JPH0929579A - Device for processing drum in rotary head device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for processing a drum in a rotary head device, which can process micro-protrusions having such a shape that can reduce impact errors. SOLUTION: A device for processing a drum in a rotary head device, comprises a rotary means 14 for gripping and rotating 8 drum 11 in a rotary head device, moving means 20, 22 for gripping a tool 15 and for moving the same in both axial and radial directions of the drum 11, the rotary means 14 and the moving means 20, 22 being operated in synchronization with each other so as to process the drum 11 with the tool 15, and a micromovement means 32 for slightly moving the tool 15 in the radial direction of the drum 11 in synchronization with the rotary means 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing device for processing a drum of a rotary head device used as a work for recording a signal on a magnetic tape or reproducing a signal from the magnetic tape.

[0002]

2. Description of the Related Art For example, in a rotary head device of a video tape recorder, a magnetic tape runs obliquely with respect to a rotary drum (upper drum) and a fixed drum (lower drum) which are rotated by a drive motor. A magnetic head is built in the rotary drum and the fixed drum, and the magnetic head scans the magnetic tape in an oblique direction. By this operation, a desired video signal or audio signal is recorded on the magnetic tape from the magnetic head or reproduced from the magnetic tape via the magnetic head. A lead is formed on the peripheral side surface of the fixed drum to regulate the running of the lower edge of the magnetic tape. Such leads are
For example, it is formed by a cam lapping process in which a tool is moved according to the shape of a copying surface formed in advance on the cam.

Further, the magnetic head on the peripheral side surface of the fixed drum is locally attached to the magnetic tape at a position where the magnetic head comes into contact with the magnetic tape (hereinafter referred to as a rush end) and a position where the magnetic head ends contact with the magnetic tape (hereinafter referred to as a release end). There are some that are formed with minute projections that give tension to the. The minute projections serve to reduce a phenomenon in which the magnetic tape vibrates due to a sudden change in the contact surface pressure of the magnetic head at the entry and exit ends, that is, an impact error. Therefore, if there are no small protrusions,
An impact error is likely to occur, for example, during playback of a video signal, jitter occurs in the playback signal to deteriorate image quality, or magnetic tape sticks to the peripheral side surface of the fixed drum to cause hunting. May cut the magnetic tape. The minute protrusions described above can be formed by, for example, thinning the inside of the tape running surface of the fixed drum and plastically bulging and deforming this portion by applying an external force with a punch or the like. However, this processing has a drawback that it is difficult to improve the processing accuracy and to process it into a desired shape. Therefore, the fine protrusions are usually formed by cutting with a lathe.

FIG. 7 is a plan view showing an example of a numerically controlled lathe which is an example of a drum processing device of a conventional rotary head device. The radial direction of the drum is the X direction and the axial direction of the drum is the Z direction. This numerically controlled lathe 10 has a chuck 12 for holding a fixed drum 11, and a spindle motor 13
A first slider 18 that has a main shaft 14 rotated by a tool and a tool rest 16 that holds a tool 15, and is finely moved in the Z direction by a first motor 17, and the first slider 18 is mounted. A second slider 20 that is moved in the X direction by a motor 19 and a third slider 22 that mounts the second slider 20 and that is moved in the Z direction by a third motor 21 are provided. Numerical control lathe 10 having such a configuration
When the minute protrusions are formed by the cutting process by using, the rotation of the main shaft 14 and the movement of the first slider 18 are synchronized, and a perspective view of the fixed drum 11 of FIG. 8 and the fixed drum 11 of FIG.
The tape running surface 2 and the leads 3 are formed by cutting so as to leave the portions 1 where the minute protrusions having the shape shown in FIG. To form a minute protrusion.

[0005]

However, the second slider 20, which is the moving means in the X direction of the conventional numerically controlled lathe 10 described above, has the tool 15, the tool rest 16, the first motor 17, and the first slider 20 mounted thereon. Since the slider 18 and the like are mounted, the slider 18 is heavy, and the inertia in the X direction becomes large. For this reason, the responsiveness of the movement control in the X direction is poor, and therefore a minute protrusion having a shape that further reduces impact error, for example, is formed on the running surface of the magnetic tape as shown in FIG. In the case of performing the processing for forming the minute protrusions having a smooth curved surface shape, there is a drawback that the rotation speed of the spindle 14 must be reduced so that the rotation of the spindle 14 and the movement of the second slider 20 can be synchronized. .

The present invention has been made to solve the above problems, and is a drum processing apparatus for a rotary head apparatus capable of processing a minute projection having a shape that further reduces impact errors at high speed and with high accuracy. Is intended to provide.

