JPH0639056B2 - Method and device for grinding stone of NC tool grinder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and an apparatus for shaping a grindstone for tool grinding, and more particularly to a borazon or resinoid mounted on an NC tool grinder for performing tool grinding with numerical control. Method for reshaping a super-abrasive grindstone such as diamond, and shaping such as dressing at any stage of the tool grinding process using the grindstone, and directly without removing the grinding wheel And equipment.

[Prior art]

In recent years, with the progress of grinding wheel processing technology, in the field of tool grinding wheels, borazone (cubic boron nitride) crystal grinding wheels, resinoid grinding wheels, and diamond grinding wheels have replaced conventional alundum grinding wheels and silicon carbide grinding wheels. Tend to be used. The conventional idea regarding such a tool grinding wheel is
Since there are many irregular shapes known as convex R shape, concave R shape, angular shape, etc. of the grinding wheel surface corresponding to the shape of the machining tool to be ground, the shaping machine tends to be expensive, Therefore, a general method is to return the product to a specialized grinding wheel manufacturer equipped with a shaping machine and request shaping using a high-pressure and wet method using a shaping machine. Was there.

[Problems to be solved by the invention]

However, at a work site equipped with an NC tool grinder, even in the case of superabrasive grindstones such as borazons, resinoids, and diamonds, the grindstone is reshaped and sharpened with the grindstone attached to the NC tool grinder. It is becoming more and more desirable to provide a method and an apparatus for obtaining the same from the viewpoints of improving the tool grinding work efficiency, speed, and achieving a correct shape for a desired shape. In addition, the superabrasive grindstone has a higher tool unit price than conventional alundum-type ordinary grindstones.Therefore, superabrasive grains are formed in a structure in which a superabrasive grain is provided as an abrasive grain layer on the core layer of steel or the like. Therefore, from the economical point of view, there is a drawback that the reforming (truing) and the conspicuousness (tressing) that depend on the skill of a professional skilled worker cannot achieve the economically efficient shaping that matches the structural economics. Therefore, it is desired to provide a device that can realize the grindstone shaping by a constant and automated shaping method at a required time while the grindstone is mounted on the NC tool grinder without relying on the skill. In particular, if the grindstone can be shaped on the NC tool grinder, it is possible to prevent deterioration of processing accuracy and surface roughness due to wobbling of the grindstone as compared with the case where the grindstone is once removed, and therefore, there is a great demand. .

Therefore, the object of the present invention is to solve the above-mentioned problems by N
Prior to the start of the tool grinding process using the C tool grinder,
Alternatively, it is another object of the present invention to provide a grinding stone shaping method and device capable of relatively easily and highly accurately shaping a grinding stone during a tool grinding process.

[Solution means and action]

According to the present invention, there is provided a method for shaping a tool grinding wheel of an NC tool grinding machine, which comprises rotating one or more of the tool grinding wheels and projecting one or a plurality of dot-like shapes protruding toward a surface to be shaped of the tool grinding wheel. The tool is rotated around one rotation axis along a circular locus having a contact point on the surface to be shaped of the tool grinding wheel, and the tool grinding wheel and the reshaping tool are relatively opposed to each other in the rotation axis direction. By feeding, and controlling the ratio of the rotation speed of the tool grinding wheel to the rotation speed of the reshaping tool by NC control, the surface to be shaped of the tool grinding wheel is continuously formed along a spiral orbit. An eye that is formed on the connecting surface of the crater and is corrected to a desired shape consisting of a shape determined by the envelope of the crater connecting surface, and then the shaped surface abrasive grain binder of the tool grinding grindstone after the shape correction is removed. To stand up A method for shaping a grindstone of an NC tool grinder is provided so as to shape the grinding surface of the grindstone without removing the grindstone from the NC tool grinder, and in order to carry out such a shaping method, an NC A shaping device for shaping a tool grinding wheel of a tool grinder, comprising: a shank portion to be mounted in a tool spindle hole for mounting a tool to be ground of the NC tool grinder; and a shank portion protruding in a radial direction from a tip of the shank portion. And one or a plurality of reshaping tools provided at, and placed at the position of the rear part in the axial direction with respect to the reshaping tool,
And a dressing brush protruding substantially radially from the shank portion, which is in rotational contact with the surface to be shaped of the tool grinding grindstone mounted on the grindstone shaft of the NC tool grinder to form an envelope of the crater connecting surface. There is provided a grindstone shaping device for an NC tool grinding machine, which is configured to form a predetermined grindstone shape to be defined and to perform a shaping process which is composed of conspicuousness of the crater connecting surface. Then, according to this shaping device, the whetstone to be shaped on the whetstone shaft is rotated, and the shaping tool of the shaping device mounted in the tool shaft hole is swung, and the contact between the two causes a spiral direction on the surface to be shaped. On the NC tool grinder, a large number of craters are continuously formed on the crater, the desired grindstone correction shape is formed by the envelope of the formed craters, and then the surface to be shaped is sharpened with a dressing brush. The tool grinding grindstone can be shaped with, and even if the grindstone is a superabrasive grindstone, the shaping process can be easily performed.
Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

