JP2004160583A - Truing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shape a grinding wheel with good accuracy after establishing the contact between the grinding wheel and a truing grinding wheel safely and efficiently. <P>SOLUTION: The grinding wheel 28 and the truing grinding wheel 31 are aligned with each other with the axes thereof intersecting perpendicularly to each other. The truing grinding wheel 31 is rotated, the grinding wheel 28 is put in the state of being free from rotation and made adjacent to the truing grinding wheel 31, and the position where the grinding wheel 28 makes following turn with the truing wheel 31 is searched to find the contact. With reference to the contact, the grinding wheel 28 is located in the truing position, and grinding is performed by the truing grinding wheel 31. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a truing method for shaping a grindstone of a grinding machine, and more particularly to a truing method capable of efficiently and safely bringing out a contact point between a grindstone and a truing grindstone when truing a grindstone such as a thin blade grindstone.
[0002]
[Prior art]
In recent years, NC machines and precision machines have been advanced, and it has become possible to process molds used for molding precision machine parts and to grind glass and plastic materials directly into precision parts. ing.
[0003]
In the grinding machine, as the grinding process is continued, the sharpness of the abrasive grains of the grindstone gradually decreases, or the shape of the grindstone is changed due to wear. Therefore, it is necessary to appropriately perform dressing and truing.
[0004]
Therefore, the truing of a thin blade whetstone, which is a disk-shaped whetstone, will be described with reference to FIG.
The thin blade 2 is mounted on the spindle 6 of the spindle head 5 of the grinding machine, and the outer peripheral blade is shaped using the truing grindstone 3. The truing grindstone 3 is mounted on a truing device 4 arranged on a grinding machine, and rotates on a horizontal plane. While rotating the truing grindstone 3, the blade of the thin blade grindstone 2 is brought into contact with the peripheral edge thereof, and truing is performed.
[0005]
Before starting the truing of the thin blade whetstone 2, it is necessary to adjust the positions of the thin blade whetstone 2 and the truing whetstone 3 first. In the related art, in FIG. 8A, the center positions of both the vertical line passing through the center of the thin blade grindstone 2 are visually measured so that the vertical line passes through the center of the truing grindstone 3, and then shown in FIG. 8B. As described above, the thin blade whetstone 2 was brought into contact with the truing whetstone 3 while the spindle head 5 was being moved by a small amount 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, conventionally, the alignment of the thin blade whetstone 2 and the truing whetstone 3 and the intuition of contacting with the naked eye are relying on the naked eye, so that the center of the thin blade whetstone 2 and the center of the truing whetstone 3 are not exactly aligned. The contact point came out, and the shaping accuracy was poor.
[0007]
Also, in order to bring the thin blade whetstone 2 into contact with the truing whetstone 3 and to make a contact, an operator often works while putting his face inside the cover and looking into the thin blade whetstone 2, thereby improving safety. There was a problem.
[0008]
Therefore, an object of the present invention is to solve the problems of the prior art, and to establish a contact point between a grinding wheel and a truing wheel safely and efficiently, and to perform truing of a grinding wheel with high accuracy. It is to provide a method.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a truing method for shaping a grinding wheel of a grinding machine with a truing wheel arranged on a table, wherein an axis of the grinding wheel and an axis of the truing wheel are provided. The centers of the grinding wheel and the truing wheel are aligned so that the axes are orthogonal to each other, the truing wheel is rotated, and the grinding wheel is brought into a rotation-free state to approach the truing wheel. A contact point is obtained by searching a turning position, the grinding wheel is positioned at the truing position with reference to the contact point, and grinding is performed with the truing wheel.
[0010]
According to the first aspect of the present invention, the stationary grinding wheel starts rotating when it comes into contact with the truing wheel, so that the contact point can be reliably detected. Since the center of the grinding wheel is aligned with the center of the truing wheel, this contact point can be set as the truing position.
