JP4368570B2 - Contact establishment method in truing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a contact establishment method in truing for shaping a grindstone of a grinder, and in particular, in truing that allows a grinding wheel and a truing grindstone to be brought out efficiently and safely when truing a grinding wheel such as a thin blade grindstone . The present invention relates to a contact establishment method.
[0002]
[Prior art]
In recent years, the NC and precision of grinders have advanced, and it has become possible to perform machining of molds used for the molding of sophisticated machine parts and grinding of glass and plastic materials directly into precision parts. ing.
[0003]
In the grinding machine, as the grinding process continues, the sharpness of the abrasive grains of the grindstone gradually becomes dull, or the shape of the grindstone wears and changes, so that dressing and truing must be performed as appropriate.
[0004]
Therefore, truing of a thin blade grindstone, which is a disc-shaped grindstone, will be described with reference to FIG.
The thin-blade grindstone 2 is shaped with the truing grindstone 3 at the outer peripheral portion in a state of being attached to the spindle 6 of the spindle head 5 of the grinding machine. The truing grindstone 3 is mounted on a truing device 4 disposed on a grinding machine and is rotated on a horizontal plane. While the truing grindstone 3 is rotated, the blade of the thin blade grindstone 2 is brought into contact with the peripheral edge thereof to perform truing.
[0005]
In order to start truing the thin blade whetstone 2, it is necessary to first adjust the positions of the thin blade whetstone 2 and the truing whetstone 3. Conventionally, in FIG. 8 (a), the vertical lines passing through the center of the thin blade whetstone 2 pass through the center of the truing whetstone 3, and after aligning the center positions of both, the further shown in FIG. 8 (b) is shown. As described above, the thin-headed grindstone 2 was brought into contact with the truing grindstone 3 while moving the spindle head 5 minutely in the direction of the arrow while looking with the naked eye, and this was used as a contact point.
[0006]
[Problems to be solved by the invention]
However, since the conventional technique relies on intuition while visually observing the alignment and contact of the thin blade grindstone 2 and the truing grindstone 3, the center of the thin blade grindstone 2 and the center of the truing grindstone 3 are not exactly aligned. The contact point was put out, and the accuracy of shaping was bad.
[0007]
Further, in order to bring the thin blade whetstone 2 into contact with the truing whetstone 3 and bring out the contact point, the worker often puts his face inside the cover and looks into the thin blade whetstone 2 to work. There was a problem.
[0008]
Accordingly, an object of the present invention is to establish a contact point between a grinding wheel and a truing grindstone safely and efficiently in order to eliminate the problems of the prior art and to perform shaping of the grinding wheel with high accuracy. It is to provide a method for establishing a contact in truing that can be performed .
[0009]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a grinding wheel of a grinding machine having at least three axes of an X axis, a Y axis, and a vertical Z axis orthogonal to each other on a horizontal plane is arranged on a table. In a truing to be shaped with a truing grindstone, a contact establishment method for accurately obtaining a position of a contact point of the grinding grindstone with respect to the truing grindstone before shaping of the grinding grindstone, the coordinates on the X axis of the grinding grindstone Align the center of the grinding wheel and the truing grindstone so that Xt and the coordinates on the X axis of the truing grindstone coincide with each other, rotate the truing grindstone, and lower the grinding grindstone in a rotation-free state. when the truing is close to the grindstone, and the truing grindstone and co-rotation cutting edge of the grinding wheel in contact with the upper surface of the truing grindstone Calculated Z coordinate Zt of the first contact of the grinding wheel, the height of the grinding wheel is retracted from the truing grindstone, from the retracted position, the blade and the grinding wheel in the Z-coordinate Zt of the first contact Lower to a position further lowered by Z1, rotate the truing grindstone, bring the grinding grindstone into a rotation-free state, approach the truing grindstone in the Y-axis direction from the lowered position, and form the blade of the grinding grindstone One of the blade surfaces comes into contact with the outer peripheral portion of the truing grindstone, and when the grinding grindstone rotates together with the truing grindstone, the Y-axis coordinate Yt of the second contact point Pt of the grinding grindstone is determined, and the second The coordinates (Xt, Yt, Zt + Z1) of the contact point Pt are obtained.
