JPH0355241B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is an apparatus for highly precisely processing a helical scan lead portion of a lower cylinder for a rotating head type magnetic recording/recording/playback device.

Prior Art The lead part of a helical scan is the most important part that guides the running of the magnetic tape, and it is necessary to process the lead angle and linearity of the lead part with high precision with respect to the upper cylinder axis. This has an extremely large impact on improving the quality of recording and playback of recordings.

Conventionally, when processing the helical scan lead part (hereinafter simply referred to as lead part) of the lower cylinder for a rotating head type magnetic recording and recording/playback device,
For example, as disclosed in Japanese Patent Application Laid-Open No. 59-142003, a lead portion is formed by turning a lower cylinder alone, and then an upper cylinder shaft and a bearing are assembled into the lower cylinder with the lead portion formed. Therefore, due to errors caused by assembly, it is difficult to assemble the lead angle on the lower cylinder with respect to the upper cylinder axis with high precision, which is one of the causes of deterioration in recording and playback performance.

Problems to be Solved by the Invention The present invention aims to make it possible to form the lead angle of the lead portion of the helical scan formed on the outer peripheral surface of the lower cylinder with high accuracy with respect to the upper cylinder axis. This is the purpose.

Means for Solving the Problems In order to achieve the above object, the present invention includes a hollow main shaft which is rotatably driven on the headstock of the bed, an annular flange plate fixed to the end of the main shaft, and a ring-shaped flange plate fixed to the end of the main shaft. A clamp stand is mounted on the bed at the opposite position, and an upper cylinder rotatably bears a lower cylinder for a rotary head type magnetic recording and recording playback device at the axis of the fixed support shaft end that penetrates the hollow main shaft and the annular flange plate. A support hole into which one end of the shaft is inserted is provided, a V-groove is provided in the clamp base to support the other end of the upper cylinder shaft on the axis of the fixed support shaft, and a V-groove is provided on the V-groove. a clamping means for pressing and fixing the other end of the upper cylinder shaft, further protruding from the flange plate a rotary drive pin whose tip is inserted into a reference hole bored in the lower cylinder;
The present invention is provided with means for processing the lead portion of the lower cylinder, which has a tool rest equipped with a cutting blade for lathe-forming the lead portion on the circumferential surface of the lower cylinder.

Effect: The above means of the present invention fits and supports one end of the upper cylinder shaft into the support hole of the fixed support shaft, presses and fixes the other end of the upper cylinder shaft by the V-groove of the clamp base and the clamp means, and rotates the shaft. When the tip of the rotational drive pin protruding from the annular flange plate is inserted into the reference hole drilled in the lower cylinder rotatably mounted on the upper cylinder shaft and the hollow main shaft is driven to rotate,
The lower cylinder is rotated on the upper cylinder axis by a rotational drive pin protruding from the annular flange plate.

Therefore, the lead angle of the lead portion that is machined on the outer circumferential surface of the lower cylinder is formed with the upper cylinder axis as the reference axis.

As a result, not only the outer circumferential surface of the lower cylinder but also the lead angle of the lead portion formed by turning on the outer circumferential surface are machined with high precision with respect to the upper cylinder axis without error.

Embodiment FIG. 1 is a schematic vertical cross-sectional view of a rotary head for a magnetic recording/recording/playback device, FIG. 2 is a front view showing an upper cylinder shaft supported state showing one embodiment of the present invention, and FIG. The figure is a plan view of the main part of FIG. 2 explaining the state in which a lead part is turned by lathe on the outer circumferential surface of the lower cylinder. 3 are spaced apart,
A support shaft fixing base 4 is arranged at a distance on the other side. A hollow main shaft 6 with an annular flange plate 5 fixed to the shaft end on the clamp stand 3 side is rotatably supported on the main spindle 2 by bearings, and the shaft portion of the main spindle 6 that protrudes toward the support shaft fixing stand 4 side includes: A drive pulley 7 with a belt suspended between it and a prime mover (not shown) is fixed.

A support shaft 8 whose shaft end is fixed to a support shaft fixing base 4
The free end of the cylinder is inserted into the hollow main shaft 6 and through the annular flange plate 5, and a support hole 9 for inserting and supporting the upper cylinder shaft end is bored in the axial direction at the end face axis of the free end. A lower cylinder 10 is attached to the flange plate 5.
A long cam surface 12 for turning the lead part 11 is formed on the outer peripheral surface of the lower cylinder 10, and a rotation driving pin 13 for the lower cylinder whose tip is inserted into a reference hole bored in the lower cylinder 10 is provided protrudingly. There is.