〔Example〕

FIG. 1 is an enlarged cross-sectional view of a tool spindle part of an NC tool grinder in which a grindstone shaping device according to the present invention is mounted on a tool spindle, and FIGS. 2 and 3 are front views of the NC tool grinder. And a plan view and FIG. 4A are plan views showing a state of a continuous crater formed on the surface to be shaped of the tool grinding wheel subjected to the shaping treatment, and FIGS. 4B and 4C are craters continuously formed on the spiral line. Axis perpendicular sectional view, FIG. 4D is a sectional view showing a grindstone shaping shape determined by the envelope, FIGS. 4E, 4F are axial parallel sectional views of the crater, and FIG. 4G is determined by the envelope. FIG. 5 is a cross-sectional view showing the shape of a grindstone formed, and FIG. 5 is an enlarged cross-sectional view for explaining the dressing action of the dressing brush.

First, referring to FIGS. 2 and 3, the NC tool grinder has a bed 1 at the lowermost part of the machine body, and a jaw-shaped base 2 of a revolving arm 3 is fixed to one side surface of the bed 1. The revolving arm 3 is provided so as to be revolvable around the W axis through an appropriate speed reduction mechanism by the drive of the drive motor Mw. A work headstock 4 is provided on the revolving arm 3 so as to be movable in the left and right directions indicated by U, and is moved left and right by driving a drive motor Mu. The machining headstock 4 includes a spindle 5 having a tool mounting hole into which a machining tool to be ground is mounted, and the spindle 5 is driven by a drive motor Ma.
It is rotationally driven around the rotation axis A at a variable speed via the belt / pulley mechanism 6.

On the other hand, on the bed 1, separated from the swivel arm 3,
Column 10 having a spindle head 9 equipped with a tool grinding wheel 8
Is movably mounted in the axial direction (Y-axis direction) in a horizontal plane orthogonal to the turning axis W of the turning arm 3. The tool grinding wheel 8 is provided so as to face the spindle 5.
The machining tools mounted on the spindle 5 are subjected to a grinding action at positions close to each other. Y in column 10 above
The displacement in the axial direction is driven by the drive motor My. Further, the spindle head 9 is attached so as to be movable and displaceable in the vertical Z-axis direction along the column 10, and a desired displacement is performed in the vertical direction by driving the drive motor Mz. The grindstone 8 for tool grinding attached to the spindle head 9 is driven by a drive motor Mm to rotate at high speed for grinding. In the NC tool grinder having the above configuration, the above-mentioned drive motors M
w, Mu, My, Mz are numerically controlled by a well-known NC control device (not shown) to grind the tool, index around the tool axis line, lead according to the twist of the tool blade, rake angle, grindstone The cutting amount and the like are controlled to provide an appropriate grinding action.

In the NC tool grinder described above, when the grinding wheel 8 for tool grinding is deformed, clogged, or the like, it is reshaped by truing, and dressing is performed to sharpen the grindstone and correct the shape. Implementation is required. The present invention is conventional, particularly in the case of superabrasive grindstones, etc.
The tool grinding wheel 8 should be removed once and requested to a tool maker to perform the shaping process, so that the shaping process can be performed with the spindle head 9 of the NC tool grinder still attached. It is something to do.

