JP2008114352A - Grinding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent fine inclination of a slider by disposing a guide center line of a grinding wheel spindle slide and a driving action line of a feeder on substantially the same straight line and slightly offsetting a rotation center of the grinding wheel spindle from centers of the lines. <P>SOLUTION: A column 13 is stood in an upper part of a base 11, and an upper part base 14 mounted with a driving motor 46 is mounted in an upper part of the column 13. A ball screw 45 integrated to the driving motor 46 is mounted in an upper part of a spindle case 28 slidably fitted in the column 13. In the spindle case 28, a grinding wheel spindle 50 is rotatably mounted by a built-in motor 49. A center of the grinding wheel spindle 50 is the same as a center of the ball screw 45 in a width direction, and the longitudinal direction center is slightly offset to the center of the ball screw 45. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a grinding device, and more particularly, to a grinding device in which a guide center line of a slide member and a driving action center line of a feeding device are provided on substantially the same straight line and prevent the inclination of a grindstone shaft due to pitching and yawing during movement.

Conventionally, since this type of grinding apparatus has a rotation center line, a guide center line, and a driving force acting center line on substantially the same line, the opposing guide surfaces are V-shaped and static pressure pockets. Since the resistances are different, a slight tilt of the slider always occurs, causing stick-slip. For this reason, the direction of the tilting operation (pitching), which is mainly caused by the difference in friction when reversing the vertical movement of the slider, is reversed with respect to the no-load (non-operating) guide center line. For this reason, the position and angle at which the tool and the workpiece come into contact with each other at the end of machining change suddenly and damage the workpiece (for example, see Patent Document 1).
Furthermore, in Patent Document 2, the number of locations for holding the triangular pyramid structure and the guide portion for vertical movement is structurally reduced, and the tool against the reaction force at the time of machining due to a decrease in rigidity due to a decrease in the holding force at the locations. And the rigidity between the workpiece and the workpiece decreases, and the position and angle between the tool and the workpiece change during machining.
Damage to the workpiece. Further, since the tool spindle is structured in a triangular pyramid structure, it becomes difficult to replace the worn tool and to remove the workpiece.
JP-A-8-276358 JP-A-6-155257

  The present invention has been made in order to solve the above-mentioned problems, and the guide center line of the slide member and the drive action center line of the feeding device are arranged on substantially the same straight line, and the center of the grindstone shaft in the front-rear direction. It is an object of the present invention to provide a grinding apparatus that prevents a slight inclination of a slider by slightly offsetting a line from a guide center line and a driving action center line of the slide member.

The present invention has been made to solve the above problems, and the invention according to claim 1 includes a column erected on a base, a slide member slidably inserted into the column,
A rotating table provided on the base and rotating by adsorbing the workpiece, a grindstone fixed to a grindstone spindle facing the rotating table and grinding the workpiece, and rotatably inserted in the slide member. In a grinding apparatus provided with a grindstone driving unit,
The guide surface of the slide member and the center of the drive screw shaft for moving the slide member are the same, the rotation center of the grindstone spindle coincides with the drive screw shaft in the width direction, and the front and rear direction is the drive screw shaft. It is characterized in that it is offset.
According to the present invention, the rotation center of the grindstone spindle is arranged slightly offset from the same straight line between the grindstone shaft guide center line and the driving force acting point of the feeding device, so that the grindstone shaft guide system is always in one direction. By applying the load, it is possible to prevent the slide member from reversing in the tilt direction due to a load change applied to the slide member when the vertical movement is reversed. Furthermore, the influence of the slider tilt on the accuracy of the distance between the tool and the workpiece is reduced by Abbe's principle.

  In the present invention, the rotation center of the grindstone spindle is arranged slightly offset from the same straight line of the grindstone shaft guide center line and the driving force acting point of the feeding device, so that the inclination of the slide member is caused by the Abbe's principle. The effect on the accuracy of the distance between workpieces is reduced.

A preferred embodiment of the tilt grinding apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view of a principal part showing a schematic structure of a grinding apparatus 10 according to an embodiment of the present invention.
In FIG. 1, a grinding table 10 is provided with a rotary table 12 that is rotationally driven by a motor (not shown) in front of an upper portion of a base 11 installed on an installation surface, for example, a floor surface (not shown). A column 13 is erected on the upper rear side of the base 11. An upper base 14 is attached to the top of the column 13.

