JPH06270058A - Grinding device - Google Patents

Abstract

PURPOSE:To reduce surface roughness of a work surface, and lengthen the service life of a grinding wheel by constituting a grinding device of a polishing grinding wheel, a work material loading stand and a feed mechanism to move these relatively, and providing a reversing mechanism to move the grinding wheel reversely. CONSTITUTION:This grinding device installed on the tip of a spindle of a machine tool 2 such as an NC vertical milling machine has a rotary spindle 12 where a grinding wheel 13 is installed on the tip, and reversal motion is given in the rotating direction by a stepping motor 14. A reversal angle and reversal speed and the like of this reversal motion are controlled by a control device 15. A work material 16 is loaded on a feed table 17 of the machine tool, and feed motion is given in the optional direction, and cutting is given by the machine tool 2. According to its necessity, an ultrasonic vibration system is arranged to vibrate the grinding wheel 13 by an ultrasonic wave. Since the reversal motion is given in this way, a work surface can be ground from the various directions, so that surface roughness can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding device for smoothing the surface of metal materials, glass materials, ceramic materials and the like.

[0002]

2. Description of the Related Art In a conventional grinding apparatus, a grinding wheel performs a relatively high-speed rotary motion for the purpose of removing a material and a relatively low-speed feed motion for the purpose of creating a shape. Therefore, the relative movement direction between the grindstone and the workpiece is limited to about 1 or 2 directions, and grinding marks having a directionality corresponding thereto are formed. Since these grinding marks have irregularities corresponding to the protrusion height of the abrasive grains on the surface of the grinding wheel, the surface roughness of the machined surface was large.

Further, due to the rotational movement, the abrasive grains on the surface of the grinding grindstone always perform the material removing action in substantially the same direction, while the grinding work is performed at almost the same location of the abrasive grains.
The processing load acted from almost one direction. The abrasive movement of the abrasive grain cutting edge rapidly progresses due to the rotational movement, so that the life of the grindstone is relatively short.

[0004]

Since the relative movement direction between the grindstone and the work piece is limited in the conventional grinding apparatus as described above, the grinding surface has the movement direction between the grindstone and the work piece. Grinding marks having irregularities approximately equal to the protruding height of the abrasive grains were formed, and the surface roughness of the machined surface was relatively large. Therefore, there has been a problem that in order to improve the surface roughness, a grinding wheel formed of abrasive grains having a small grain size must be used at the expense of processing efficiency. In this case, even if ultrasonic vibration is applied to the grinding wheel, the grinding resistance between the grinding wheel and the workpiece can be decreased to increase the processing amount, but the surface roughness of the processed surface is the same for the same reason. It didn't get smaller.

Further, in the conventional grinding machine, since the abrasive grains on the surface of the grinding wheel always remove the work piece from a limited direction, the machining load on the abrasive grains is concentrated in one place, and the abrasive grains are damaged. There is also a problem that it progresses rapidly and the life of the grindstone is short. The object of the present invention is to solve these problems.

[0006]

SUMMARY OF THE INVENTION The present invention is, firstly, a grinding device comprising a grinding wheel, a workpiece mounting table, and a feed mechanism for relatively moving the grinding wheel and the workpiece.
There is provided a grinding device (hereinafter referred to as a first invention) provided with a reversing motion mechanism for reversing the grinding wheel. Secondly, the grinding apparatus of the first invention is provided with an ultrasonic vibration system for ultrasonically vibrating the grinding wheel (hereinafter referred to as the second invention).

[0007]

In the present invention, the grinding wheel is connected to the rotary spindle or the tip of the ultrasonic vibration system, and the grinding wheel is moved in reverse around the rotary spindle or the central axis of the ultrasonic vibration system. The reversing motion in the present invention means that the grinding wheel does not rotate only in one direction but reverses the rotation direction within a range sandwiched by a predetermined angle.