[0011]
According to a preferred embodiment of the present invention, the contact point is such that the tip of the grinding wheel is in contact with the upper surface of the truing wheel, and one blade surface forming the blade of the grinding wheel is in contact with the outer peripheral portion of the truing wheel. Contact.
[0012]
The grinding wheel is preferably made of a thin blade, and a spindle to which the thin blade is attached is supported by an aerostatic bearing at a spindle head.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a truing method 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 a 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 mounted on the bed 10 via the guide rail 11 (or a guide formed of a V groove). V-grooves 13a and 13b extending in a direction perpendicular to the direction in which the guide rail 11 extends are formed on the upper surface of the bed 10, and the table 14 can slide using 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 able to move up and down.
[0014]
In this grinding machine, the axis for controlling the feed movement of the table 14 is the X axis, the axis for controlling the feed movement of the column 12 is the Y axis, and the axis for controlling the vertical movement of the spindle head 16 is the Z axis. In this embodiment, in addition to the X axis, the Y axis, and the Z axis, a C axis that controls the turning motion of the turntable 27 disposed 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) mounted on 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 servo motor 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 a Z-axis ball screw 24 extends so as to hang down, and a ball (not shown) attached to the spindle head 16 side. The nut is screwed to 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 where power is not supplied to the spindle motor, the spindle 25 rotates freely. A grinding wheel 28 is held at the tip of the main shaft 25 so as to be sandwiched between the grinding 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 rotating in a plane parallel to the vertical plane.
[0017]
As shown in FIG. 2, a chuck device 29 for fixing a workpiece to be processed is mounted on a swivel 27 installed on the table 14. The turntable 27 has a built-in C-axis turning mechanism driven by a C-axis servomotor (not shown). In addition to the swivel 27, the table 14 is provided with a truing device 30 at a position where it does not interfere with processing. As shown in FIG. 1, the truing device 30 includes a cylindrical truing grindstone 31 and a driving unit 32 that rotationally drives the truing grindstone.
[0018]
In FIG. 1, reference numeral 42 denotes an NC device, and reference numeral 44 drives the X-axis servomotor 17, the Y-axis servomotor 20, and the Z-axis servomotor 22, respectively, based on a command sent from the NC device 42. It is a servo drive circuit. The manual pulse generator 46 is used to manually fine-tune the position of the grinding wheel 28, etc., and generates a pulse to manually perform a fine-motion operation on each of the X, Y, Z, and C axes. 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 blade at the outer peripheral portion 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, the truing grindstone 31 has a tapered portion 31a formed on the outer periphery. FIG. 3 shows a position where the blade surface 28a inside the grinding wheel 28 is trued, and FIG. 4 shows a position where the outside blade surface 28b of the grinding wheel 28 is trued.
[0020]
Hereinafter, the truing method according to the present embodiment will be described.
In FIG. 2, the coordinates on the X axis where the grinding wheel 28 is located are determined in advance. Then, a pulse is sent to the X-axis servo motor 17 by operating the manual pulse generator 46 to bring the table 14 close to the grinding wheel 28 and position the grinding wheel 28 on a predetermined X-axis coordinate. At this time, as shown in FIG. 5, the grinding wheel 28 is on the truing wheel 31, and the center axis of rotation of the grinding wheel 28 and the center axis of rotation of the truing wheel 31 have a positional relationship orthogonal to each other. Thereby, the center of the grinding wheel 28 and the center of the truing wheel 31 are accurately aligned.
[0021]
Next, in FIG. 6A, the truing device 30 is driven to keep the truing grindstone 31 slowly rotating. Power is not supplied to a spindle motor (not shown) of the spindle head 16, and therefore, the spindle 25 supported by the aerostatic bearing is freely rotatable.
[0022]
Then, a pulse is sent to the Z-axis servo motor 22 by operating the manual pulse generator 46, 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 is rotated together with the truing wheel 31, and the Z coordinate of the grinding wheel 28 at this time is read from the coordinate display unit 48. Is Zt.
