JP2000005908A - Holder, processing device and processing method - Google Patents

Abstract

(57) [Problem] To provide a holder, a processing apparatus, and a processing method capable of improving processing accuracy without deteriorating production efficiency. A lathe apparatus to which the present invention is applied includes a work material holder (3) capable of applying a desired stress to a work material (1) such as a video drum being processed using a piezoelectric element (6).
And a stress control means for driving the piezoelectric element 6 so as to apply a desired stress to the work material 1 in synchronization with the position information of the cutting tool 10 or the work material 1. According to the present invention, since the piezoelectric element 6 applies a desired stress to the work material 1 during the work of cutting the work material, the deformation of the work material due to the cutting stress or the centrifugal force is corrected, and the processing with higher precision is performed. It becomes possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a holder, a processing apparatus, and a processing method, and more particularly, to a holder, a processing apparatus, and a processing method capable of improving a processing accuracy by applying a desired stress to a work material. Things.

[0002]

2. Description of the Related Art In recent years, there has been an increase in the number of cut parts requiring extremely high processing accuracy.
Lightening (thinning) tends to reduce the rigidity of components. Further, in machining by turning, it is necessary to increase the cutting speed in order to obtain high precision, and when the machining diameter of a part is reduced, it is necessary to further increase the rotation speed of the work material. Therefore,
The centrifugal force applied to the work material tends to increase. In addition,
Related conventional examples include JP-A-59-227304 and JP-A-6-1
55242, JP-A-6-70601 and JP-A-8-25101.

[0003]

In the conventional cutting apparatus as described above, the rigidity of the component itself is low, and when the rotation speed of the work material is increased, elastic deformation due to centrifugal force cannot be ignored. However, there is a problem that required processing accuracy cannot be obtained. Further, due to the function of the part, when the shape is asymmetrical with respect to the rotation axis, there is a case where necessary processing accuracy cannot be obtained due to non-uniform deformation, particularly due to cutting stress or centrifugal force. . FIG. 3 shows a fan-shaped hole 1
1 is a perspective view illustrating a configuration of a thin drum 1 having a thin drum 1. In the case of a perforated drum having such an asymmetric shape with respect to the rotation axis, the rigidity of the portion having the hole 11 is low, and the drum 1
When the side surface is cut, deformation due to cutting stress increases in the vicinity of the hole 11. Therefore, after cutting,
Roundness deteriorates only in that part.

FIG. 4 is an explanatory diagram showing an example of deterioration of the roundness of the drum as shown in FIG. Although exaggerated in FIG. 4, in the vicinity of the hole 11, the cutting surface is elastically deformed more inward due to the cutting stress, and the cutting becomes insufficient by that amount. There was a problem that only that portion swelled.

In order to perform the cutting work, the work material must be held and fixed by some method. However, in the case of a work material having low rigidity as described above, the work force is required for the cutting force. When a sufficient holding force is applied, the effect of the elastic deformation of the work material due to the holding force affects the accuracy of the machined surface, and a required accuracy cannot be obtained. For the same reason, even if the accuracy can be ensured, the holding method becomes complicated, and it takes time to attach and detach the work material. Alternatively, there is a problem in that production efficiency is deteriorated, for example, adjustment of the holder is required, and the switching time and maintenance of the production model are increased. An object of the present invention is to provide a holder, a processing apparatus, and a processing method capable of solving the above-described problems of the related art and improving processing accuracy without deteriorating production efficiency.

[0006]

SUMMARY OF THE INVENTION The present invention is characterized by a holder for a work material provided with a holding means for applying a desired stress to a work material being processed by using a piezoelectric element. There is also a feature in a stress control unit that drives the piezoelectric element so as to apply a desired stress to a work material in synchronization with position information of a tool or a work material. According to the present invention, the piezoelectric element applies a desired stress to the work material during the work of cutting the work material, so that the deformation of the work material due to the cutting stress or the centrifugal force is corrected, and more accurate processing can be performed. Become.

[0007]

Embodiments of the present invention will be described below in detail. In this embodiment, outer diameter lathe processing of a video drum will be described as an example. FIG. 1 is a cross-sectional view showing a configuration of a main shaft of a lathe device provided with a holder to which the present invention is applied. Note that the upper half of FIG. 1 shows a cross section of the sub nail 3, and the lower half of FIG. 1 shows a cross section of the main nail 2. FIG.
It is sectional drawing in -A part.