At this time, the reversing angle and the reversing speed of the grinding wheel are generally input to the control device in advance, and the reversing motion is controlled by controlling the stepping motor, the servo motor or the like in accordance with the command at the time of processing. give.
At the same time, a structure is provided which has a feed mechanism for moving the grinding wheel in the direction parallel to the rotary spindle or the central axis of the ultrasonic vibration system. This may be done by providing a linear motion mechanism etc. in the main body of the machine and making it reciprocate with a motor etc. with a stroke and movement speed input in advance, or by installing this machine on a machine tool such as a milling machine, Alternatively, the table may be fed to the table.

In order to reduce the surface roughness of the machined surface,
It suffices if the machined surface is ground in many directions. This is because, when a constant cutting amount is given, grinding marks matching the cutting amount are formed without intersecting with each other depending on the processing direction, and the height of the grinding marks is low. Because it will be. According to the present invention, the processing direction becomes two directions by reversing the movement of the grinding wheel. Further, at the same time as the reversing movement, by a feed mechanism that relatively moves the grinding wheel and the workpiece, the reversing direction of the grinding wheel and the moving direction of the workpiece are orthogonal to each other,
The machined surface of the workpiece is ground from various directions,
The surface roughness becomes smaller.

FIG. 3 is a schematic diagram showing the principle of the present invention. 1 of the surface of the grinding wheel that is reversing as shown by arrow S in an arbitrary cross section that is substantially orthogonal to the axis of rotation of the grinding wheel
One abrasive grain 35 reciprocates in an arc portion sandwiched by the reversal angle θ of the grinding wheel. On the other hand, the workpiece 37 reciprocates in the direction of arrow T by the feed mechanism. As a result, the locus drawn by the abrasive grains 35 is as indicated by 36 in the figure.

FIG. 4 is a projection of the locus 36 shown in FIG. 3 on a plane. It can be seen that the abrasive grains 35 grind from various directions on the machined surface. The locus varies depending on the position of the abrasive grains on the arc. Further, in reality, on the arc, there are a plurality of abrasive grains at the contact portion between the abrasive grains 35 and the workpiece 37, and further there are also a plurality of abrasive grains at each cross section along the rotation axis. During the processing, the workpiece 37 is ground from a specific direction for each abrasive grain. As a result, the number of directions in which the machined surface is ground is increased, and the surface roughness of the machined surface is reduced for the reasons described above.

Further, similarly, since the abrasive grains of the grinding stone are ground from multiple directions, the grinding load on the abrasive grains is dispersed without being concentrated at one place. Therefore, abrasion of the abrasive grains is suppressed, and the life of the grinding wheel can be extended.

[0013]

Embodiment 1 (Example of First Invention) FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention. This device is attached to the tip of the main spindle of a machine tool 2 such as an NC vertical milling machine. The grinding wheel 13 is connected to the tip of the rotary spindle 12, and is given a reversing motion in the rotational direction by a stepping motor 14. Machining parameters such as the reversing angle and the reversing speed of the reversing motion are input to the control device 15 such as a personal computer in advance, and the stepping motor 14 is controlled by the control device 15.

The workpiece 16 is a feed table 17 of a machine tool.
It is placed on top and given a feed motion in any direction. A notch is provided by the machine tool 2 during the grinding process.

[0015]

Embodiment 2 (Example of Second Invention) FIG. 2 is a schematic sectional view showing a second embodiment of the present invention. The grinding wheel 23 is coupled to the tip of an ultrasonic vibration system composed of the ultrasonic vibrator 21 and the horn 22. The ultrasonic vibration system is fixed to the inner cylinder 25 by a fixing flange 24 formed on the horn 22, and the inner cylinder 25 is further supported by an outer cylinder 27 by bearings 26.

A rotary connector 28 provided at the rear end of the inner cylinder 25 supplies a high frequency current from an ultrasonic oscillator 29 to the ultrasonic vibrator 21. The ultrasonic vibrator 21 converts the electric vibration into mechanical vibration and transmits the mechanical vibration to the horn 22, and the horn 22 expands the amplitude of the mechanical vibration and transmits the mechanical vibration to the grinding wheel 23, which vibrates the grinding wheel 23 ultrasonically. Further, a stepping motor 30 that performs a reversing motion is attached to the outer cylinder 27, and the reversing motion is transmitted to the inner cylinder 25 by a timing belt 31.