[0007]

SUMMARY OF THE INVENTION In the present invention, the above object is to provide a rotating means for gripping and rotating a drum of a rotary head device, and a tool for gripping and moving the drum in an axial direction and a radial direction of the drum. A drum processing device of a rotary head device for processing the drum with the tool by synchronizing the rotating means and the moving means with each other, in a radial direction of the drum in synchronization with the rotating means. This is achieved by providing a minute moving means for minutely moving to.

According to the above construction, the minute movement of the tool in the radial direction of the drum can be synchronized with the rotation of the drum, so that the fine machining on the peripheral side surface of the drum can be performed with high precision.

[0009]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Although the embodiments described below are preferred specific examples of the present invention, various technically preferable limitations are given. However, the scope of the present invention is not limited to the following description. It is not limited to these forms unless otherwise stated.

FIG. 1 is a plan view showing an embodiment of a numerically controlled lathe which is an embodiment of a drum processing device of a rotary head device according to the present invention. This numerically controlled lathe 30 includes a fixed drum 1
1 has a chuck 12 for gripping 1 and a spindle 14 rotated by a spindle motor 13 and a tool rest 3 for gripping a tool 15.
A first slider 18 that has a first motor 18 and is minutely moved in the Z direction by a first motor 17; and a second slider 20 that mounts the first slider 18 and that is moved in the X direction by a second motor 19. A third slider 22 is provided on which the second slider 20 is placed and which is moved in the Z direction by a third motor 21. On the tool rest 31, a minute moving means 32 for minutely moving the tool 15 in the X direction is placed and fixed. The control unit 40 of the minute moving means 32 is provided in the control device of the numerically controlled lathe 30.

The control section 40 counts the Z-phase, A-phase and B-phase pulse signals from the pulse coder 33 attached to the spindle motor 13 to detect the rotation angle of the spindle 14, and the preset angle is preset. A rotation angle detection unit 41 that outputs a minute movement signal when a predetermined rotation angle is reached, a minute movement signal from the rotation angle detection unit 41, and a sensor from a movement amount detection sensor built in the minute movement unit 32. A drive control unit 42 that inputs a signal and outputs a drive signal, and a drive unit 43 that inputs a drive signal from the drive control unit 42 and drives the minute drive element 326 are provided.

FIG. 2 shows a detailed example of the minute moving means 32 placed and fixed on the tool rest 31 shown in FIG.
Is a plan view thereof, and FIG. 6B is a side view thereof. The minute driving means 32 is mounted on the tool rest 31 and fixed on the slider rail 321, and the slider rail 321 is mounted and fixed on the L-shaped block 322.
A fine movement slider 323 capable of minute movement on the slider rail 321; a table 324 placed and fixed on the fine movement slider 323; and an L-shaped block 327 placed and fixed on the table 324. , And a tool holder 325 for holding the tool 15, and an L-shaped block 32.
2 and an L-shaped block 327, and a minute driving element 326 fixed to the L-shaped block 327. Incidentally, the minute driving element 326
For example, a piezoelectric element or an electrostrictive element is used, and the minute drive element 326 incorporates the movement amount detection sensor.

An example of operation in the case of forming minute protrusions at the entering end and the leaving end of the peripheral side surface of the fixed drum by cutting with the numerically controlled lathe 30 having such a configuration will be described with reference to the flowchart of FIG. Drives the spindle motor 13 to drive the spindle 14
While rotating the second motor 19 and the third motor 2
1 is driven to move the second slider 20 and the third slider 22 in the X and Y directions, and the tool 15 held by the tool rest 31 is positioned at the machining start point (STP1).
In the rotation angle detector 41, Z from the pulse coder 33
Phase, A phase and B phase pulse signals are counted and the main shaft 14
The rotation angle of is detected (STP2).

The fixed drum 1 set in advance
It is confirmed whether or not the rotation angle corresponding to the rush end and the release end of the peripheral side surface of No. 1 is reached (STP3), and when the rotation angle is reached, a minute movement signal is output to the drive control unit 42 (STP).
4). When the drive control unit 42 inputs the minute movement signal from the rotation angle detection unit 41, the drive signal is output to the drive unit 43 (STP5). When the drive signal is input from the drive control unit 42 to the drive unit 43, the minute drive element 326 is driven (STP6). When the minute driving element 326 is driven, that is, expands and contracts in the X direction, the L-shaped block 322 is pushed or pulled, so that the table 324 also slightly moves in the X direction. The tool 15 can be finely moved in the X direction in accordance with the fine movement of the table 324 in the X direction.

