JPS59162402A - Method for measuring amount of eccentricity of rotary member of vtr cylinder - Google Patents

Abstract

PURPOSE:To make it possible to perform highly accurate measurement, by providing a block made of magnetic material, which faces a magnet supported at the lower end of a rotary shaft that supports a rotary cylinder with a specified interval provided, at the output end of a rotary driving system, rotating said block, thereby rotating the rotary cylinder through the magnet. CONSTITUTION:A coupling 31, which is fixed to the upper end of a shaft 22, is provided so that a block 32 made of a magnetic material is protruded toward a magnet 11 of a rotor 12 by a spring 33. Now, a VTR cylinder is positioned on a base 17, then a cylinder 18 is actuated, the shaft 22 is pushed up, and the block 32 is brought close to the magnet 11. Both the magnet 11 and the block 32 are not contacted, but the attracting force of the magnet 11 acts on the block 32. Under this state, a motor 19 is operated, and the coupling 31 is rotated through gears 26 and 24 and the shaft 22. Then the magnet 11 is rotated accordingly, and the rotor 12, a rotary shaft 2, and the cylinder 8 are also rotated. Since the eccentricity of the shaft 2 and the vibration of a rotary driving system are not transmitted to the rotary shaft 2, the amount of eccentricity of the rotary cylinder 8 can be accurately measured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a measuring device for measuring the eccentricity of a rotating member that supports a cylinder head for V'rR.
In particular, the present invention relates to a measurement method that enables measurement without being affected by the accuracy of a drive system for rotating a rotating member during measurement. [Prior Art] An example of a cylinder for a VTR is shown in FIG. This VTR cylinder has a bearing 3 on a rotating shaft 2 of a flat motor 1.
The flat motor is rotatably inserted through the motor;
The rotary cylinder 8 is fixed to the case 4 of the rotary shaft 2 by a screw 7, and is fixed to one end of the rotary shaft 2 by a screw 7. A magnetic head 9 is attached to the rotating cylinder 8. A rotor 12 is supported on a plate 10 fixed to the lower i portion of the rotating shaft 2 of the flat motor 1. The rotor 12 includes annular magnets 11 in which north poles and south poles are alternately arranged. A stator 15 having an electromagnetic coil 14 is arranged at the bottom of the case 13 which is removably supported in front of the case 4I/c.
．． When the case 4Ve is installed, the coil 14 is in the above configuration with the magnet 11 at a predetermined interval, so when a current is applied to the coil 14 to generate a magnetic field, the rotor 12
rotates to rotate the rotating cylinder 8 via the rotating shaft 2.

In a VTR cylinder having such a configuration, the eccentricity of the rotary cylinder 8 with respect to the cylinder 5 which is wound around the stationary cylinder 5 and the rotary cylinder 8 is several μm.

I request you to do the following. , there is. . Normally, the amount of eccentricity of the rotating cylinder 8 is measured with the stationary cylinder 5, the rotating cylinder 8, and the rotor 12 attached to the rotating shaft 2, and any irregularities are adjusted.

FIG. 2 shows an example of a measuring device used to measure the amount of eccentricity. In this figure, the same parts as in FIG. 1 are designated by the same reference numerals. The measuring device has a cylinder 18 and a motor 19 disposed at the bottom of a base 17 with a lever 16 formed in the center of a U-shaped groove. - A shaft 22 is rotatably connected to the rod 2,0 of the cylinder 180 via a joint 21. This shaft 22 passes through the rod 16 such that it can rotate and move up and down, and a chuck 23 is supported at its upper end. A gear 24 is fixed to the lower end of the shaft 22, and is aligned with a gear 26 fixed to the rotation shaft 25 of the motor 19. ing. A groove for positioning and holding the stationary cylinder 5 is formed at the upper end of the base 17. Also, on the outside of this groove, is there a plaque? A detector 29.30 is supported via 27.28. The detector 29 is arranged to face the 8°0 circumferential surface of the rotating cylinder of the VTR cylinder fixed in the groove, and the detector 30 is arranged to strike against the 9 rotating circumferential surface of the magnetic head. Further, when the grooved KVTR cylinder is placed in place, the lower end of the rotating shaft 2 is in a position where it can be held by the chuck 23 located at the rising end.

With such a configuration, after the VTR cylinder is fixed on the base 17, the cylinder 18 is fully activated, the chuck 23 is moved to the rising end, and the chuck 23 holds the lower end of the rotating shaft 2. let In this state, the motor 19
When operated, the shaft 22 rotates through the gears 26 and 24, and the rotating shaft 2 is rotated through the chuck 23. Then, the rotary cylinder 8 rotates, and by measuring the output of the cut-off detector 29, the amount of eccentricity can be determined by X.

