JP2002028864A - Cnc screw grinding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dress a rotary grinding wheel in the same state as that at the time of screw-grinding for working an object to be ground by the rotary grinding wheel and to perform screw grinding with stably high accuracy. SOLUTION: A dresser stand 7 is disposed on a main shaft slide 2 and a grinding operating surface S for the object to be ground G of the rotary grinding wheel G is dressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CNC screw grinder used for precision screw thread grinding.

[0002]

2. Description of the Related Art Conventionally, as a screw grinder of this type, a bet, a spindle slide slidably disposed on the bet, and a grinding object having a screw disposed opposite to the spindle slide and having a screw are supported. A headstock and a tailstock having a spindle that can be rotationally driven in a state, a grindstone slide slidably disposed in a direction intersecting the sliding direction of the spindle slide, and disposed on the grindstone slide and driven to rotate. A structure having a grinding wheel base having a grinding wheel shaft capable of supporting a rotating grindstone so as to be capable of turning adjustment according to the lead angle of the male screw, and a dresser base having a dresser that is driven to rotate and can dress the rotating grindstone. Are known.

[0003]

However, in the case of the above-mentioned conventional structure, a dresser slide is provided on the above-mentioned grindstone slide so as to be slidable in the same direction as the grindstone slide, and a dresser base is provided on this dresser slide. Is cut into the non-grinding surface on the opposite side of the grinding wheel against the grinding object of the rotating grindstone, so that the dressing is not only possible. On the other hand, the dresser amount and the shape of the dresser change due to the displacement of the dresser slide due to the elongation of the ball screw for slide of the dresser slide and the temperature change, and the position error of the grindstone slide system including the grindstone shaft causes the grinding action surface of the grindstone to grind. Displacement of the position and shape occurs, and the dresser slide displaces with respect to the grinding wheel. The amount of displacement of the grinding wheel head itself and the processing accuracy of the grinding object causes variations in the processing accuracy of the grinding object, which causes irregularities in the shape accuracy of the thread and the effective diameter of the screw, which has the disadvantage that the screw grinding accuracy may be reduced accordingly. ing.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve such inconveniences. According to the present invention, a bet and a bet on the bet are provided. A main spindle slide slidably disposed on the main spindle slide, a headstock having a main spindle that is disposed on the main spindle slide, and is capable of rotationally driving a ground object having a screw, and a direction intersecting the sliding direction of the main spindle slide. A grindstone slide slidably disposed, and a grindstone base having a grindstone shaft disposed on the grindstone slide and capable of supporting a rotatably driven rotary grindstone in a swivel-adjustable manner in accordance with the lead angle of the screw, A dresser base having a dresser that is driven to rotate and that can dress the rotary grindstone. The dresser base is disposed on the main spindle slide, and a grinding action surface of the rotary grindstone against a grinding object is dressed. In CNC screw grinding machine, characterized by being configured to.

According to a second aspect of the present invention, a rotary encoder capable of detecting a rotation angle of the spindle is provided at a rear portion of the headstock.
The invention according to claim 3 is characterized in that the spindle slide and the grinding wheel slide are provided with linear scales capable of detecting respective slide positions.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

FIGS. 1 to 5 show an embodiment of the present invention, in which 1 is a bet, and a main spindle slide 2 is placed on the bet 1.
Are arranged so as to be slidable in the X direction, and the main spindle slide 2 is fed and slid by a main spindle slide servomotor 2a and a ball screw mechanism (not shown).

Reference numeral 3 denotes a headstock, and 4 denotes a tailstock, which is disposed on the main spindle slide 2 so as to face the ground W having a screw N, and a tip end of a spindle 3a of the headstock 3 and a tailstock 4. With the center 4a, the main body is rotationally driven by the spindle servomotor 3b in a double-supported state.

Reference numeral 5 denotes a grinding wheel slide, which is slidably disposed in a Y direction as a direction intersecting the sliding direction of the spindle slide 2. The grinding wheel slide 5 includes a grinding wheel slide servomotor 5a and a ball screw mechanism (not shown). It is configured to slide by cutting.