[0010]
According to the first aspect of the present invention, the stationary grinding wheel begins to rotate when it comes into contact with the truing grindstone, so that the contact can be reliably detected. Then, the combined center of the grinding wheel and the truing grindstone, the first contact, by to seek contact with the second contact and the order can therefore be found the coordinates of the second contact to safely and accurately .
[0011]
According to a preferred embodiment of the present invention, the contact includes a contact where the cutting edge of the grinding wheel contacts the upper surface of the truing grindstone, and one blade surface forming the blade of the grinding wheel contacts the outer periphery of the truing grindstone. It is a contact point.
[0012]
The grinding wheel is preferably composed of a thin blade grindstone, and a spindle to which the thin blade grindstone is attached is supported by an aerostatic bearing at the spindle head.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a contact establishment method in truing according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a side view showing a grinding machine according to the first embodiment of the present invention, and FIG. 2 is a front view of the grinding machine. 1 and 2, reference numeral 10 indicates a bed. 12 is a column and 14 is a table. A guide rail 11 is laid on the bed 10, and the column 12 is slidably installed on the bed 10 via the guide rail 11 (or a guide made of a V groove). Further, V-grooves 13a and 13b extending in a direction orthogonal to the extending direction of the guide rail 11 are formed on the upper surface of the bed 10, and the table 14 is slidable with the V-grooves 13a and 13b as guide surfaces. is set up. A guide rail 15 extends vertically on the side surface of the column 12, and a spindle head 16 is installed along the guide rail 15 so as to be movable up and down.
[0014]
In this grinding machine, the axis that controls the feed movement of the table 14 is the X axis, the axis that controls the feed movement of the column 12 is the Y axis, and the axis that controls the lifting movement of the spindle head 16 is the Z axis. In this embodiment, in addition to these X axis, Y axis, and Z axis, a C axis for controlling the turning motion of the turntable 27 arranged on the table 14 is provided.
[0015]
As shown in FIG. 2, the X-axis feed mechanism includes an X-axis ball screw 18 driven by an X-axis servomotor 17 and a ball nut (not shown) attached to the lower surface of the table 14. As shown in FIG. 1, the Y-axis feed mechanism includes a Y-axis ball screw 21 driven by a Y-axis servomotor 20 and a ball nut (not shown) attached to the lower surface of the column 12. Similarly, for the Z-axis feed mechanism, a Z-axis servomotor 22 is installed at the top of the column 12 and extends so that the Z-axis ball screw 24 hangs down. A ball (not shown) attached to the spindle head 16 side. A nut is screwed onto the Z-axis ball screw 24.
[0016]
In the spindle head 16, the spindle 25 is supported in a horizontal posture via an aerostatic bearing (not shown). In a state in which the main shaft motor is not energized, the main shaft 25 rotates freely. A grinding wheel 28 is held at the tip of the main shaft 25 so as to be sandwiched between the wheel flanges 26a and 26b. In this embodiment, the grinding wheel 28 is a disk-shaped thin blade wheel, and is attached to the main shaft 25 in a posture that rotates in a plane parallel to the vertical surface.
[0017]
As shown in FIG. 2, a chuck device 29 for fixing a workpiece to be machined is placed on a swivel base 27 installed on the table 14. The swivel base 27 incorporates a C-axis swivel mechanism that is driven by a C-axis servo motor (not shown). In addition to the swivel base 27, a truing device 30 is installed on the table 14 at a position that does not interfere with processing. As shown in FIG. 1, the truing device 30 includes a columnar truing grindstone 31 and a drive unit 32 that rotationally drives the truing grindstone.
[0018]
In FIG. 1, reference numeral 42 indicates an NC device, and reference numeral 44 drives the X-axis servo motor 17, the Y-axis servo motor 20, and the Z-axis servo motor 22 based on a command sent from the NC device 42. Servo drive circuit. The manual pulse generator 46 is used when the position of the grinding wheel 28 is manually finely moved. The manual pulse generator 46 generates a pulse to manually finely operate the X axis, Y axis, Z axis, and C axis. can do. The coordinate display unit 48 is attached to the NC device 42 and has a function of displaying the NC coordinates of the current position of the grinding wheel 28.