[0023]
After that, the manual pulse generator 46 is operated to raise the spindle head 16 and further retract the column 12, so that the grinding wheel 28 is retracted from the truing wheel 31 as shown in FIG. At this time, the truing whetstone 31 is kept rotating, and the grinding whetstone 28 returns to a stationary state when it no longer contacts the truing whetstone 31.
[0024]
Next, as shown in FIG. 7B, a pulse is sent to the Z-axis servo motor 22 by operating the manual pulse generator 46 and the height of the blade is set to Z1 until 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, a pulse is sent to the Y-axis servomotor 20 by operating the manual pulse generator 46 to move the column 12 forward, so that the grinding wheel 28 approaches 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 up to that time starts to rotate with the truing wheel 31, so that the blade surface 28a of the grinding wheel 28 Can be reliably detected. Since the rotation centers of the grinding wheel 28 and the truing wheel 31 are already aligned, this contact point can be set as the truing position. Further, since the contact point of the cutting edge of the grinding wheel 28 and the contact point of the blade surface 28a are detected by using the co-rotation of the truing wheel 31, it is not only practical to use a special tool but also practical. In addition, it is not necessary to look into the grinding wheel 28 until the point of contact comes out, so that work safety can be achieved.
[0026]
As described above, after the contact point between the grinding wheel 28 and the truing grindstone 31 is determined, the truing is performed as follows, using the contact point as the starting point of the truing grinding process.
[0027]
That is, the case where the inner blade surface 28a of the grinding wheel 28 is shaped will be described. The contact point between the grinding wheel 28 and the truing wheel is as shown in FIG. Then, using this contact point as a truing base point Pt (Xt, Yt1, zt), Y and Z interpolation are performed to move the grinding wheel 28 on a path along the tapered portion 31a of the truing wheel 31, and Y A machining program may be created so as to provide a drive amount in the axial direction, and the grinding wheel 28 may be shaped by numerical control based on the machining program. As a result, highly accurate 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 manner as shown in FIG.
[0029]
As described above, the truing method according to the present invention has been described with reference to the preferred embodiments. However, if the grinding wheel is a thin blade, the truing is performed in the same manner even if the blade has a V-shaped or U-shaped cross section. It is possible.
[0030]
【The invention's effect】
As is clear from the above description, according to the present invention, it is possible to safely and efficiently establish a contact point between a grinding wheel and a truing wheel, and then accurately shape the grinding wheel.
[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. 1;
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 centers of a grinding wheel and a truing wheel are aligned.
FIG. 6 is a view showing a state where a grinding wheel is brought into contact with an upper surface of a truing wheel.
FIG. 7 is a diagram showing a procedure for bringing a grinding wheel into contact with an outer peripheral portion of a truing wheel to make a contact.
FIG. 8 is a view for explaining a method of setting a contact point 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 Servomotor 20 Y-Axis Servomotor 22 Z-Axis Servomotor 25 Spindle 28 Grinding Wheel 30 Truing Device 31 Truing Wheel

Claims (3)

A truing method of shaping a grinding wheel of a grinding machine with a truing wheel arranged on a table,
The axis of the grinding wheel and the center of the truing wheel are aligned such that the axis of the truing wheel is orthogonal to the axis of the truing wheel,
Rotate the truing wheel, approach the truing wheel in a state where the grinding wheel is free of rotation, seek contact by searching for a position where the grinding wheel co-rotates with the truing wheel,
A truing method comprising: positioning the grinding wheel at the truing position with reference to the contact; and grinding with the truing wheel. The contact point is a contact point at which the cutting edge of the grinding wheel contacts the upper surface of the truing wheel, and a contact point at which one blade surface forming the blade of the grinding wheel contacts the outer peripheral portion of the truing wheel. Item 6. The truing method according to Item 1. 3. The truing method according to claim 2, wherein the grinding wheel is made of a thin blade, and a spindle to which the thin blade is attached is supported by an aerostatic bearing at a spindle head.

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