As shown in FIGS. 2 and 3, the column 13 has a groove 16 (see FIG. 3) having a substantially cross-shaped cross section along the front surface 15 (left surface in FIG. 2). Direction). The groove 16 forms guide surfaces 17 and 18 and guide surfaces 19 and 20 having the same interval in the width direction of the column 13 (left and right direction in FIG. 3), and is a sliding surface orthogonal to these guide surfaces 17 to 20. 21 and 22 and sliding surfaces 23 and 24 are formed. In this case, the distance between the sliding surfaces 25 and 26 defining the width direction (vertical direction in FIG. 3) of the sliding surfaces 21 and 22 and the sliding surfaces 23 and 24 is the same as that of the guiding surfaces 17 and 18 and the guiding surfaces 19 and 20. Wider than the interval. Note that one side of the guide surfaces 17 and 18 is open to the front surface 15, and the other side is adjacent to one side of the sliding surfaces 21 and 23. One side of the guide surfaces 19 and 20 is connected to one side of the sliding surfaces 22 and 24, and the other side of the guide surfaces 19 and 20 is adjacent to both end sides of the guide surface 27. On the other hand, the other sides of the sliding surfaces 21 and 22 and the sliding surfaces 23 and 24 are adjacent to both end sides of the sliding surfaces 25 and 26, respectively.
In the column 13, the center line Y indicates the center in the front-rear direction (the left-right direction in FIG. 3) between the opposing guide surfaces 21 and 22 and the guide surfaces 23 and 24, and the center line Z indicates the guide surface 25 of the column 13. , 26 indicates the center in the width direction (vertical direction in FIG. 3), the intersection of the center lines Y and Z is the center of the guide surface of the spindle case (sliding member) 28, and a ball screw 45 and a drive motor which will be described later 46 is the center of the drive action line.

A spindle case 28 is slidably inserted into the groove 16 of the column 13. As shown in FIGS. 2 and 4, the spindle case 28 includes guide surfaces 17 to 20 of the groove 16, guide surfaces 30 to 33 that engage with the guide surface 27, and a guide surface 40. In this case, the surfaces facing the guide surfaces 30 to 33 and the guide surface 40 of the spindle case 28 and the guide surfaces 17 to 20 and the guide surface 27 of the column 13 do not have a predetermined gap (not shown). I have. On the other hand, the sliding surfaces 21 to 26 of the column 13 come into contact with the sliding surfaces 34 to 39 of the spindle case 28, and the sliding surfaces 34 to 39 slide with the sliding surfaces 21 to 26 as a guide. ing.
Further, between the sliding surface 21 of the column 13 and the sliding surface 34 of the spindle case 28, the sliding surface 34 of the spindle case 28 slidably fitted between the sliding surfaces 21 and 22 of the column 13. , 35 is provided to adjust the gap between the wedges.

Similarly, between the sliding surface 23 of the column 13 and the sliding surface 36 of the spindle case 28, the sliding surface of the spindle case 28 that is slidably inserted between the sliding surfaces 23 and 24 of the column 13. A wedge 43 for adjusting the gap between 36 and 37 is provided.
Further, between the sliding surface 25 of the column 13 and the sliding surface 38 of the spindle case 28, a sliding surface 38 of the spindle case 28 slidably fitted between the guide surfaces 25 and 26 of the column 13, A wedge 44 is provided to adjust the gap between 39. As shown in FIG. 5 (only the wedge 44 is shown in FIG. 5), a pair of the wedges 42 to 44 are provided facing the spindle case 28 in the vertical direction and spaced apart from each other. The guide surface 40 of the spindle case 28 is not in contact with the guide surface 27 of the column 13, and the front surface 41 of the spindle case 28 is exposed from the groove 16 of the column 13 and protrudes from the front surface 15.