This device is attached to a machine tool (not shown) as in the first embodiment, and the reversing motion and setting of the cut are performed by the machine tool. With the above configuration, the grinding wheel 23 can simultaneously perform ultrasonic vibration, reversal movement in the rotation direction, and feed movement in the axial direction. In this device, it is possible to reduce the grinding resistance on the surface of the workpiece by applying ultrasonic vibration, and it is possible to perform the grinding process with high efficiency.

In each of the above-described embodiments, the following methods can be considered as the method of reversing the grinding wheel. As a first method, the grinding wheel is reversed on the same circumference at a predetermined reversal angle. In addition, as a second method, after a predetermined angle (hereinafter referred to as a lead angle) is rotated in one direction during the reversing motion, an angle different from the lead angle (hereinafter, referred to as a lead angle).
This is called the return angle) and is rotated in the opposite direction. These are performed by changing the settings of the control device that controls, for example, a stepping motor.

In the first method, the grinding wheel grinds only on the surface within the range determined by the reversal angle, but in the second method, the grinding wheel rotates every time the reversing movement is performed, and therefore the grinding wheel rotates. There is an advantage that the entire circumference of the grinding wheel can be used. In addition,
As the reversing mechanism in the present invention, a method of controlling the stepping motor or the servomotor shown in the first and second embodiments so that the motor itself inverts the grinding wheel, and a rotational movement of the motor is linked by the grinding wheel. It can be considered as a method of converting into a reversing motion of. FIG. 5 is a front view showing a reversing mechanism using the link. Motor 5
A crank 53 is attached to the rotary shaft of No. 5, and one end of a link 54 is attached to the crank 53 at a position deviated from the rotary shaft. The other end of the link 54 is the inner cylinder 5
It is attached to 6. In the above configuration, the motor 5
The rotational movement of 5 is converted into a reversing movement by the link 54 and transmitted to the inner cylinder 52, and the inner cylinder 52 and the grinding wheel 51 provided on the inner cylinder 52 are reversed.

[0020]

As described above, according to the first aspect of the present invention, the surface roughness of the machined surface is reduced and the life of the grinding wheel is extended. In the second invention,
In addition to the effects of the first aspect of the invention, the amount of processing increases due to the high efficiency of grinding.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment and showing a case where a grinding apparatus according to the present invention is mounted on a machine tool.

FIG. 2 is a schematic sectional view of a grinding apparatus having an ultrasonic vibration system according to a second embodiment.

FIG. 3 is a diagram showing a locus of movement of one abrasive grain on the surface of the grinding wheel when the rotating direction of the grinding wheel and the moving direction of the workpiece are orthogonal to each other in the present invention.

FIG. 4 is a diagram showing a case where the locus shown in FIG. 3 is projected on a plane.

FIG. 5 is a front view showing a reversing mechanism using a link.

[Explanation of symbols for main parts]

 2 Machine Tool 12 Rotating Spindle 13 Grinding Wheel 14 Stepping Motor 15 Control Device 16 Workpiece 17 Feed Table 20 Machine Tool 21 Ultrasonic Transducer 22 Horn 23 Grinding Wheel 24 Fixing Flange 25 Inner Cylinder 26 Bearing 27 Outer Cylinder 28 Rotary Connector 29 Ultrasonic oscillator 30 Stepping motor 31 Timing belt 51 Grinding wheel 52 Inner cylinder 53 Crank 54 Link 55 Motor

Claims (2)

[Claims] 1. A grinding device comprising a grinding wheel, a work table, and a feed mechanism for relatively moving the grinding wheel and the workpiece, wherein a reversing mechanism for reversing the grinding wheel is provided. And grinding equipment. 2. The grinding apparatus according to claim 1, further comprising an ultrasonic vibration system for ultrasonically vibrating the grinding wheel.