than the portions of the dressing surface 6a is in contact with the ground working surfaces 5a of the superabrasive grinding wheel 5, a diagram of a dressing surface 6a of the rotary dresser 6 shown in FIG. 3 (c) 3 (c) The left part 6a ₂ (which may be the same size as the part 6a ₁ of the dressing surface 6a or may be different from the part 6a ₁ described above) is a superabrasive grindstone 3 between the position where the portion 5a ₂ other than the part 6a ₂ of the dressing surface 6a is in contact with the grinding surface 5a of the superabrasive grindstone 5 without contacting the grinding surface 5a. The dressing surface 6a of the dresser 6 is entirely superabrasive. The rotary dresser 6 is reciprocated a predetermined number of times via a position that contacts the grinding use surface 5a of the grindstone 5 (a position where the center in the width direction of the rotary dresser 6 coincides with the center in the width direction of the superabrasive grindstone 5). A feeding operation is performed. In this case, the feed speed of the rotary dresser 6 can be set to be the same when the rotary dresser 6 moves forward and back, or can be set to be different from each other. By changing the feed movement speed when the rotary dresser 6 reciprocates, the cylindrical surface (outer peripheral surface) of the rotary dresser 6 can be planarized and the dressing of the superabrasive grindstone 5 can be made even more effective. Become.

  The number of reciprocations of the rotary dresser 6 in this feeding operation includes the first to third dressing steps, the degree of wear of the grinding surface 5a of the superabrasive grindstone 5, the material of the superabrasive grindstone 5, the dimensions (size) of the workpiece W ), Depending on the material of the workpiece W and the material of the rotary dresser 6, but generally 1 to 10 times / minute is desirable.

  Further, in the dressing method for the abrasive grindstone 5 of this example, the rotary dresser 6 is centered on the superabrasive grindstone 5 in the Y-axis direction (vertical direction in FIG. 1) when the first to third dressing steps described above are performed. The rotary dresser 6 is cut by a predetermined small amount of movement.

  The cutting amount of this cutting operation is set at the start of dressing and can be set so as not to change in all dressing processes thereafter. Further, the cutting depth can be set so as to change when at least one dressing process is changed when the dressing process is changed after being set at the start of dressing. Furthermore, in the feeding operation of one dressing process, it can be set to change when the moving direction of the at least one rotary dresser 6 changes when the moving direction changes between the forward movement and the backward movement of the rotary dresser 6.

  This depth of cut includes the first to third dressing steps, the degree of wear of the grinding use surface 5a of the superabrasive grindstone 5, the material of the superabrasive grindstone 5, the dimension (size) of the workpiece W, Although it depends on the material and the material of the rotary dresser 6, it is generally desirable that the cutting depth is about 1 to 16 μm / time.

Each peripheral speed Vd and the minimum peripheral speed Vd _min and the maximum peripheral speed Vd _max of the rotary dresser 6 in the first and third dressing process, selection of at least two dressing step of the first to third dressing process, the rotary The number of reciprocations of the dresser 6, the feeding speed, the difference in the feeding speed during the reciprocating movement, and the cutting and cutting operation of the rotary dresser 6 are all the degree of wear of the grinding surface 5 a of the superabrasive grindstone 5, It is appropriately set according to the material of the superabrasive grindstone 5, the dimension (size) of the workpiece W, the material of the workpiece W, and the material of the rotary dresser 6.

  Next, an example of the operation of the dressing method of the abrasive grindstone 5 of this example configured as described above will be described. In the dressing method of this example, the case where the abrasive grindstone 5 is dressed when the difficult-to-cut material is ground by the abrasive grindstone 5 rotating at the set rotational speed will be described.