Further, since the phase can be detected by the output of the detector 30, by combining the outputs of the detectors 29 and 30, the amount of eccentricity and the phase can be determined as shown in FIG.

In such a loading case, since the shaft 22 and the rotating shaft 2 are mechanically coupled to rotate the rotating shaft 2, the eccentricity or inclination of the shaft 22, or the rotational drive system consisting of the motor 19 and the gears 26 and 24 may be affected. Due to the influence of photography, etc., a difference of several micrometers occurs in the measurement results. For this reason, there are drawbacks such as a large variation in the amount of eccentricity of the rotary cylinder 8 after measurement and adjustment, making it impossible to measure with high precision.

[Purpose of the invention]

An object of the present invention is to provide a measurement method that eliminates the drawbacks of the prior art described above and enables accurate measurement without being affected by the accuracy of the rotational drive source.

[Summary of the invention]

In order to achieve the above objective, a plurality of blocks made of magnetic material are placed on the upper end of the shaft on the drive source side, and these blocks face the magnets of the rotor supported at the lower end of the rotating shaft at a predetermined interval. By rotating the block with the magnet's attractive force acting on the block, and causing the rotor to rotate following the block due to the magnet's attractive force, rotation can be achieved without applying any external mechanical force to the rotating shaft. It is characterized by being made to do.

[Embodiments of the invention]

The present invention and one embodiment will be described below with reference to the drawings.

Figures 4 and 5: show an embodiment of the present invention, and in these figures, the same parts as in Figures 1 to 3'' are:
They are indicated by the same reference numerals. A block 62 made of a magnetic material is heated on a joint 31 fixed to the upper end of the shaft 22 so as to project toward the magnet 11 of the rotor 12 by a spring 33.

In the above configuration, after the VTR cylinder is fixed on the base 17, the cylinder 18 is actuated to push up the shaft 22 and bring the block 32 closer to the magnet 11. The opening between the magnet 11 and the block 32 is made large enough to prevent the magnet 11 and the Glock 32 from coming into contact with each other and to allow the attractive force of the magnet 11 to sufficiently act on the block 32. In this state, the motor 19 is operated, the gears 26 and 24, and the shaft 2
Rotate the joint 31 via 2. Then, Prozuri 3
2 also rotates, and the magnet 11 exerting an attractive force on the block 32 is pulled by the block 32&c and rotates.

Therefore, the rotor 12, the rotating shaft 2, and the rotating cylinder 8 rotate.

At this time, the space between the magnet 11 and the block 320 is simply the magnet 1
1, mechanical forces due to eccentricity of the shaft 2, vibrations of the rotational drive system, etc. are not transmitted to the rotary shaft 2. Therefore, the amount of eccentricity of the rotating cylinder 8 can be accurately measured.

〔Effect of the invention〕

As described above, according to the present invention, a block made of a magnetic material is provided at the output end of the rotary drive system and faces the magnet supported at the lower end of the rotary shaft supporting the rotary cylinder at a predetermined interval. Rotate the magnet using the attraction force of the magnet,
Since the rotary cylinder is rotated, the rotary cylinder can be rotated without contact, without any mechanical connection between the rotary drive system and the rotary cylinder, which affects the accuracy and vibration of the rotary drive system. Highly accurate measurements can be made without any interference.

Further, there are effects such as being able to reduce variations in the amount of eccentricity of the rotating cylinder after adjustment.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an example of a VTR cylinder, Fig. 2 is a front partial sectional view of a conventional eccentricity measuring device, Fig. 3 is an output waveform diagram of the detector in Fig. 2, and Fig. 4 5 is a front partial cross-sectional view of an apparatus for carrying out the eccentricity measuring method according to the present invention, and FIG. 5 is a perspective view showing the main part of FIG. 4. DESCRIPTION OF SYMBOLS 1... Flat motor, 2... Rotating shaft, 5... Stationary cylinder, 8... Rotating cylinder, 9... Magnetic head, 11... Magnet, 12 Rotor, 15...・Stator, 1
7... Pace, 18... Cylinder, 19... Motor, 22... Shaft, 24.26... Gear, 29.30
...Phase detector, 31...Joint, 32...Block. O 1 Fig. 2 ( Fig. 3 180 360 540 rotation ＾ g 4 Akebono

Claims (1)

[Claims] With the stator of the flat motor removed, turn the rotatably supported magnetic body into the rotor of the flat motor! The magnetic body is rotated by a rotational drive source, and the rotor of the flat motor is made to face the placed magnet, and the rotor of the flat motor is measured by the rotation amount measuring means.
A method for measuring the amount of eccentricity of a rotating member of a cylinder for a VTR, characterized by measuring the amount of eccentricity of a rotating member of a cylinder for a TR.