  A storage hole 29 is provided in the longitudinal direction (vertical direction in FIG. 1) of the spindle case 28 to store a grindstone spindle 50, which will be described later, and the center in the width direction (vertical direction in FIG. 3) of the grindstone spindle 50 is the center. The center of the storage hole 29 on the line Z in the width direction (vertical direction in FIG. 3) is the same, but the center of the storage hole 29 in the longitudinal direction (vertical direction in FIG. 3) is the longitudinal direction of the guide surface of the spindle case 28. To the spindle case 28 that is applied when the vertical motion is reversed by constantly applying a load in one direction to the grindstone spindle 50 by slightly shifting it toward the front surface 15 side of the column 13 with respect to the center line Y in the left-right direction in FIG. The inclination of the spindle case 28 due to the change in the load is prevented.

  As shown in FIG. 1, a ball screw (driving screw shaft) 45 as a driving screw is fitted into the upper portion of the spindle case 28, and a vertical drive with a gear box attached to the tip of the upper base 14 of the column 13. A motor (hereinafter referred to as a drive motor) 46 is integrally attached, and by driving the drive motor 46, the guide surfaces 35, 37 and 39 of the spindle case 28 and wedges 42 to 44 guide the guide surfaces 21 to 26 of the column 13. And move up and down. Therefore, when the spindle case 28 is slidably inserted into the groove 16 of the column 13, the sliding clearance is adjusted by the wedges 42 to 44, and the horizontal center line of the guide surface of the spindle case 28 is adjusted. The center line X in the left-right direction of the storage hole 29 is shifted to the front surface 15 side of the column 13 with respect to Y, and the inclination of the spindle case 28 due to the load change to the spindle case 28 is prevented.

  A grindstone drive unit 47 is mounted in the storage hole 29. The grindstone driving unit 47 includes a housing 48 fitted in the housing hole 29, a built-in motor 49 attached to the housing 48, and a grindstone that is rotatably supported by the housing 48 and fitted in the built-in motor 49. A spindle 50 and a grindstone 51 detachably attached to the tip of the grindstone spindle 50 are provided. In this case, the centers of the ball screw 45 and the drive motor 46 are the center line Y in the front-rear direction (left-right direction in FIG. 3) of the guide surface of the column 13 and the center line in the width direction (up-down direction in FIG. 3) of the guide surface of the column 13. It will be located at the intersection with Z.

The grinding apparatus 10 according to the present embodiment is basically configured as described above. Next, the operation and effects thereof will be described.
A workpiece 52 is sucked and chucked on the rotary table 12 by a chuck device (not shown) by a control device (not shown), and the rotary table 12 is rotated by an electric motor (not shown). Next, the drive motor 46 is rotated, and the spindle case 28 is moved downward to a predetermined position in FIG. Further, as the spindle case 28 moves, the built-in motor 49 mounted on the housing 48 is driven to rotate the grindstone spindle 50.
The spindle case 28 is further lowered by the control device, the rotating grindstone 51 is brought into contact with the workpiece 52, and the surface of the workpiece 52 is ground. When the surface of the workpiece 52 is ground, the spindle motor 28 is raised to a predetermined position by rotating the drive motor 46 and the ball screw 45 in the reverse direction.

In the grindstone device 10 according to the embodiment of the present invention, as described above, the guide center line of the spindle case 28 having the function of the grindstone shaft slide is the same as the center of the ball screw 45 that is the driving force acting center line of the feeding device. The position, that is, the guide center of the spindle case 28 and the inside of the ball screw 45 are located on the center line Z in both the width direction (up and down direction in FIG. 3) and the front and rear direction (left and right direction).
On the other hand, the center of the grindstone spindle 50 is positioned in the width direction (vertical direction in FIG. 3) on the guide center of the spindle case 28 and the center of the ball screw 45 in the width direction (vertical direction in FIG. 3). And the center line X is slightly constrained so that the guide surface of the spindle case 28 is opposed to the guide center of the spindle case 28 and the center of the ball screw 5, ie, the center line Y. In the space between the surfaces (guide surfaces), they are offset to the opposite column side).
As a result, the guide surface of the spindle case 28 is not a rolling guide in which the constraint of the guide surface becomes a point or line contact, but is a pitching or yawing during movement by averaging the contact portion as a guide in sliding that makes a surface contact. , Rolling changes and the like can be suppressed.