As shown in FIG. 1, according to the present invention, the tool grinding wheel 8
When performing a truing or dressing shaping process, the grindstone shaping device 20 is always mounted in the tool mounting hole 5a (usually a taper hole) of the spindle 5 of the work spindle stock 4 in which the machining tool to be ground is mounted. . Here, the main shaft 5 is rotationally driven around the rotation axis A by the drive motor Ma as described above, but the main shaft 5 is supported by the headstock 4 by the rotary bearings 11 a and 11 b, and the main shaft 5 is supported by the belt / pulley mechanism 12. Driven to rotate. The spindle 5 has the tool mounting hole 5a, and a through hole is formed at the rear of the tapered tool mounting hole 5a. A drawbar 13 is provided at the rear end of the main shaft 5, and a draw screw 13a formed at the tip thereof.
Thus, the tool or the rear end of the grindstone shaping device 20 is firmly fixed in the tool mounting hole 5 and is rotated together with the main shaft 5. The grindstone shaping device 20 has a tool mounting hole 5a.
21 with a tapered shank that matches the taper of the
The tip portion 22 of the shaft body portion 21 that protrudes outward from the tip of the main shaft 5 is formed into a cylindrical shaft having a step portion, and abuts against the step portion of the cylindrical shaft 22 to rotate the boss. 23 is attached by tightening with a nut 24. Side plates 24a and 24b are provided on both sides in the axial direction of the rotary boss 23, and a diamond bite 25 for truing is attached to a rear portion of the front side plate 24a so as to project in the radial direction with respect to the rotation axis A. Although one diamond bite 25 is attached in the illustrated example, a plurality of the same diamond bite 25 may be attached at equal intervals in the circumferential direction, if necessary. When two or more diamond cutting tools 25 are attached, the adjusting screws 26 are adjusted so that both projecting amounts are equal to the rotation axis A.
Is provided. The adjusting screw 26 has a head 26a engaged with the diamond bite 25 at its inner end. When the adjusting screw 26 advances and retreats by rotation, the diamond bite 25 also advances and retracts in the radial direction by engaging with the head 26a. There is. The diamond bite 25 is fixed by the clamp bolt 27 after the amount of advance / retreat in the radial direction is adjusted. The rake angle in the truing action of the diamond bite 25 is set to an appropriate rake angle by adhering the spacer 28 to the back surface of the bite 25 and adjusting the thickness thereof. The tip of the diamond cutting tool 25 has a structure having an edge for scooping the surface of the tool grinding wheel 8 when it comes into contact with the surface to be shaped.

By the way, the rotary boss 23 is further provided with the above-mentioned diamond bite 2
A brush 29 for dressing is attached to the rear of the shaft 5 in the axial direction. This brush 29 is made of nylon, carbon steel,
Brushes 29 made of stainless steel and having a single-row structure are planted in the illustrated example. This brush 29 is a rotary boss 23
When it rotates together with the surface to be shaped of the grindstone 8, as shown in FIG. 5, a setting action for removing the binder made of a normal bonding material that bonds the abrasive grains to expose the abrasive grains, that is, It performs a dressing action, and is provided with a proper rake angle Θ in the rotation direction to improve dressing efficiency.

In order to attach the brush 29 to the rotary boss 23, an axial groove is formed in the surface of the rotary boss 23 in advance, and the end of the brush 29 is inserted into this groove and fixed with a wedge material 30. The mounting method is adopted. As shown in FIG. 5, the brush 29 may be arranged in a plurality of rows at appropriate intervals in the circumferential direction of the rotary boss 23 to improve the dressing efficiency.

Further, as shown in FIG. 1, a liquid passage 40 is formed in the center of the shaft portion 21 of the grindstone shaping device 20, and the liquid passage 40 is formed.
Is connected to a well-known rotary joint 50 through a through passage 13b formed in the center of the draw bar 13 described above, and the rotary joint 50 is provided outside, that is, on a side portion of the NC tool grinder in advance. The grinding fluid that is sucked and supplied by the pump 52 from the grinding fluid tank 51 is sent. Therefore, the grinding liquid that has passed through the rotary joint 50 is sent into the grindstone shaping device 20 through the through passage 13b and the liquid passage 40. Here, the liquid passage 40 further passes through the radial liquid passage 41 and enters the liquid chamber 42 formed between the shaft portion 21 and the rotary boss 23, and from there, it is inclined in the radial direction according to the injection angle. The grinding fluid is supplied under high pressure to the dressing action point of the brush 29 and the truing action point of the diamond bite 25 through the liquid passages 43 and 44. That is, wet grinding is possible, damage due to heat generation of the diamond bite 25 is prevented, and a dressing effect for cleaning the surface to be shaped of the grinding wheel 8 is imparted.

Next, the operation of truing and dressing of the grindstone shaping device 20 according to the embodiment of the present invention will be described.