Reference numeral 6 denotes a grindstone table, and the grindstone slide 5
The grindstone shaft 6a which is disposed above and is rotationally driven is supported,
The rotation axis G ₁ of the rotary grinding wheel G attached to the grinding wheel shaft 6a.
Is provided so as to be rotatable and adjustable in accordance with the lead angle α of the screw N of the grinding object W about the turning axis O of the turning shaft 6c.

In this case, the grindstone table 6 has a cylindrical member 6b fixed on the grindstone slide 5 and a rotating shaft 6 attached to the cylindrical member 6b.
c is rotatably inserted through a bearing 6d, and a bearing member 6e is protruded from a front portion of the revolving shaft 6c.
, The rotating wheel G is mounted on the grinding wheel shaft 6a, and the mounting member 6f is mounted on the rear portion of the turning shaft 6c.
The grinding wheel rotation motor 6g is attached to the
g and a grinding wheel shaft 6a, a belt transmission mechanism 6h is interposed,
Further, a gear 6i is attached to a rear portion of the turning shaft 6c, a turning servomotor 6j is attached to the cylindrical member 6b, and a gear 6k that can mesh with the gear 6i is attached to a main shaft of the turning servomotor 6j. Pivot axis 6c between pivot axis 6c
The rotation fixing mechanism 6m that can fix or allow the rotation of.

Thus, the rotary grinding wheel G is turned by the turning servomotor 6j via the turning shaft 6c in accordance with the lead angle α of the screw N of the grinding object W.

Reference numeral 7 denotes a dresser base, which is disposed on the main spindle slide 2 and has a dresser shaft 7a on the dresser base 7.
A dresser motor (not shown) for rotatably bearing the dresser shaft 7a and driving and rotating the dresser shaft 7a is provided, and a dresser D capable of dressing the grinding surface S of the rotary grindstone G with respect to the grinding object W is attached to the dresser shaft 7a. Make up.

Reference numeral 8 denotes a rotary encoder, which is of an optical type or the like and is attached to a rear portion of the headstock 3.
It is configured to detect the rotation angle of the main shaft 3a.

Reference numerals 9 and 10 denote linear scales, which are of a magnetic type, an optical type or the like, are provided on the spindle slide 2 and the grinding wheel slide 5, and are configured to detect respective slide positions.

Since this embodiment has the above configuration,
At the time of thread grinding, the grinding object W having the screw N is supported by the headstock 3 and the tailstock 4, and the rotating grindstone G is turned according to the lead angle α of the screw N of the grinding object W to grind. Object W
Is rotated, and the grinding wheel G is moved to Y by the grinding wheel slide 5.
And the grinding object W is fed and slid in the X direction by the main spindle slide 2 so that the rotating grindstone G
The grinding operation of the screw N is performed by the grinding operation surface S of the rotary grinding wheel G, and at the time of dressing of the rotary grindstone G, the dresser D is positioned to face the grinding operation surface S of the rotary grinding wheel G by the slide of the main spindle slide 2. , Whetstone slide 5
Then, the rotary grindstone G is cut into the dresser D by sliding, and the dressing of the grinding surface S of the rotary grindstone G is performed by the rotation of the dresser D, the rotation of the rotary grindstone G, and the cutting slide.

Therefore, the dresser table 7 is disposed on the main spindle slide 2 so that the dressing D can dress the grinding action surface S of the rotary grindstone G, so that the dresser slide of the conventional structure can be dispensed with. The structure can be simplified, the cost can be reduced, and the wraparound work due to the setup change to the rear part of the machine is eliminated, so that the workability can be improved and the space can be saved. Unlike the conventional structure in which the non-grinding action surface F is dressed, the dressing can be performed in the same state as in the case of the thread grinding in which the rotating object G is used to machine the grinding object W. Position change of the dresser slide due to the change, the position error of the grinding wheel slide system including the grinding wheel axis, the grinding action surface S The displacement of the dresser slide with respect to the rotating grindstone and the displacement of the grindstone table itself can eliminate the variation in machining accuracy with respect to the grinding object. The diameter can be made uniform, stable and high-precision screw grinding can be performed, and dressing with a special screw shape can be performed using a general-purpose rotary dresser or point dresser.