When a workpiece 1 such as a video drum having an asymmetrical shape with respect to a rotation axis is machined using an NC (numerical control) lathe, the back side of the video drum 1 whose circularity is deteriorated is
It is held by a chuck having a main claw 2 and a sub-claw 3, and the outer diameter is cut by a blade 10. The main claw 2 is fixed to a master jaw 5 of a three-jaw chuck, and the sub-claw 3 is fixed to a three-jaw chuck main body (main shaft of a lathe) 5.

A plurality of piezoelectric elements 6 (hatched portions) which expand and contract in the radial direction in synchronization with a signal from the NC device are fixed to the outer side of the sub-claw 3, and the sub-claws which contact the inner side surface of the drum are provided outside thereof. The movable part 7 is mounted. The expansion and contraction of the piezoelectric element 6 applies a desired radial stress to the workpiece 1 in accordance with the rotation angle of the main shaft of the lathe.

Similar to the main claw 2, the sub-claw 3 is co-processed such that the work chucking surface of the sub-claw movable section 7 becomes a perfect circle after being attached to the lathe main shaft 5. The position of the sub-claw 3 needs to correspond to the point where the circularity of the video drum 1 as a work material is deteriorated. Therefore, when the drum 1 is mounted on the main shaft 4, the main claw 2 is expanded after the position is adjusted. Fix and hold. Since the main shaft 5 is rotating, a control signal of the piezoelectric element 6 is transmitted to a piezoelectric element driving circuit mounted on the main shaft via a signal transmission mechanism to a rotating body (not shown), and a driving signal of the element is transmitted to a driving line. 8 to the piezoelectric element 6.

FIG. 6 is a block diagram showing the configuration of the entire lathe to which the present invention is applied. In FIG. 6, the main claw 2 and the sub-claw movable section 7 are omitted. Numerical control (N
C) The device 40 outputs cutting control information to the lathe device 20. The tool path control circuit 30 controls the position control device 22 according to the input position and movement information of the cutting tool 10 to move the cutting tool 10 to a desired position. The rotation control circuit 32 controls the driving device 21 including a motor or the like so that the main shaft 5 rotates at a desired rotation speed and phase.

The control signal generation circuit 31 includes a numerical control device 4
For example, a drive control signal which is a digital signal representing a drive voltage of each piezoelectric element 6 is generated based on 0 or the rotation phase information of the main shaft input from the rotation control device 32. This control signal is mounted on the main shaft 5 through a signal transmission mechanism to a rotating body using a rotary transformer or the like used in, for example, an infrared signal transmission circuit, a radio signal transmission circuit, or a video tape recorder. It is transmitted to the piezoelectric element drive circuit 9. Power is supplied by, for example, a rotary transformer, a cylindrical electrode, a brush, or the like.
The element drive circuit 9 includes, for example, a D / A converter, and generates a drive voltage signal for each piezoelectric element 6 based on the transmitted digital control signal.

Next, the operation will be described. First, video drum 1
Are fixed by the main claw 2 of the main shaft 5. At this time, the video drum is mounted such that the movable portion 7 of the sub-claw 3 comes into contact with the drum side surface at the center of the hole 11 of the video drum.

Next, under the control of the numerical controller 40, the main shaft 5 is rotated at a predetermined rotation speed and phase, and the cutting tool 10 is moved along a predetermined trajectory for cutting. At this time, in synchronization with the rotation phase of the main shaft 5, a driving voltage is applied to the piezoelectric element 6 to expand the piezoelectric element 6 so that the deformation of the cutting tool 10 due to the cutting stress becomes the same as the other parts. Stress is applied to the portion of the drum 1 where the circularity is deteriorated from the inside. The drive voltage waveform to each piezoelectric element 6 is experimentally determined so that the roundness of the processed drum 1 is optimized.

FIG. 5 is an explanatory diagram showing an example of cutting control in the main spindle direction of the lathe. For example, when the three piezoelectric elements 6 provided on the sub-claw 3 are driven by the same drive signal, the roundness may be different in the axial direction unless the rigidity at an arbitrary position in the axial direction is uniform. There is. Therefore, the cutting tool 10
When moving in the axial direction to perform machining, the cylindricity is controlled by driving a plurality of piezoelectric elements 6 arranged in the axial direction with different drive voltages in synchronization with the cutting position in the axial direction. Can be done. In FIG. 5, the size of the arrow indicates the pressing force of the piezoelectric element 6, and only the piezoelectric element close to the cut portion may be driven as shown in FIG. The piezoelectric element may be driven. Further, all the piezoelectric elements may be driven with the optimum voltages.