[0019]
As shown in FIGS. 3 and 4, the outer peripheral edge of the grinding wheel 28 is a V-shaped blade. In the truing method of this embodiment, the blade surfaces 28a and 28b on both sides of the grinding wheel 28 are ground to precisely shape the blade into a V shape. On the other hand, in the truing grindstone 31, a tapered portion 31a is formed on the outer periphery. FIG. 3 shows a position for truing the inner blade surface 28 a of the grinding wheel 28, and FIG. 4 shows a position for truing the outer blade surface 28 b of the grinding wheel 28.
[0020]
Hereinafter, the contact establishment method in truing according to the present embodiment will be described.
In FIG. 2, a coordinate Xt on the X axis where the grinding wheel 28 is located is determined in advance. Then, the manual pulse generator 46 is operated to send a pulse to the X-axis servo motor 17 so that the table 14 is brought close to the grinding wheel 28 and positioned on the X-axis coordinates of the predetermined grinding wheel 28. At this time, as shown in FIG. 5, the grinding wheel 28 is on the truing wheel 31, and the rotation axis of the grinding wheel 28 and the rotation axis of the truing wheel 31 are orthogonal to each other. Thus, the centers of the grinding wheel 28 and the truing wheel 31 are accurately matched.
[0021]
Next, in FIG. 6A, the truing device 30 is driven to keep the truing grindstone 31 rotating slowly. The spindle motor (not shown) of the spindle head 16 is not energized, and therefore the spindle 25 supported by the hydrostatic bearing is in a state where it can rotate freely.
[0022]
Then, the manual pulse generator 46 is operated to send a pulse to the Z-axis servo motor 22, and the spindle head 16 is slowly lowered until the cutting edge of the grinding wheel 28 contacts the upper surface of the truing wheel 31. When the grinding wheel 28 comes into contact with the upper surface of the truing wheel 31, the grinding wheel 28 that has been stationary until then rotates with the truing wheel 31, so that the Z coordinate of the grinding wheel 28 at this time is read from the coordinate display section 48, Is Zt.
[0023]
Thereafter, the manual pulse generator 46 is operated to raise the spindle head 16 and further retract the column 12 to retract the grinding wheel 28 from the truing wheel 31 as shown in FIG. At this time, the truing grindstone 31 remains rotating, and the grinding grindstone 28 returns to a stationary state when it does not contact the truing grindstone 31.
[0024]
Next, as shown in FIG. 7B, the manual pulse generator 46 is operated to send a pulse to the Z-axis servo motor 22 until the height of the blade is Z1 and the Z coordinate of the grinding wheel 28 becomes Zt + Z1. The grinding wheel 28 is lowered and positioned on this Z coordinate.
[0025]
Then, as shown in FIG. 7C, the manual pulse generator 46 is operated to send a pulse to the Y-axis servo motor 20 to advance the column 12 and to make the grinding wheel 28 approach the truing wheel 31 very slowly. When the blade surface 28a of the cutting edge of the grinding wheel 28 comes into contact with the tapered portion 31a of the truing wheel 31, the grinding wheel 28 that has been stationary until then starts to rotate with the truing wheel 31, so the blade surface 28a of the grinding wheel 28 Can be reliably detected , and the Y coordinate Yt of the contact is determined. Since the rotation centers of the grinding wheel 28 and the truing wheel 31 are already aligned, this contact point can be used as a truing base point . Further, since the contact of the cutting edge of the grinding wheel 28 and the contact of the blade surface 28a are detected by using the accompanying rotation of the truing grindstone 31, it is not necessary to use a special tool stand and is practical. In addition, it is not necessary to look into the grinding wheel 28 until the contact comes out, and work safety can be achieved.
[0026]
As described above , by reading the coordinates (Xt, Yt, Zt + Z1) of the contact point between the grinding wheel 28 and the truing wheel 31 from the coordinate display section 48 of the NC device 42, the position of the contact point can be obtained accurately. Using this contact as a base point Pt for truing grinding, truing is performed as follows.