In this case, since a rotary encoder 8 capable of detecting the rotation angle of the spindle 3a is provided at the rear of the headstock 3, a belt or a gear as a drive transmission element for the spindle 3a and the grinding object W is provided. It is possible to suppress fluctuations in wobbling per rotation of the grinding material W caused by belt elongation, belt pulley run-out, and gear run-out due to a change in the grinding load. In this case, since the linear scales 9 and 10 capable of detecting the respective slide positions are provided on the spindle slide 2 and the whetstone slide 5, respectively, the elongation of the ball screw due to the lead error of each slide ball screw and the temperature change. Positioning error due to lost motion and positioning error due to lost motion It is a control, the thread pitch of the grinding material W, the cumulative thread pitch and the thread effective diameter can be ground with high accuracy.

The present invention is not limited to the above embodiment. For example, a chuck is attached to the spindle 3a of the headstock 3, the tailstock 4 is eliminated, and the ground material W is cantilevered by the chuck. The present invention can also be applied to a screw grinding machine having a structure for supporting and rotating in a state, and the structures of the dresser table 7 and the dresser are appropriately changed and designed.

[0020]

As described above, according to the present invention, the dresser base is disposed on the main shaft slide, and the grinding surface of the rotary grindstone can be dressed by the dresser. Unlike the conventional structure in which the non-grinding action surface is dressed, the rotating grindstone can be dressed in the same state as when screw grinding in which the grindstone is machined by the rotating grindstone. The displacement of the position and shape of the grinding action surface due to the displacement of the dresser slide caused by the elongation and temperature change of the ball screw for the slide and the position error of the grindstone slide system including the grindstone axis can be suppressed. The displacement amount and the displacement of the grinding wheel head itself can eliminate the variation in machining accuracy for the grinding object, and Flip uniformity of shape accuracy and effective thread diameter of the pile can be achieved, it is possible to perform thread grinding stable and accurate.

According to the second aspect of the present invention, since a rotary encoder capable of detecting a rotation angle of the spindle is provided at a rear portion of the headstock, a belt as a drive transmission element for the spindle and the grinding object is provided. Fluctuation of belt grinding, fluctuation of belt pulley, and wobbling of grinding material W per rotation caused by fluctuation of gear due to fluctuation of grinding load of gears and gears. In the invention according to claim 3, since the main spindle slide and the grindstone slide are each provided with a linear scale capable of detecting each slide position, the lead error of each slide ball screw and the lead error can be reduced. Positioning error of ball screw elongation due to temperature change and positioning error due to lost motion can be removed by correction control, and It can be a Rukurozudo control, thread pitch of the grinding product, the cumulative thread pitch and the thread effective diameter can be ground with high accuracy.

As described above, the initial purpose can be sufficiently achieved.

[Brief description of the drawings]

FIG. 1 is an overall plan view of an embodiment of the present invention.

FIG. 2 is a side view of the embodiment of the present invention.

FIG. 3 is a partially enlarged plan view of the embodiment of the present invention.

FIG. 4 is a front view of the embodiment of the present invention.

FIG. 5 is a sectional view of an embodiment of the present invention.

[Explanation of symbols]

 W Grinding material D Dresser N Screw α Lead angle S Grinding surface 1 Bed 2 Spindle slide 3 Spindlehead 3a Spindle 4 Tailstock 5 Grindstone slide 6 Grindstone 6a Grindstone 7 Dresser stand 8 Rotary encoder 9 Linear scale 10 Linear scale

Claims (3)

[Claims] 1. A bed, a spindle slide slidably disposed on the bed, and a headstock having a spindle disposed opposite to the spindle slide and capable of rotationally driving a ground object having a screw, A grindstone slide slidably disposed in a direction intersecting the sliding direction of the main spindle slide, and a rotary grindstone disposed on the grindstone slide and rotationally driven so as to be pivotally adjustable according to the lead angle of the screw. A grindstone table having a grindstone shaft that can be supported, and a dresser table having a dresser that is driven to rotate and that can dress the rotating grindstone. The dresser table is disposed on the spindle slide to grind the rotating grindstone. A CNC screw grinding machine characterized in that a grinding action surface for an object is dressed. 2. The CNC screw grinding machine according to claim 1, wherein a rotary encoder capable of detecting a rotation angle of the spindle is provided at a rear portion of the headstock. 3. The CNC screw grinding machine according to claim 1, wherein a linear scale capable of detecting each slide position is provided on each of the spindle slide and the whetstone slide.