The clamp table 3 has a V-groove 15 for supporting the end of the upper cylinder shaft 14 inserted and fixed into the upper cylinder 10' on the center of the support hole 9, and a V-groove 15 for supporting the end of the upper cylinder shaft 14 inserted and fixed into the upper cylinder 10' on the center of the support hole 9; A hydraulic ram 16 is attached as a clamping means for holding the end portion under pressure.

Therefore, the upper cylinder shaft 1 is attached to the lower cylinder 10.
4 is rotatably inserted with a bearing, and the upper cylinder shaft 1 is
4 is inserted into the support hole 9 of the fixed support shaft 8 and the tip of the rotary drive pin 13 is inserted into the reference hole of the lower cylinder 10, and the other end is inserted into the V of the clamp base 3.
When the hollow main shaft 6 is supported in the groove 15 and held under pressure by the fluid pressure ram 16 and driven to rotate, the upper cylinder shaft 1
The lower cylinder 10 rotatably supported by
The cutting blade 19 attached to the cam follower 18, which is held pressed against the cam surface 12 of the flange plate by a spring 17, is rotated by the rotation drive pin 13 protruding from the rotating annular flange plate 5.
2, a lead portion 11 having a lead angle with respect to the upper cylinder axis 14 is turned on the outer circumferential surface of the lower cylinder 10, and both the turning of the outer circumferential surface of the lower cylinder 10 and the turning of the lead portion are performed. A highly accurate rotating circumferential surface with no errors about the upper cylinder shaft 14 is formed.

Note that the turning process of the lead part is not limited to the above embodiment in which the cam surface 12 is formed on the flange plate, but the turning process of the cutting blade is not limited to the above embodiment in which the cam surface 12 is formed on the flange plate. Movement may be controlled.

Effects of the Invention The present invention eliminates the conventional example in which a lower cylinder with a lead portion machined on its outer peripheral surface is rotatably mounted on an upper cylinder shaft by a bearing, and provides a lower cylinder in which a bearing is rotatably mounted on the upper cylinder shaft. Since both ends of the upper cylinder shaft are fixed and the lower cylinder is rotated together with the annular flange plate on the upper cylinder shaft, the lead part can be turned, so the lead angle of the lead part is the same as that of the upper cylinder shaft. Turning is performed based on the standard, and it is possible to form a highly accurate lead part with respect to the upper cylinder axis.
It is possible to improve the quality of recording and playback of recordings.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of a rotary head for a magnetic recording and recording/playback device, Figs. 2 and 3 show embodiments of the present invention, and Fig. 2 shows a shaft end of an upper cylinder that rotatably supports a lower cylinder. FIG. 3 is a partially sectional front view showing a state in which the cutting blade is turned, and FIG. 1... Bed, 2... Headstock, 3... Clamp base, 4... Support shaft fixing base, 5... Annular flange plate, 6... Hollow main shaft, 7... Drive pulley, 8...
Fixed support shaft, 9...Support hole, 10...Lower cylinder, 11...Helical scan lead portion, 13...
... Rotation drive pin, 14 ... Upper cylinder shaft, 15
... V groove, 16 ... clamping means, 19 ... cutting blade.

Claims (1)

[Claims] 1. A hollow main shaft that is rotatably driven is supported on a headstock on a bed, an annular flange plate is fixed to the end of the main shaft, a clamp table is attached on the bed at a position opposite to the flange plate, and the hollow main shaft and the annular flange are fixed to each other. A support hole is bored in the axis of the end of the fixed support shaft inserted through the plate, into which one end of the upper cylinder shaft rotatably bears the lower cylinder for the rotating head type magnetic recording and recording/playback device. A clamp stand is provided with a V-groove for supporting the other end of the upper cylinder shaft on the axis of the fixed support shaft, and a clamp means is provided on the V-groove for press-fixing the other end of the upper cylinder shaft. Further, a rotary drive pin whose tip is inserted into a reference hole drilled in the lower cylinder is protruded from the flange plate, and a turret is provided with a cutting blade for turning the helical scan lead part on the peripheral surface of the lower cylinder. A helical scan processing device for a lower cylinder for a rotating head type magnetic recording and recording/playback device.