Then, the movement amount detection sensor detects the movement amount of the minute drive element 326 (STP7), and outputs the sensor signal of the detected movement amount to the drive control unit 42 (STP).
8). The drive control unit 42 compares the minute movement signal from the rotation angle detection unit 41 and the sensor signal from the movement amount detection sensor (STP9), returns to STP5 and repeats the above-described operation until the difference between them becomes zero. . That is, the drive control unit 42
Closed loop control to feed back to. At the same time as the machining by the fine movement in the X direction described above, the first motor 17
Also, processing is carried out by finely moving the first slider 18 in the Z direction by driving to form a tape running surface on the peripheral side surface of the fixed drum 11. Then, it is confirmed whether or not the machining command is completed (STP10), and when the machining command is not completed, the process returns to STP2 and the above-described operation is repeated, and when the machining command is completed, all the processes are terminated. By combining the above operations, for example, the minute projections 4, the tape running surface 5 and the leads 6 having the shapes shown in the perspective view of the fixed drum 11 of FIG. 4 and the circumferential side surface development view of the fixed drum 11 of FIG. 5 are formed. You can

The drive control section 4 of the numerically controlled lathe 30 described above.
By changing the drive signal from the fixed drum 1
The tape running surface of No. 1 can be eccentric with respect to the rotation axis and can be processed at high speed and with high accuracy. For example, in the process of assembling the rotary head device 50 as shown in FIG. 6, there is an operation of adjusting the cylindricity of the lower drum 51 and the upper drum 52 in order to improve the hitting property of the magnetic tape. Specifically, a spacer 54 is sandwiched between the lower drum 51 and the drum support 53, and a cylinder is formed so as to correspond to the uneven distribution of the air film generated between the magnetic tape and each drum due to the rotation of the rotating drum 55. It is a work to adjust the degree. At this time, the tape running surface of the lower drum 51 is
If it is formed eccentrically with respect to the upper drum 52 so as to correspond to the uneven distribution of the film, the above work can be omitted. Further, by changing the drive signal from the drive control unit 42, it is possible to form a plurality of minute protrusions at arbitrary positions on the tape running surface which is eccentric to the rotation axis.

[0017]

As described above, according to the present invention, it is possible to process the minute protrusion having a shape that further reduces the impact error at high speed and with high accuracy.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a numerically controlled lathe which is an embodiment of a drum processing device of a rotary head device according to the present invention.

2A and 2B are a plan view and a side view showing a detailed example of a main part of the numerically controlled lathe shown in FIG.

FIG. 3 is a flowchart showing an operation example of the numerically controlled lathe shown in FIG.

4 is a perspective view showing an example of a fixed head that can be processed by the numerically controlled lathe shown in FIG.

5 is a circumferential side surface development view of the fixed head shown in FIG.

6 is a perspective view showing another example of a fixed head that can be processed by the numerically controlled lathe shown in FIG.

FIG. 7 is a plan view showing an example of a numerically controlled lathe which is an example of a drum processing device of a conventional rotary head device.

FIG. 8 is a perspective view showing an example of a fixed head that can be processed by a drum processing device of a conventional rotary head device.

9 is a development view of a peripheral side surface of the fixed head shown in FIG.

[Explanation of symbols]

 10, 30 Numerically controlled lathe 11 Fixed drum 12 Chuck 13 Spindle motor 14 Spindle 15 Tool 16, 31 Tool post 17 1st motor 18 1st slider 19 2nd motor 20 2nd slider 21 3rd motor 22 3rd slider 32 Minute movement Means 321 Slider rail 322, 327 L-shaped block 323 Fine movement slider 324 Table 325 Tool holder 326 Micro drive element 33 Pulse coder 40 Control section 41 Rotation angle detection section 42 Drive control section 43 Drive section

Claims (2)

[Claims] 1. A rotating head device is provided with rotating means for holding and rotating a drum, and moving means for holding a tool and moving it in an axial direction and a radial direction of the drum, and the rotating means and the moving means are synchronized. In the drum machining device of the rotary head device for machining the drum with the tool, a fine moving unit for finely moving the tool in the radial direction of the drum in synchronization with the rotating unit is provided. Drum processing device for rotary head device. 2. A rotating means for gripping and rotating a drum of a rotary head device, and a moving means for gripping a tool and moving the tool in an axial direction and a radial direction of the drum. The rotating means and the moving means are synchronized with each other. In the drum processing device of the rotary head device for processing the drum with the tool, a minute moving means for minutely moving the tool in the radial direction of the drum, a rotation angle of the rotating means, and a movement of the minute moving means. And a controller for controlling the driving of the minute moving means based on the amount.