With respect to the deterioration of the processing accuracy due to the wear and deformation of the movable portion 7, if the control information of the NC is corrected within the expansion and contraction width of the piezoelectric element, a longer service life than that of a normal fixed claw can be obtained. . In addition, since the sub-claw movable portion 7 is fixed on the sub-claw fixing portion, when the movable portion 7 processed outside the machine is replaced, only the signal given to the piezoelectric element 6 is controlled, thereby achieving the conventional accuracy. Can be restored, so that the time for setup change and maintenance can be reduced.
Further, by forming the portion of the sub-claw movable portion 7 that comes into contact with the workpiece in a dot-like shape instead of a negative shape, it is also possible to intentionally work into an irregular shape.

While the embodiment of the present invention has been disclosed above, the present invention may have the following modifications. In the embodiment, the example in which the piezoelectric element is provided in the sub nail is disclosed, but the piezoelectric element may be built in the main nail. In this case, the work may be held by moving the main claw as in the related art, or the work may be held / released by expansion and contraction of the piezoelectric element. In the embodiment, three main claws and two sub claws are disclosed. However, the numbers and positions of the main claws and the sub claws are arbitrary. May be selected and designed according to the position and the number of.

In the embodiment, the example in which the workpiece is held by the main claws and the sub claws from the inside of the drum and the outer periphery is turned is disclosed. For example, the outside of the drum is held by the main claws and the sub claws, and the inside is turned. The present invention can also be applied to turning. In this case, it is possible to correct elastic deformation due to centrifugal force in addition to deformation due to cutting stress. In turning and milling, the flatness of the end face or the XY plane can be controlled by employing the same mechanism as the sub-claw for the stopper of the workpiece.

In the embodiment, an example in which the present invention is applied to a lathe apparatus is disclosed. However, the present invention can be applied to any processing apparatus such as a milling machine which holds a workpiece and performs cutting processing, in addition to a lathe. is there.

[0020]

As described above, in the present invention,
A holding means for applying a desired stress to the work material being processed using the piezoelectric element is provided, and the piezoelectric element is applied so as to apply a desired stress to the work material in synchronization with the position information of the cutting tool or the work material. Since the drive is performed, the deformation of the work material due to the cutting stress or the centrifugal force is corrected at the time of the work of cutting the work material, so that there is an effect that the processing can be performed with higher accuracy. Further, since there is no need for mechanical adjustment of the sub-claw, the time for attaching and detaching the work material, the time for switching between models, and the like are shortened, and there is an effect that the production efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a main shaft of a lathe apparatus to which the present invention is applied.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a perspective view showing a configuration of a thin drum 1 having a fan-shaped hole 11;

FIG. 4 is an explanatory view showing an example of deterioration of the roundness of the drum shown in FIG. 3;

FIG. 5 is an explanatory diagram showing an example of cutting control in the main spindle direction of a lathe.

FIG. 6 is a block diagram showing the overall configuration of a lathe apparatus to which the present invention is applied.

[Explanation of symbols]

1 ... Workpiece (video drum), 2 ... Main nail, 3 ... Secondary nail, 4
... Spindle, 5 ... Master jaw, 6 ... Piezoelectric element, 7 ... Sub-claw movable part, 8 ... Connection line, 9 ... Piezoelectric element drive circuit, 10 ... Cutting tool, 11 ... Hole, 20 ... Lathe device, 21 ... Drive device ,
22 position control device, 30 tool path control circuit, 31
... Control signal generation circuit, 32 ... Rotation control circuit, 40 ... Numerical control device

Claims (3)

[Claims] 1. A holder for a work material comprising a stress applying means for applying a desired stress to the work material being processed. 2. A work material holder provided with a stress applying means for applying a desired stress to a work material being processed by using a piezoelectric element, and in synchronization with positional information of a cutting tool or a work material. A processing apparatus comprising: stress control means for driving the piezoelectric element so as to apply a desired stress to a work material. 3. A method for applying a desired stress to a work material being machined in synchronization with a first step of cutting the work material held by the holding means and the positional information of the cutting tool or the work material. And a second step of driving the piezoelectric element provided in the holding means at the same time.