The shaft body portion 21 of the grindstone shaping device 20 is attached to the mounting hole 5 of the tool spindle 5.
It is mounted on a and is rotated together with the main shaft 5 around the axis A by the drive motor Ma. At this time, the grindstone 8 for tool grinding attached to the spindle head 9 is also placed in a rotating state by the drive of the drive motor Mm. First, in the truing action, the grindstone shaping device 20 is moved in the U-axis direction (see FIG. 2) to reach the contact position with the grindstone 8, and the diamond bite 25 is brought into contact engagement with the surface to be shaped of the grindstone 8. . At this time, since the diamond bite 25 is rotating together with the rotary boss 23, it is engaged with the surface to be shaped once per rotation. Further, a relative displacement is given also in the axial direction so as to give a reshaping action over the entire length of the surface to be shaped of the grindstone 8. At this time, the surface shape of the surface to be shaped of the grindstone 8 after truing is
Due to the contact with the surface to be shaped of the diamond bite 25, a large number of drilling holes (craters) are continuously formed on the surface due to the cutting effect of the bite cutting edge for a short period of time. The shape is determined by the envelope surface of the convex portion. This surface shape is therefore the number of revolutions of the grindstone 8, the number and number of revolutions of the diamond bite 25, the diameter from the axis of rotation to the tip of the diamond bite 25 and the diameter of the grindstone 8, the radius of roundness of the tip of the diamond bite 25 (nose diameter). ), It is geometrically determined in relation to the axial relative feed speed of the two. FIG. 4A is a plan view showing a continuous state of the craters formed on the surface to be shaped of the grindstone 8 in the circumferential direction, and the craters are continuously arranged in a spiral shape due to the relative feed in the axial direction of the grindstone 8. Will be. Truing by connecting such craters has a big difference from the conventional truing method. In other words, in the conventional truing method, by fixing the diamond point to one point, and by making relative contact with the grindstone,
Although a threaded groove is cut on the outer circumference of the grindstone, the truing method according to the present invention positively forms many craters or pockets on the surface to be shaped of the grindstone (see FIGS. 4B and 4C). ). Therefore, such a crater or pocket acts as a tip pocket that captures the grinding particles, especially in the case of resinoid grindstones that are superabrasive particles, and at the same time also acts as an oil reservoir hole, and during the tool grinding operation Properly prevent burning due to frictional heat with the tool and also prevent clogging. The 4th D
The figure illustrates that the envelope has the outer shape of the reshaped shape of the grindstone 8. Further, FIGS. 4E and 4F show crater shapes in the axial cross section. Particularly, in the case where the surface shape is in the axial direction, from the continuous arrangement of the axially uneven surface determined by the tip diameter of the diamond bite 25 and the axial feed. It shows that it is a rough surface and, of course, since the number of rotations is many,
The irregularities overlap each other, and the envelope surface determines the outer shape of the grindstone. FIG. 4G shows the envelope in the axial direction.

Next, the dressing operation performed after the above-mentioned truing operation is completed will be described.

The dressing of the surface to be shaped of the grindstone 8 is performed by the brush 29, and the truing removes the bond from the surface to be shaped that has been reshaped to make it sharp. In particular, as shown in FIG. 5, when the brush 29 is given an appropriate rake angle Θ for dressing, it assists the formation of the tip pocket, which is extremely effective.

As is clear from the above description, according to the grindstone shaping processing method of the present invention executed by using the grindstone shaping device 20 according to the embodiment of the present invention, the crater or the pocket is positively connected to the surface to be shaped of the grindstone. The shape of the grindstone after truing is determined based on the enveloping surface. here,
When designing and manufacturing the rotary boss 23 of the grindstone shaping device 20, it is possible to implant a plurality of diamond tools 25 and implant a plurality of rows of brushes. Optimal truing and dressing combined can be achieved. Moreover, the rotation of the spindle 5, the rotation of the spindle head 9 of the grindstone, the selection of the relative axial feed speed, and the addition of an oscillation action when necessary can be controlled directly using the NC control device for controlling the tool grinding action. In addition, the shaping process can be automated and quantified, and there is no need to depend on the skill level of the operator. Moreover, the tool grinding wheel 8 is not removed from the spindle head 9. Since the truing and dressing actions can be performed at required times, the occurrence of runout of the outer periphery of the grindstone, which is apt to be invented by removal, can be suppressed, and the tool grinding accuracy can be improved.

Incidentally, the above-mentioned embodiment is described as intended for a super-abrasive grain grindstone, but the apparatus of this embodiment is not limited to this, and a tool grinding grindstone such as a normal alundum grindstone or a silicon carbide grindstone. Needless to say, it can be used equivalently.

〔The invention's effect〕

As can be understood from the above description, according to the present invention,
The following effects can be obtained.

In other words, since craters or pockets are continuously provided on the surface to be shaped of the grindstone, these function as oil pockets and chip pockets during tool grinding action, prolong the life of the grindstone, and contribute to the prevention of grinding burn. To improve the surface roughness of the surface to be ground.