  In FIG. 1, a grinding worker sets a predetermined position on the Z-axis direction moving table 4 of the square surface grinding machine 1 in order to grind a workpiece W made of a difficult-to-cut material. At this time, the grinding operator performs grinding for the workpiece W based on the material of the workpiece W, the size of the workpiece W, the grinding amount of the workpiece W, the material of the superabrasive grindstone 5, and the like. The moving speed of the X-axis direction moving table 3, the moving width of the X-axis direction moving table 3, the peripheral speed Vw of the superabrasive grindstone 5, and the cutting amount of the superabrasive grindstone 5 are set, and the set data is sent to the control device. input. The control device rotates the superabrasive grindstone 5 at a rotational speed corresponding to the set peripheral speed Vw based on the input data, and in the Z-axis direction with respect to the end face of the superabrasive grindstone 5 and the end face of the workpiece W. Then, the X-axis direction moving table 3 is reciprocated at a set moving speed and a set moving width. Thereby, the superabrasive grindstone 5 grinds the predetermined area | region of the to-be-ground object W by the first feed.

  At the same time, the grinding operator can determine the material of the workpiece W, the size of the workpiece W, the amount of grinding of the workpiece W, the degree of wear of the grinding surface 5a of the superabrasive grindstone 5, the material of the superabrasive grindstone 5, and Based on the material of the rotary dresser 6 and the like, at least two dressing steps of the first to third dressing steps employed for dressing the superabrasive grindstone 5 at this time, and the rotary dresser in each dressing step employed. 6 and the above-described rotary dresser 6 feeding method (feed speed, number of reciprocating movements during feeding operation, control of different feeding speeds during forward movement and backward movement, etc.), and rotary dresser 6 Set the cutting depth and input the data set in the control unit. Based on the input data, the control device rotates at a rotational speed corresponding to the set peripheral speed Vd in the first dressing process employing the rotary dresser 6 and positions the rotary dresser 6 in the Z-axis direction to the set cutting amount. Further, the rotary dresser 6 is rotated by the set feed method, and the rotary dresser 6 is rotated at the set peripheral speed Vw to dress the grinding use surface 5a of the superabrasive grindstone 5 that is grinding the workpiece W.

  When the set number of reciprocating movements during the feeding operation in the first dressing process is completed, the grinding use surface 5a of the superabrasive grindstone 5 is dressed by the next dressing process employed in the same manner as in the first dressing process. When the set number of reciprocating motions during the feeding operation in the next dressing process is completed, when two dressing processes are adopted among the first to third dressing processes, the dressing of the grinding use surface 5a of the superabrasive grindstone 5 is performed. finish. Further, when all dressing steps among the first to third dressing steps are adopted, the grinding use surface 5a of the superabrasive grindstone 5 is dressed in the last dressing step in the same manner as each dressing step described above. To do. Then, when the set number of reciprocating motions during the feeding operation in the last dressing process is finished, the dressing of the grinding use surface 5a of the superabrasive grindstone 5 is finished, and at the same time, the object to be ground in the first feed by the superabrasive grindstone 5 Grinding of the predetermined area of W is completed.

When the grinding of the predetermined region of the workpiece W by the first feed by the superabrasive grindstone 5 is completed, the control device moves the Z-axis direction moving table 4 to set the next feed amount for grinding, and In the same manner as described above, the superabrasive grindstone 5 grinds the next predetermined region of the workpiece W with the next set feed amount. At this time as well, as described above, the rotary dresser 6 simultaneously rotates at the set peripheral speed Vw to dress the grinding use surface 5a of the superabrasive grindstone 5 that is grinding the workpiece W.
Thus, dressing of the grinding use surface 5a of the superabrasive grindstone 5 by the rotary dresser 6 is performed until the grinding of the workpiece W in the first feed by the superabrasive grindstone 5 is completed.

  By the way, by adopting at least two dressing steps among the first to third dressing steps described above, the set peripheral speed Vd of the rotary dresser 6 is changed with respect to the superabrasive grindstone 5 rotating at the set peripheral speed Vw. Thus, the grinding use surface 5a of the superabrasive grindstone 5 can be dressed more effectively. In particular, all the dressing steps of the first to third dressing steps are adopted, and the third dressing step where Vd> Vw is performed first, then the second dressing step where Vd = Vw is performed, and finally Vd <Vw < Performing the first dressing process with Vw, or adopting all the dressing processes of the first to third dressing processes and performing the second dressing process with Vd = Vw first, and then Vd> Vw It is desirable to perform the third dressing step and finally perform the first dressing step where Vd <Vw, so that the grinding use surface 5a of the superabrasive grindstone 5 can be most effectively dressed. That is, it is best to adopt all the dressing steps of the first to third dressing steps and to perform the first dressing step at least last. In this way, as described above, the abrasive having an ineffective cutting edge in the second dressing step falls off from the superabrasive grindstone 5 and remains on the superabrasive grindstone 5 and is effective for cutting. Since the front surface of the abrasive grains that greatly influence the sharpness of the superabrasive grindstone 5 is effectively dressed by the first dressing step performed last, the sharpness of the superabrasive grindstone 5 is better. It will be a thing.