The wedges 41 to 43 may be made of the same kind of material as the column 13 and the spindle case 28, for example, iron. However, if one of the different materials is made of a resin base material impregnated with a lubricant, the contact surface increases. It is preferable from the viewpoints of higher averaging of the contact surface, lowering the surface pressure of the sliding surface, and lowering the frictional resistance that causes the change in inclination.
Adjustment of the clearance of the sliding surface of the spindle case 28, that is, adjustment of the clearance between the sliding surfaces 21, 23 of the column 13 and the sliding surfaces 37, 38 of the spindle case 28, and sliding of the sliding surface 26 of the column 13 and the spindle case 28 Adjustment of the clearance with the moving surface 39 is preferable because it can be adjusted individually from the top and bottom of the spindle case 28 in order to minimize the inclination of the spindle case 28 or the grindstone spindle 50 from the viewpoint of increasing the distance of the contact surface.

In general, when the moving body is fed at a minute speed, a minimum feed amount that can be moved is determined by the minimum command unit of the control system, and therefore, a pseudo minute feed is generated in stepwise step feed. At that time, in the full-closed loop control, since the position is controlled by reading the external scale, it converges to the correct position while repeating overshoot until it stops at the correct position. On the other hand, in the semi-closed loop control (open loop control), a pseudo minute feed is generated in a rounded staircase shape due to delays in each drive transmission system with respect to the motor feed command.
Therefore, in the grinding apparatus 10 according to the embodiment of the present invention, the movement of the spindle case 28 is preferably open loop control or semi-closed loop control in which the moving operation is smooth. Therefore, in full-closed loop control where fine position control is performed during movement and the spindle case 28 is fed at low speed, the overshoot phenomenon during movement and the actual speed of step movement in a very short time are high. Therefore, it is not preferable for the control of the grinding apparatus 10 of the present invention.

Furthermore, in the present invention, the grinding wheel shaft guide center line and the driving force acting center line of the feeding device are arranged on the same straight line, and the rotation center of the remaining grinding wheel shaft is also arranged close to the same straight line. Due to Abbe's principle, the effect of the tilt of the slider on the accuracy of the distance between the tool and the workpiece is reduced.
Further, by adjusting the gap and the tightening allowance individually in the vertical direction, the support distance of the grindstone shaft slide guide surface is increased, and the initial tilt is suppressed, thereby suppressing the occurrence of tilt when the grindstone shaft slide moves up and down.
Also, by increasing the length of the support distance of the grinding wheel shaft slide guide surface, it becomes possible to suppress the surface pressure applied to the sliding portion, reduce the wear of the sliding portion, and deform the sliding portion. Therefore, the inclination of the grindstone shaft slide is also reduced.

It is a side view showing a schematic structure of a grinding device concerning an embodiment of the invention. It is the II-II sectional view taken on the line of FIG. FIG. 3 is a detailed view of a groove formed in the column of FIG. 2. FIG. 3 is a detailed external view of the spindle case of FIG. 2. It is a perspective view showing a schematic structure of a grinding device concerning an embodiment of the invention. It is a perspective view showing a schematic structure of a grinding device concerning an embodiment of the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Grinding device 11 Base 12 Rotary table 13 Column 16 Groove 17-20 Guide surface 21-26 Sliding surface 28 Spindle case 29 Storage hole 30-33 Guide surface 34-39 Sliding surface 42-44 Wedge 45 Ball screw 46 Gear box Upper and lower drive motor 47 Grinding wheel drive section 48 Housing 49 Built-in motor 50 Grinding wheel spindle 51 Grinding wheel 52 Workpiece

Claims (1)

A column erected on the base, a slide member slidably inserted into the column,
A rotating table provided on the base and rotating by adsorbing the workpiece, a grindstone fixed to a grindstone spindle facing the rotating table and grinding the workpiece, and rotatably inserted in the slide member. In a grinding apparatus provided with a grindstone driving unit,
The guide surface of the slide member and the center of the drive screw shaft for moving the slide member are the same, the rotation center of the grindstone spindle coincides with the drive screw shaft in the width direction, and the front and rear direction is the drive screw shaft. Grinding apparatus characterized by being offset with respect to.

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