Moreover, the craters or pockets can be quantified by selecting the shape, number, rotation conditions, etc. of the truing tool in accordance with the conditions such as the rotation speed, diameter, etc. of the grindstone, so that the surface roughness of the grindstone surface can be quantified. It becomes possible to control to. Further, since the amount of truing performed once can be quantitatively grasped by the NC control, it is possible to shape an expensive superabrasive grindstone without wasting it. Therefore, this can also contribute to the extension of the wheel life. Further, even if the surface to be shaped of the grindstone has various irregular shapes, it is possible to freely perform reshaping according to the shape of the grindstone by the feed control of the motor using NC control.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a tool spindle portion of an NC tool grinder in which a grindstone shaping device according to an embodiment of the present invention is mounted on a tool spindle, FIGS. 2 and 3 show an NC tool grinder. A front view and a plan view, and FIG. 4A are plan views showing a state of continuous craters in the circumferential direction formed on the surface to be shaped of the tool grinding grindstone subjected to the shaping treatment, and FIGS. 4B and 4C are spirally continuous. An axially perpendicular sectional view of the formed crater, FIG. 4D is a sectional view showing a grinding stone shaping shape determined by an envelope, FIGS. 4E and 4F are axially parallel sectional views of the crater, and FIG. 4G is Sectional drawing which shows the grindstone shaping | molding shape determined by the envelope, FIG. 5 is an enlarged sectional view explaining the rake angle of the dressing brush and the dressing action by the brush. 4 ... Tool spindle stock, 5 ... Spindle, 5a ... Mounting hole, 8 ... Tool grinding wheel, 9 ... Spindle head, 20 ... Grinding wheel shaping device, 21 ... Shaft body section, 23 ... Rotating boss , 25 ... Diamond bite, 29 ... Brush, 40 ... Fluid passage, 51 ... Grinding fluid tank.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Koyama 3-14-1, Hiyoshi, Kohoku-ku, Yokohama-shi, Kanagawa Keio University Faculty of Science and Engineering Department of Mechanical Engineering Machine Tool Manufacturing Processing Laboratory (72) Inventor Toshifumi Kimura Kanagawa 3-14-1 Hiyoshi, Kohoku-ku, Yokohama-shi, Japan Department of Mechanical Engineering, Mechanical Engineering Department, Department of Mechanical Engineering, Faculty of Science and Technology, Keio University (72) Inventor Satoshi Shimizu 4029 Nakatsu, Aikawa-cho, Aiko-gun, Kanagawa Makino Milling Seiki Co., Ltd.

Claims (4)

[Claims] 1. A method of shaping a tool grinding wheel of an NC tool grinder, which comprises rotating the tool grinding wheel and modifying one or an integer number of dots protruding toward a surface to be shaped of the tool grinding wheel. The tool is rotated around one rotation axis along a circular locus having a contact point on the surface to be shaped of the tool grinding wheel, and the tool grinding wheel and the reshaping tool are relatively opposed to each other in the rotation axis direction. By feeding, and controlling the ratio of the rotation speed of the tool grinding wheel to the rotation speed of the reshaping tool by NC control, the surface to be shaped of the tool grinding wheel is continuously formed along a spiral orbit. Conspicuously formed on the connecting surface of the crater and corrected to a desired shape consisting of a shape determined by the envelope of the crater connecting surface, and then removing the shaped surface abrasive grain binder of the tool grinding wheel after the shape correction I tried to do NC tool grinder of the grinding wheel shaping method comprising. 2. A shaping device for shaping a tool grinding wheel of an NC tool grinder, comprising: a shank portion to be mounted in a tool spindle hole for mounting a tool to be ground of the NC tool grinder; and a tip of the shank portion. 1 provided to project in the radial direction
Or a plurality of point-shaped re-shaping tools, and a dressing brush placed at a position of a rear portion as viewed in the axial direction with respect to the point-shaped re-shaping tool and protruding from the shank portion in a substantially radial direction, Reshaping of the tool grinding grindstone mounted on the grindstone shaft of the NC tool grinder to form a predetermined grindstone shape defined by the envelope of the crater connecting surface by rotating contact with the surface to be shaped, and the conspicuousness of the crater connecting surface A grindstone shaping device for an NC tool grinder, which is characterized by performing a shaping process comprising. 3. A shaping processing liquid supply passage is provided in a central portion of the shank portion, and the shaping processing liquid supply passage is directed from the shaping processing liquid supply passage toward the tip of the shaping tool and toward the notice brush. 2. A machining fluid jetting path for jetting the shaping machining fluid is provided. The grindstone shaping device for the NC tool grinder described in. 4. The reshape tool according to claim 1, which is a diamond tool. Or 3. The grindstone shaping device for the NC tool grinder described in.