  In the above example, the dressing of the superabrasive grindstone 5 by the rotary dresser 6 is performed when the workpiece W is ground by the superabrasive grindstone 5, but the dressing method of the present invention is performed by the superabrasive grindstone 5. Similarly, when the workpiece W is not ground, the superabrasive grindstone 5 can be dressed by the rotary dresser 6 while the superabrasive grindstone 5 is rotated at the set peripheral speed Vw.

  In addition, in at least two dressing steps employed among the first to third dressing steps, when shifting from the previously performed dressing step to the next dressing step, the transition is continuously performed as in the above example. It is also possible to transition from the end of the previous dressing process to the next dressing process intermittently with a lapse of time. Similarly, the reciprocating movement of the rotary dresser 6 can be performed continuously in the forward and backward directions, or can be performed intermittently. Furthermore, the feed speed during the forward movement and the feed speed during the backward movement of the rotary dresser 6 can be arbitrarily set during the dressing operation, and the cutting operation of the rotary dresser 6 can be arbitrarily set during the dressing operation. it can. Furthermore, when dressing the superabrasive grindstone 5 with the rotary dresser 6, the cutting fluid is applied to the dressing part α of the superabrasive grindstone 5 to efficiently remove unwanted foreign matter scraped from the superabrasive grindstone 5. In addition, the superabrasive grains of the superabrasive grindstone 5 can be effectively cooled.

  Further, when the diameter of the rotary dresser 6 is reduced by the dressing operation and the peripheral speed Vd of the rotary dresser 6 is decreased, the peripheral speed Vd is set to the set peripheral speed, that is, the set peripheral speed ratio Vd. It is desirable to correct so as to be / Vw.

  According to the dressing method of the superabrasive grindstone 5 of this example and the square surface grinder 1 configured as described above, the peripheral speed Vd of the rotary dresser 6 made of GC or WA abrasive grindstone is set to the circumference of the superabrasive grindstone 5. A first dressing step in which dressing is performed with a setting smaller than the speed Vw; a second dressing step in which dressing is performed with the peripheral speed Vd of the rotary dresser 6 set equal to the peripheral speed Vw of the superabrasive grindstone 5; and the rotary dresser 6 is set to be larger than the peripheral speed Vw of the superabrasive grindstone 5, and at least two dressing steps including the third dressing step for performing dressing are performed, so that the circumference of the superabrasive grindstone 5 is increased during the dressing step. Since the superabrasive grindstone 5 is dressed by changing the peripheral speed ratio between the speed Vw and the peripheral speed Vd of the rotary dresser 6, dressing can be performed more efficiently. Can.

  Therefore, it is possible to efficiently purify (clean) foreign matters such as chips adhering to the superabrasive grindstone 5. Therefore, the wear of the superabrasive grindstone 5 can be reduced, the occurrence of clogging and clogging in the superabrasive grindstone 5 can be suppressed, and the superabrasive grindstone 5 can be sharpened reliably and satisfactorily. As a result, the sharpness of the superabrasive grindstone 5 is sharpened to eliminate chattering when the workpiece W is ground by the superabrasive grindstone 5, so that sharp and stable grinding can be performed, and the dressing effect can be improved. Can be improved. This eliminates chatter during grinding of the workpiece W by the superabrasive grindstone 5 and enables sharp and stable grinding, further improving the grinding accuracy and further improving the productivity of grinding. In addition, the cost for grinding can be reduced.

  Further, by continuously performing at least two dressing steps among the first to third dressing steps having different peripheral speeds Vd of the rotary dresser 6, the grinding use surface 5a of the superabrasive grindstone 5 can be efficiently dressed. Therefore, planarization of the cylindrical surface (outer peripheral surface) of the rotary dresser 6 and equalization of dressing of the superabrasive grindstone 5 can be achieved more effectively.