[0027]
That is, the case where the blade surface 28a inside the grinding wheel 28 is shaped will be described. The contact points between the grinding wheel 28 and the truing wheel are as shown in FIG. This contact is a contact (Xt , Yt, Zt + Z1 ) that has already been obtained . Therefore, in order to move the grinding wheel 28 along the taper portion 31a of the truing wheel 31 along the path passing through this contact point , a machining program is executed so as to perform Y and Z interpolation and to add a driving amount in the Y-axis direction. What is necessary is just to shape and grind the grinding wheel 28 by numerical control based on this processing program. Thereby, high precision truing can be realized.
[0028]
The shaping of the blade surface 28b on the opposite side of the grinding wheel 28 may be performed in the same way as shown in FIG.
[0029]
As described above, the contact establishment method in truing according to the present invention has been described with reference to a preferred embodiment. However, if the grinding wheel is a thin blade, the same is true even if the blade has a single V-shaped or U-shaped cross section. Truing can be performed.
[0030]
【The invention's effect】
As is clear from the above description, according to the present invention, the contact point between the grinding wheel and the truing wheel can be established safely and efficiently, and the grinding wheel can be shaped with high accuracy.
[Brief description of the drawings]
FIG. 1 is a side view showing a grinding machine to which a truing method according to the present invention is applied.
FIG. 2 is a front view of the grinding machine of FIG.
FIG. 3 is an explanatory view showing a contact point between an inner blade surface of a grinding wheel and a truing wheel.
FIG. 4 is an explanatory view showing a contact point between an outer blade surface of a grinding wheel and a truing wheel.
FIG. 5 is a diagram showing a position where the centers of a grinding wheel and a truing wheel are aligned.
FIG. 6 is a view showing a state in which a grinding wheel is in contact with an upper surface of a truing wheel.
FIG. 7 is a diagram showing a procedure for bringing a contact point by bringing a grinding wheel into contact with the outer periphery of a truing wheel.
FIG. 8 is a diagram for explaining how to make contact points between a conventional grinding wheel and a truing wheel.
[Explanation of symbols]
10 bed 12 column 14 table 15 guide 16 spindle head 17 X-axis servo motor 20 Y-axis servo motor 22 Z-axis servo motor 25 spindle 28 grinding wheel 30 truing device 31 truing wheel 31

Claims (2)

In truing for shaping a grinding wheel of a grinding machine having at least three axes of an X axis, a Y axis and a vertical Z axis perpendicular to each other on a horizontal plane , the shaping of the grinding wheel is started. Before, a contact establishment method for accurately obtaining the position of the contact point of the grinding wheel with respect to the truing wheel,
The center of the grinding wheel and the truing wheel are aligned so that the coordinate Xt on the X axis of the grinding wheel matches the coordinate on the X axis of the truing wheel,
When the truing grindstone is rotated, the grinding grindstone is lowered in a rotation-free state, approached to the truing grindstone, and the cutting edge of the grinding grindstone contacts the upper surface of the truing grindstone and rotates together with the truing grindstone Obtain the Z coordinate Zt of the first contact of the grinding wheel ,
Retreating the grinding wheel from the truing grindstone, and lowering the grinding wheel from the retracted position to a position further lowered from the Z coordinate Zt of the first contact by the height Z1 of the blade;
The truing grindstone is rotated to bring the grinding grindstone into a rotation-free state, approaching the truing grindstone from the lowered position in the Y-axis direction, and one of the blade surfaces forming the blade of the grinding grindstone is an outer periphery of the truing grindstone The Y-axis coordinate Yt of the second contact Pt of the grinding wheel when the grinding wheel rotates together with the truing wheel in contact with the portion is determined, and the coordinates (Xt, Yt, Zt + Z1) . A method for establishing a contact in truing. 2. The contact establishment method for truing according to claim 1 , wherein the grinding wheel comprises a thin blade grindstone, and a main shaft to which the thin blade grindstone is attached is supported by an aerostatic bearing at the spindle head.

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