  In particular, by adopting the second dressing process in which the peripheral speed Vd of the rotary dresser 6 and the peripheral speed Vw of the superabrasive grindstone 5 are set to be the same in the at least two dressing processes described above, An appropriate amount of the binder that is held can be removed, and the superabrasive particles that have been worn or worn can be efficiently removed, and new superabrasive grains can be grown spontaneously. Therefore, the wear of the superabrasive grindstone can be further reduced to further prevent clogging and clogging of the superabrasive grindstone 5, and the superabrasive grindstone 5 can be sharpened more reliably and satisfactorily.

  Further, among the difficult-to-cut materials that are the material to be ground W, particularly when high-hardness diamond is ground with the superabrasive grindstone 5 made of diamond, the above-described grinding is performed on the workpiece W with the superabrasive grindstone 5. Since the superabrasive grindstone 5 is effectively dressed by changing the peripheral speed Vd of the rotary dresser 6 and dressing the superabrasive grindstone 5 as described above, the wear of the expensive diamond of the superabrasive grindstone 5 is reduced. Can be reduced. Therefore, the sharpness of the superabrasive grindstone 5 can be kept good and stable for a long time, and diamond can be always ground with high efficiency. This facilitates the production of diamond by grinding, further improves productivity and further reduces the cost of grinding.

  In particular, since the dressing of the superabrasive grindstone 5 by the rotary dresser 6 can be performed during the grinding of the workpiece W by the superabrasive grindstone 5, the difficult-to-cut material disclosed in Non-Patent Document 2 described above. It is also possible to obtain an effect in grinding processing.

FIG. 4 is a perspective view schematically and schematically showing an example of a rotary circular table type grinding machine to which an example of the embodiment of the present invention is applied. In addition, the same code | symbol is attached | subjected to the same component as the example shown in above-mentioned FIG. 1, and the detailed description is abbreviate | omitted.
In the rotary circular table type grinding machine 1 of this example, the X-axis direction moving table 3 is not provided in the example shown in FIG. An axial direction moving table 4 and a rotary circular table 8 that is rotatably provided on the Z-axis direction moving table 4 and on which an object (workpiece) W is set are provided. The other configuration of the grinding machine 1 in this example is the same as the example shown in FIG. Moreover, the effect of the grinding machine 1 of this example is substantially the same as the example shown in FIG.

  FIG. 5 is a perspective view schematically and schematically showing an example of a cylindrical grinder to which an example of the embodiment of the present invention is applied. In addition, the same code | symbol is attached | subjected to the same component as the example shown in above-mentioned FIG. 1, and the detailed description is abbreviate | omitted.

  In the cylindrical grinding machine 1 of this example, in the example shown in FIG. 4, instead of the rotary circular table 8 in the Z-axis direction moving table 4, known support means 9, 10 that support both ends of the cylindrical workpiece W are provided. Is provided. These support means 9 and 10 support the cylindrical workpiece W so that the axial direction thereof is the Z-axis direction. Further, like a known cylindrical grinder, the superabrasive grindstone 5 is disposed so as to grind the outer peripheral surface of the cylindrical workpiece W. The other configuration of the grinding machine 1 of this example is the same as the example shown in FIG. Moreover, the effect of the grinding machine 1 of this example is substantially the same as the example shown in FIG.

  In addition to diamond, there are pure iron, nickel, copper, aluminum, titanium, and the like as the high-hardness workpiece W, but when these workpieces W are ground with the superabrasive grindstone 5, they are also described above. As with, grinding can be performed with high efficiency. In addition to these high-hardness workpieces W, other difficult-to-cut materials as well as other workpieces can be effectively dressed.

  The dressing method for a superabrasive grindstone of the present invention and the dressing apparatus used in this method can be suitably used for dressing a superabrasive grindstone for grinding a workpiece (workpiece) such as a difficult-to-cut material. .

1 is a perspective view schematically and schematically showing an example of a square surface grinder to which an example of an embodiment of a dressing apparatus for a superabrasive grindstone according to the present invention is applied. The dressing method of the superabrasive grindstone concerning this invention is demonstrated, (a) is a figure which shows a 1st dressing process, (b) is a figure which shows a 2nd dressing process, (c) is a figure which shows a 3rd dressing process. It is. (A) thru | or (c) is a figure explaining the feed of the rotary dresser in the dressing method shown in FIG. 1 is a perspective view schematically and schematically showing an example of a rotary circular table type grinding machine to which an example of an embodiment of the present invention is applied. 1 is a perspective view schematically and schematically showing an example of a cylindrical grinding machine to which an example of an embodiment of the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Grinding machine, 2 ... Main body, 3 ... X-axis direction moving table, 4 ... Z-axis direction moving table, 5 ... Super-abrasive grindstone (grinding wheel), 6 ... Rotary dresser, 7 ... Dressing device, 8 ... Rotating circle Table, 9, 10 ... support means, W ... workpiece

Claims (5)

The rotary dresser is rotated so that the peripheral speed is the same as the rotational speed of the superabrasive grindstone in the dressing part while the rotary dresser is cut in the superabrasive grindstone. In the dressing method of the superabrasive grindstone for dressing the superabrasive grindstone by reciprocating in the feed direction parallel to the
A first dressing step of dressing the superabrasive grindstone by setting a peripheral speed of the rotary dresser smaller than a peripheral speed of the superabrasive grindstone; and a peripheral speed of the rotary dresser as a peripheral speed of the superabrasive grindstone A second dressing step for dressing the superabrasive wheel with the same setting, and a third dressing for dressing the superabrasive wheel with the peripheral speed of the rotary dresser set larger than the peripheral speed of the superabrasive wheel Process,
A dressing method for a superabrasive grindstone, wherein the rotary dresser dresses the superabrasive grindstone by at least two dressing steps among the first to third dressing steps. The rotary dresser is rotated so that the peripheral speed is the same as the rotational speed of the superabrasive grindstone in the dressing part while the rotary dresser is cut in the superabrasive grindstone. In the dressing method of the superabrasive grindstone for dressing the superabrasive grindstone by reciprocating in the feed direction parallel to the
A first dressing step of dressing the superabrasive grindstone by setting a peripheral speed of the rotary dresser smaller than a peripheral speed of the superabrasive grindstone; and a peripheral speed of the rotary dresser as a peripheral speed of the superabrasive grindstone A second dressing step for dressing the superabrasive wheel with the same setting, and a third dressing for dressing the superabrasive wheel with the peripheral speed of the rotary dresser set larger than the peripheral speed of the superabrasive wheel Process,
A dressing method for a superabrasive grindstone, wherein the rotary dresser dresses the superabrasive grindstone at least last in the first dressing step.   Each dressing process at the time of reciprocating motion of the rotary dresser is repeated continuously for a set number of times set in each process, or each dressing process at the time of reciprocating motion of the rotary dresser is intermittently set to each process. 3. The method for dressing a superabrasive grindstone according to claim 1, wherein the dressing is repeated for a set number of times.   The dressing method for a superabrasive grindstone according to any one of claims 1 to 3, wherein a moving speed at the time of forward movement and a moving speed at the time of backward movement of the rotary dresser are changed. A dressing apparatus for a superabrasive grindstone used in the dressing method for a superabrasive grindstone according to claim 3 or 4,
Rotation drive means for rotating the rotary dresser so that the peripheral speed is the same as the peripheral speed of the abrasive grindstone in the dressing section, and the rotary dresser is moved in the cutting direction with respect to the superabrasive grindstone A cutting means, a feeding means for reciprocating the rotary dresser in the feeding direction with respect to the superabrasive grindstone, and a control device for controlling the rotation driving means, the cutting means and the feeding means,
The control device controls the rotation driving means so that the rotary dresser has respective peripheral speeds when performing at least two dressing steps among the first to third dressing steps, or the rotary dresser. Controls the rotational drive means so that the peripheral speeds at the time of performing at least two dressing steps among the first to third dressing steps are controlled, and the feed movement speed of the rotary dresser is the forward and backward movements. A dressing device for a superabrasive grindstone, which is a control device for controlling the feeding means so as to change depending on time.

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